【Java Web 程序开发】学习笔记
2020-05-13 本文已影响0人
Du1in9
参考文献：https://book.douban.com/subject/26581849/
完整源代码：https://pan.baidu.com/s/1IQUsLuFwOj_QXglHPPmqug 提取码：2647
第一章 XML基础
1.1 XML概述
1.1.1 W3C组织介绍
https://wiki.hk.xileso.top/wiki/W3C
1.1.2 什么是XML
https://baike.baidu.com/item/%E5%8F%AF%E6%89%A9%E5%B1%95%E6%A0%87%E8%AE%B0%E8%AF%AD%E8%A8%80/2885849?fromtitle=xml&fromid=86251&fr=aladdin
1.1.3 XML与HTML的比较
https://blog.csdn.net/m18633778874/article/details/79028240/
1.2 XML语法
例1-1 元素定义，注释
book.xml
<?xml version="1.0" encoding="GB2312"?>
<!--注释信息-->
<书架>
<书>
<书名>程序员的自我修养</书名>
<价格>23.5元</价格>
</书>
<书>
<书名>肖生克的救赎</书名>
<价格>20.5</价格>
</书>
</书架>
建议用notepad++编写，浏览器打开
例1-2 特殊字符
<书名><程序员的自我修养></书名>
例1-3 CDATA区
java.xml
<?xml version="1.0"?>
<java>
<![CDATA[
if(a>b&&b>c)
max=a;
]]>
</java>
1.3 DTD约束
例1-4 DTD约束
Note.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE note SYSTEM "Note.dtd">
<note>
<to>George</to>
<from>John</from>
<heading>Reminder</heading>
<body>Don't forget the meeting!</body>
</note>
Note.dtd
<?xml version="1.0" encoding="GB2312"?>
<!ELEMENT note (to, from, heading, body)>
<!ELEMENT to (#PCDATA)>
<!ELEMENT from (#PCDATA)>
<!ELEMENT heading (#PCDATA)>
<!ELEMENT body (#PCDATA)>
1.4 Schema 约束
例1-5 使用名称空间引入XML Schema文档
book1.xml
<?xml version="1.0" encoding="UTF-8"?>
<书架 xmlns="http://www.it315.org/xmlbook/schema"
xmlns:demo="http://www.it315.org/demo/schema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.it315.org/xmlbook/schema http://www.it315.org/xmlbook.xsd
http://www.it315.org/demo/schema http://www.it315.org/demo.xsd">
<书>
<书名>JavaScript网页开发</书名>
<作者>木丁西</作者>
<售价 demo:币种=”人民币”>28.00元</售价>
</书>
</书架>
例1-6 不使用名称空间引入XML Schema文档
book2.xml
<?xml version="1.0" encoding="UTF-8"?>
<书架 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="xmlbook.xsd">
<书>
<书名>JavaScript网页开发</书名>
<作者>张孝祥</作者>
<售价>28.00元</售价>
</书>
</书架>
第二章 Tomcat 开发Web站点
2.1 Web开发相关知识
2.1.1 B/S架构和C/S架构
https://blog.csdn.net/sea_snow/article/details/81187804
2.1.2 通信协议
https://www.cnblogs.com/xhwy/archive/2012/03/03/2378293.html
2.1.3 Web资源
https://www.cnblogs.com/linkworld/p/7573043.html
例2-1 dynamic.html
现在的时间是：
<script type="text/javascript">
document.write(new Date());
</script>
2.2 安装Tomcat
2.2.1 Tomcat简介
https://baike.baidu.com/item/tomcat/255751?fr=aladdin
2.2.2 Tomcat安装和启动
个人不建议配置tomcat8，后面用Myclipse做项目不方便
https://blog.csdn.net/oqqKen12345/article/details/82839914
例2-2 dynamic.jsp
Now the time is:<br>
<%=new java.util.Date()%>
（运行Tomcat，jsp文件放在Apache-Tomcat-8.5.45\webapps\Me\文件夹，再访问http://localhost:8080/Me/dynamic.jsp即可）
2.3 发布Web应用
2.3.1 什么是Web应用
https://www.jianshu.com/p/ddbe852179fe
2.3.2 配置Web应用虚拟目录（选做）
https://blog.csdn.net/baolibin528/article/details/38034101
2.3.3 配置Web应用默认页面（选做）
https://blog.csdn.net/weixin_43740680/article/details/92086233
2.3.4 Tomcat的管理平台
https://blog.csdn.net/cuijiying/article/details/78526982
2.4 Eclipse中配置Tomcat服务器
https://jingyan.baidu.com/article/219f4bf7b57b20de442d38ac.html
第三章 HTTP协议
3.1 HTTP概述
3.1.1 HTTP介绍
https://www.runoob.com/http/http-intro.html
3.1.2 HTTP1.0和HTTP1.1
https://blog.csdn.net/FU250/article/details/90763223
3.1.3 HTTP消息
https://blog.csdn.net/huangjin0507/article/details/52170460
3.2 HTTP请求信息
https://blog.csdn.net/u010256388/article/details/68491509/
例3-1 GET.html
<html>
<body>
<form action="" method="get">
姓名：<input type="text" name="name" style="width:150px"/><p/>
年龄：<input type="text" name="age" style="width:150px"/><p/>
<input type="submit" value="提交"/><p/>
</form>
</body>
</html>
例3-2 POST.html
<html>
<body>
<form action="" method="post">
姓名：<input type="text" name="name" style="width:150px"/><p/>
年龄：<input type="text" name="age" style="width:150px"/><p/>
<input type="submit" value="提交"/><p/>
</form>
</body>
</html>
中文乱码咋办？如图：
打开Tomcat，访问http://localhost:8080/Three/GET.html，输入Jack，40，再看请求头消息
打开Tomcat，访问http://localhost:8080/Three/POST.html，输入Jack，40，再看请求头消息
3.3 HTTP响应信息
3.3.1 HTTP响应状态行
https://blog.csdn.net/zjs_csdns/article/details/89004295?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase
3.3.2 HTTP响应消息头
https://www.runoob.com/http/http-header-fields.html
3.4 HTTP其他头字段
3.4.1 通用头字段
https://blog.csdn.net/u010369338/article/details/69566058/
3.4.2 实体头字段
https://www.iteye.com/blog/zengguo1988-283702
第四章 Servlet技术
4.1 Servlet开发入门
4.1.1 Servlet接口
https://www.cnblogs.com/weibanggang/p/9464307.html
4.1.2 实现第一个Servlet程序
先找到servlet-api.jar，设置环境变量
set classpath=%classpath%;E:\apache-tomcat-8.5.45\apache-tomcat-8.5.45\lib\servlet-api.jar
例4-1 HelloWorldServlet.java
package Java_Web.Four;//这是包名，也就是文件夹的路径，我这里是E:\Java_Web\Four
import java.io.*;
import javax.servlet.*;
public class HelloWorldServlet extends GenericServlet{
public void service(ServletRequest request,ServletResponse response) throws ServletException,IOException{
PrintWriter out = response.getWriter();
out.println("XXXXX");
}
}
编译
javac HelloWorldServlet.java
在webapps文件夹新建xxx\WEB-INF\classes目录，然后将包放进去
在WEB-INF中，新建web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<servlet>
<servlet-name>HelloWorldServlet</servlet-name>
<servlet-class>Java_Web.Four.HelloWorldServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldServlet</servlet-name>
<url-pattern>/HelloWorldServlet</url-pattern>
</servlet-mapping>
</web-app>
<!--
<servlet>用于注册Servlet
<servlet-name>HelloWorldServlet</servlet-name>指定servlet的名称为HelloWorldServlet，你也可以改成其他的
<servlet-class>java_web.HelloWorldServlet</servlet-class>指定servlet完整的类名，要和你编写的.java 文件的类名相同
<servlet-mapping>用于映射servlet对外访问虚拟路径，它的<servlet-name>名字必须和<servlet>中的<servlet-name>相同
<url-pattern>是指定该servlet的虚拟路径,该路径以正斜杠(/)开头，表示当前web应用程序的根目录
-->
启动Tomcat，访问http://localhost:8080/Four/HelloWorldServlet即可
①如果出现以下情况，多半是web.xml书写格式有误，一点点失误就会报错，巨坑
②因为每次编译都要设置环境变量比较麻烦，可以把语句存在一个文本里，下次直接套用，例如我的就是：
cd /d E:\apache-tomcat-8.5.45\apache-tomcat-8.5.45\webapps\chapter04\WEB-INF\classes\Java_Web\Four
set classpath=%classpath%;E:\apache-tomcat-8.5.45\apache-tomcat-8.5.45\lib\servlet-api.jar
javac xxx.java
4.1.3 Servlet的生命周期
https://www.runoob.com/servlet/servlet-life-cycle.html
4.2 Servlet高级应用
4.2.1 HttpServlet
例4-3
RequestMethodServlet.java
package Java_Web.Four;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestMethodServlet extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
PrintWriter out = response.getWriter();
out.println("this is doGetmethod");
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
PrintWriter out = response.getWriter();
out.println("this is doPostmethod");
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<servlet>
<servlet-name>RequestMethodServlet</servlet-name>
<servlet-class>Java_Web.Four.RequestMethodServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RequestMethodServlet</servlet-name>
<url-pattern>/RequestMethodServlet</url-pattern>
</servlet-mapping>
</web-app>
开启tomcat，访问http://localhost:8080/chapter04/RequestMethodServlet
在webapp\chapter04目录下新建form.html
<form action="/chapter04/RequestMethodServlet" method="post">
姓名：<input type="text" name="name" style="width:150px"/><p/>
密码：<input type="text" name="psw" style="width:150px"/><p/>
<input type="submit" value="提交"/><p/>
</form>
访问http://localhost:8080/chapter04/form.html
点击提交，会显示“this is doPostmethod”，所以我们知道采用POST方式请求Servlet时，会自动调用doPost( )方法
4.2.2 使用MyEclipse开发Servlet
新建Web项目
新建Servlet程序
对Servlet的doPost( )和doGet( )方法进行修改
如果servers窗口不见了，点击windows--show views--others
直接在Myclipse里运行
4.2.3 Servlet虚拟路径的映射
https://blog.csdn.net/qq_24042659/article/details/82967306
4.3 ServletConfig和ServletContext
4.3.1 ServletConfig接口
Servlet运行期间，通常需要一些辅助信息，可以在web.xml中使用<init-param>进行配置
<param-name>表示参数名称，<param-value>表示参数值
新建Servlet程序，配置web.xml
<servlet>
<display-name>TestServlet02</display-name>
<servlet-name>TestServlet02</servlet-name>
<servlet-class>Java_Web.Four.TestServlet02</servlet-class>
<init-param>
<param-name> encoding </param-name>
<param-value> UTF-8 </param-value>
</init-param>
</servlet>
TestServlet02.java
package Java_Web.Four;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet02 extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
PrintWriter out = response.getWriter();
ServletConfig config=this.getServletConfig();
String param=config.getInitParameter("encoding");
out.println("encoding="+param);
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
this.doGet(request,response);
}
}
编译，运行，访问
可以看出，ServletConfig对象可以获得web.xml中的参数信息
4.3.2 ServletContext接口
①获取初始化参数
例4-6
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<servlet>
<display-name>TestServlet03</display-name>
<servlet-name>TestServlet03</servlet-name>
<servlet-class>Java_Web.Four.TestServlet03</servlet-class>
</servlet>
<context-param>
<param-name> companyName </param-name>
<param-value> alibaba </param-value>
</context-param>
<context-param>
<param-name> address </param-name>
<param-value> earth </param-value>
</context-param>
<servlet-mapping>
<servlet-name>TestServlet03</servlet-name>
<url-pattern>/TestServlet03</url-pattern>
</servlet-mapping>
</web-app>
TestServlet03.java
package Java_Web.Four;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet03 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out = response.getWriter();
// 得到ServletContext对象
ServletContext context = this.getServletContext();
// 得到包含所有初始化参数名的Enumeration对象
Enumeration<String> paramNames = context.getInitParameterNames();
// 遍历所有的初始化参数名，得到相应的参数值，打印到控制台
out.println("all the paramName and paramValue are following:"+"<br>");
// 遍历所有的初始化参数名，得到相应的参数值并打印
while (paramNames.hasMoreElements()) {
String name = paramNames.nextElement();
String value = context.getInitParameter(name);
out.println(name + ": " + value);
out.println("<br>");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}
编译，运行，访问
②实现共享数据
例4-7
TestServlet04.java
package Java_Web.Four;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet04 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletContext context = this.getServletContext();
// 通过setAttribute()方法设置属性值
context.setAttribute("data", "this servlet save data");
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
例4-8
TestServlet05.java
package Java_Web.Four;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet05 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
ServletContext context = this.getServletContext();
// 通过getAttribute()方法获取属性值
String data = (String) context.getAttribute("data");
out.println(data);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
编译，启动，分别访问，可知ServletContext存储数据可被多个Servlet共享
③读取Web应用资源文件
在classes目录下新建资源文件itcast.properties
Company=abcdefg
Address=earth
例4-9
TestServlet06.java
package Java_Web.Four;
import java.io.*;
import java.util.Properties;
import javax.servlet.*;
import javax.servlet.http.*;
public class TestServlet06 extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletContext context = this.getServletContext();
PrintWriter out = response.getWriter();
InputStream in = context
.getResourceAsStream("/WEB-INF/classes/itcast.properties");
Properties pros = new Properties();
pros.load(in);
out.println("Company=" + pros.getProperty("Company") + "<br>");
out.println("Address=" + pros.getProperty("Address") + "<br>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
第五章 请求和响应
5.1 HttpServletResponse对象
5.1.1 发送状态码
5.1.2 发送响应消息头
5.1.3 发送响应消息体
①getOutputStream()方法
②getWriter()方法
例5-1
PrintServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class PrintServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String data="hello_motherfucker!";
OutputStream out=response.getOutputStream();// 获取输出流对象
out.write(data.getBytes()); // 输出字符串信息
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<servlet>
<display-name>PrintServlet</display-name>
<servlet-name>PrintServlet</servlet-name>
<servlet-class>Java_Web.Five.PrintServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>PrintServlet</servlet-name>
<url-pattern>/PrintServlet</url-pattern>
</servlet-mapping>
</web-app>
5.2 HttpServletResponse应用
5.2.1 中文输出乱码问题
法一：例5-3
ChineseServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ChineseServlet extends HttpServlet {
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("utf-8");//设置字符编码方式
String data="中国";
PrintWriter out = response.getWriter();
out.println(data);
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
}
修改浏览器编码：https://jingyan.baidu.com/article/cd4c2979f2a664756e6e60db.html
法二：例5-4
ChineseServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ChineseServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String data="中国";
response.setContentType("text/html;charset=utf-8");//设置HttpServletResponse和浏览器编码为utf-8
PrintWriter out = response.getWriter();
out.println(data);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
}
5.2.2 网页定时刷新并跳转
例5-5
RefreshServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RefreshServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 2秒后刷新并跳转到指定网页
response.setHeader("Refresh","2;URL=https://www.jianshu.com/u/32aab16373de");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
例5-6
RefreshServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RefreshServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setHeader("Refresh","1");// 每隔1秒定时刷新当前页面
response.getWriter().println(new java.util.Date());// 输出当前时间
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.2.3 禁止浏览器缓存页面
例5-7
CacheServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class CacheServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
response.setDateHeader("Expires",0);
response.setHeader("Cache-Control","no-cache");
response.setHeader("Pragma","no-cache");
PrintWriter out = response.getWriter();
out.println("本次响应的随机数为：" + Math.random());
out.println("<form action='NotServlet'" + "method='POST'>" +
"第一个参数：<input type='text' name='p1'><br>" +
"第二个参数：<textarea name='p2'></textarea><br>" +
"<input type='submit' value='提交'> " +
"</form>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.2.4 请求重定向
例5-8
login.html
<!--把表单内容提交到chapter05工程下的LoginServlet-->
<form action="/chapter05/LoginServlet" method="post">
用户名： <input type="text" name="username" /><br>
密 码： <input type="password" name="password" /><br>
<input type="submit" value="登录" />
</form>
welcome.html
<html>
<head>
<title>Insert title here</title>
</head>
<body>
欢迎你 ♂ 登录成功！
</body>
</html>
LoginServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
// 用HttpServletRequest对象的getParameter()方法获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 假设用户名和密码分别为：Du1in9和123
if (("Du1in9").equals(username) &&("123").equals(password)) {
response.sendRedirect("/chapter05/welcome.html");// 如果用户名和密码正确，重定向到 welcome.html
}
else {
response.sendRedirect("/chapter05/login.html");// 如果用户名和密码错误，重定向到login.html
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.3 HttpServletRequest对象
5.3.1 获取请求行信息
例5-11
RequestLineServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestLineServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
// 获取请求行的相关信息
out.println("getMethod : " + request.getMethod() + "<br>");
out.println("getRequestURI : " + request.getRequestURI() + "<br>");
out.println("getQueryString : " + request.getQueryString() + "<br>");
out.println("getProtocol : " + request.getProtocol() + "<br>");
out.println("getContextPath : " + request.getContextPath() + "<br>");
out.println("getPathInfo : " + request.getPathInfo() + "<br>");
out.println("getPathTranslated : " + request.getPathTranslated()+ "<br>");
out.println("getServletPath : " + request.getServletPath() + "<br>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.3.2 获取请求消息头
例5-12
RequestHeadersServlet.java
package Java_Web.Five;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestHeadersServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
// 获取请求消息中所有头字段
Enumeration headerNames = request.getHeaderNames();
// 使用循环遍历所有请求头，并通过getHeader()方法获取一个指定名称的头字段
while (headerNames.hasMoreElements()) {
String headerName = (String) headerNames.nextElement();
out.print(headerName + " : " + request.getHeader(headerName)+ "<br>");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
利用Referer请求头防止“盗链”
例5-13
download.html
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<a href="/chapter05/DownManagerServlet">download</a>
</body>
</html>
例5-14
DownManagerServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class DownManagerServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
String referer = request.getHeader("referer");// 获取referer头的值
String sitePart = "http://" + request.getServerName();// 获取访问地址
// 判断referer头是否为空，这个头的首地址是否以sitePart开始的
if (referer != null && referer.startsWith(sitePart)) {
out.println("Downloading ...");// 处理正在下载的请求
}
else {// 非法下载请求跳转到download.html页面
RequestDispatcher rd = request.getRequestDispatcher("/download.html");
rd.forward(request, response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.3.3 获取请求消息体
例5-15
form.html
<form action="/chapter05/RequestBodyServlet" method="post">
用户名：<input type="text" name="username"><br>
密 码：<input type="password" name="password"><br>
<input type="submit" value="提交">
</form>
RequestBodyServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestBodyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
InputStream in = request.getInputStream();// 获取输入流对象
byte[] buffer = new byte[1024]; // 定义1024个字节的数组
StringBuilder sb = new StringBuilder(); // 创建StringBuilder对象
int len;
while ((len = in.read(buffer)) != -1) {// 循环读取数组中的数据
sb.append(new String(buffer, 0, len));
}
System.out.println(sb);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.4 HttpServletRequest应用
5.4.1 获取请求参数
form.html
<form action="/chapter05/RequestParamsServlet" method="POST">
用户名：<input type="text" name="username"><br>
密 码：<input type="password" name="password"><br>
爱 好：
<input type="checkbox" name="hobby" value="sing">唱
<input type="checkbox" name="hobby" value="dance">跳
<input type="checkbox" name="hobby" value="rap">rap
<input type="checkbox" name="hobby" value="basketball">篮球<br>
<input type="submit" value="提交">
</form>
RequestParamsServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestParamsServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
String name = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("用户名：" + name);
System.out.println("密 码：" + password);
String[] hobbys= request.getParameterValues("hobby");
System.out.print("爱好：");
for (int i = 0; i < hobbys.length; i++) {
System.out.print(hobbys[i]+" ");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.4.2 请求参数的中文乱码问题
RequestParamsServlet.java中设置中文编码即可
request.setCharacterEncoding("gbk");
5.4.3 获取网络连接信息
RequestNetServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestNetServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html ;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("getRemoteAddr : " + request.getRemoteAddr() + "<br>");
out.println("getRemoteHost : " + request.getRemoteHost() + "<br>");
out.println("getRemotePort : " + request.getRemotePort() + "<br>");
out.println("getLocalAddr : " + request.getLocalAddr() + "<br>");
out.println("getLocalName : " + request.getLocalName() + "<br>");
out.println("getLocalPort : " + request.getLocalPort() + "<br>");
out.println("getServerName : " + request.getServerName() + "<br>");
out.println("getServerPort : " + request.getServerPort() + "<br>");
out.println("getScheme : " + request.getScheme() + "<br>");
out.println("getRequestURL : " + request.getRequestURL() + "<br>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
5.4.4 通过Request对象传递数据
setAttribute()方法，getAttribute()方法，removeAttribute()方法，getAttributeNames()方法
5.5 RequestDispatcher对象的应用
5.5.1 RequestDispatcher接口
5.5.2 请求转发
RequestForwardServlet.java
package Java_Web.Five;
import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestForwardServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
// 将数据存储到request对象中
request.setAttribute("company", "阿里巴巴");
RequestDispatcher dispatcher = request.getRequestDispatcher("/ResultServlet");
dispatcher.forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
ResultServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class ResultServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();// 获取PrintWriter对象用于输出信息
String company = (String) request.getAttribute("company");// 获取request请求对象中保存的数据
if (company != null) {
out.println("公司名称：" + company + "<br>");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
然后web.xml中配置他俩的映射，访问
5.5.3 请求包含
IncludingServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class IncludingServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
PrintWriter out = response.getWriter();
RequestDispatcher rd = request.getRequestDispatcher("/IncludedServlet?p1=fuck");
out.println("before including" + "<br>");
rd.include(request, response);
out.println("after including" + "<br>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
IncludedServlet.java
package Java_Web.Five;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class IncludedServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 设置响应时使用的字符编码
response.setContentType("text/html;charset=utf-8");
response.setCharacterEncoding("utf-8");
PrintWriter out = response.getWriter();
out.println("中国" + "<br>");
out.println("URI:" + request.getRequestURI() + "<br>");
out.println("QueryString:" + request.getQueryString() + "<br>");
out.println("parameter p1:" + request.getParameter("p1") + "<br>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
然后web.xml中配置他俩的映射，访问
第六章 会话及其会话技术
6.1 会话概述
https://www.cnblogs.com/luoxn28/p/5513789.html
6.2 Cookie对象
6.2.1 什么是Cookie
https://blog.csdn.net/qq_17452939/article/details/80901985
6.2.2 Cookie API
https://blog.csdn.net/u011541946/article/details/90273259
6.3 Cookie之显示用户上次访问时间
源代码编译时报错，因为date.toLocaleString()已过时，我用DateFormat.format(Date date)进行了取代
LastAccessServlet.java
package Java_Web.Six;
import java.io.IOException;
import java.util.Date;
import java.text.SimpleDateFormat;
import javax.servlet.ServletException;
import javax.servlet.http.*;
public class LastAccessServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 指定服务器输出内容的编码方式UTF-8，防止发生乱码
response.setContentType("text/html;charset=utf-8");
String lastAccessTime = null;
// 获取所有的cookie，并将这些cookie存放在数组中
Cookie[] cookies = request.getCookies();
for (int i = 0; cookies != null && i < cookies.length; i++) {
// 如果cookie的名称为lastAccess,则获取该cookie的值
if ("lastAccess".equals(cookies[i].getName())) {
lastAccessTime = cookies[i].getValue();
break;
}
}
// 判断是否存在名称为lastAccess的cookie
if (lastAccessTime == null) {
response.getWriter().print("您是首次访问本站！！！");
}
else {
response.getWriter().print("您上次的访问时间是： " + lastAccessTime);
}
// 创建cookie,将当前时间作为cookie的值发送给客户端
String currentTime = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date());
Cookie cookie = new Cookie("lastAccess", currentTime);
// 发送 cookie
response.addCookie(cookie);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
// TODO Auto-generated method stub
this.doPost(req, resp);
}
}
6.4 Session对象
6.4.1 什么是Session
https://blog.csdn.net/q_sea__/article/details/79430215
6.4.2 HttpSession API
https://blog.csdn.net/u011541946/article/details/90442127
6.4.3 Session 超时管理
https://www.cnblogs.com/d0minic/p/12258853.html
6.5 Session之实现购物车
ListBookServlet.java
package Java_Web.Six;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.ServletException;
class Book implements Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String name;
public Book() {
}
public Book(String id, String name) {
this.id = id;
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
class BookDB {
private static Map<String, Book> books = new LinkedHashMap<String, Book>();
static {
books.put("1", new Book("1", "javaweb开发"));
books.put("2", new Book("2", "jdbc开发"));
books.put("3", new Book("3", "java基础"));
books.put("4", new Book("4", "struts开发"));
books.put("5", new Book("5", "spring开发"));
}
// 获得所有的图书
public static Collection<Book> getAll() {
return books.values();
}
// 根据指定的id获得图书
public static Book getBook(String id) {
return books.get(id);
}
}
public class ListBookServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=utf-8");
PrintWriter out = resp.getWriter();
Collection<Book> books = BookDB.getAll();
out.write("本站提供的图书有：<br>");
for (Book book : books) {
String url = "/chapter06/PurchaseServlet?id=" + book.getId();
out.write(book.getName() + "<a href='" + url
+ "'>点击购买</a><br>");
}
}
}
PurchaseServlet.java
换共有类：
public class PurchaseServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@SuppressWarnings("unchecked")
public void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
// 获得用户购买的商品
String id = req.getParameter("id");
if (id == null) {
// 如果id为null，重定向到ListBookServlet页面
String url = "/chapter06/ListBookServlet";
resp.sendRedirect(url);
return;
}
Book book = BookDB.getBook(id);
// 创建或者获得用户的Session对象
HttpSession session = req.getSession();
// 从Session对象中获得用户的购物车
List<Book> cart = (List) session.getAttribute("cart");
if (cart == null) {
// 首次购买，为用户创建一个购物车(List集合模拟购物车)
cart = new ArrayList<Book>();
// 将购物城存入Session对象
session.setAttribute("cart", cart);
}
// 将商品放入购物车
cart.add(book);
// 创建Cookie存放Session的标识号
Cookie cookie = new Cookie("JSESSIONID", session.getId());
cookie.setMaxAge(60 * 30);
cookie.setPath("/chapter06");
resp.addCookie(cookie);
// 重定向到购物车页面
String url = "/chapter06/CartServlet";
resp.sendRedirect(url);
}
}
CartServlet.java
换共有类：
public class CartServlet extends HttpServlet {
@SuppressWarnings("unchecked")
public void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
resp.setContentType("text/html;charset=utf-8");
PrintWriter out = resp.getWriter();
// 变量cart引用用户的购物车
List<Book> cart = null;
// 变量pruFlag标记用户是否买过商品
boolean purFlag = true;
// 获得用户的session
HttpSession session = req.getSession(false);
// 如果session为null，purFlag置为false
if (session == null) {
purFlag = false;
}
else {
// 获得用户购物车
cart = (List) session.getAttribute("cart");
// 如果用的购物车为null，purFlag置为false
if (cart == null) {
purFlag = false;
}
}
/*如果purFlag为false，表明用户没有购买图书 重定向到ListServlet页面*/
if (!purFlag) {
out.write("对不起！您还没有购买任何商品！<br>");
} else {
// 否则显示用户购买图书的信息
out.write("您购买的图书有：<br>");
double price = 0;
for (Book book : cart) {
out.write(book.getName() + "<br>");
}
}
}
}
访问http://localhost:8080/chapter06/ListBookServlet.java
6.6 Session之实现用户登录
Login.html
<form name="reg" action="/chapter06/LoginServlet" method="post">
用户名: <input name="username" type="text" /><br/>
密码： <input name="password" type="password" /><br/>
<input type="submit" value="提交" id="bt" />
</form>
IndexServlet.java
package Java_Web.Six;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.ServletException;
class User {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
public class IndexServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 解决乱码问题
response.setContentType("text/html;charset=utf-8");
// 创建或者获取保存用户信息的Session对象
HttpSession session = request.getSession();
User user = (User) session.getAttribute("user");
if (user == null) {
response.getWriter().print("您还没有登录，请<a href='/chapter06/Login.html'>登录</a>");
}
else {
response.getWriter().print("您已登录，欢迎你，" + user.getUsername() + "！");
response.getWriter().print("<a href='/chapter06/LogoutServlet'>退出</a>");
// 创建Cookie存放Session的标识号
Cookie cookie = new Cookie("JSESSIONID", session.getId());
cookie.setMaxAge(60 * 30);
cookie.setPath("/chapter06");
response.addCookie(cookie);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
LoginServlet.java
换共有类：
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("password");
PrintWriter pw = response.getWriter();
//假设正确的用户名 是Du1in9 密码是123
if (("Du1in9").equals(username) && ("123").equals(password)) {
User user = new User();
user.setUsername(username);
user.setPassword(password);
request.getSession().setAttribute("user", user);
response.sendRedirect("/chapter06/IndexServlet");
}
else {
pw.write("用户名或密码错误，登录失败");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
LogoutServlet.java
换共有类：
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
// 将Session对象中的User对象移除
request.getSession().removeAttribute("user");
response.sendRedirect("/chapter06/IndexServlet");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
访问http://localhost:8080/chapter06/IndexServlet
6.7 Session之实现验证码
Login.html
<form name="reg" action="/chapter06/LoginServlet" method="post">
用户名: <input name="username" type="text" /><br />
密码： <input name="password" type="password" /><br />
验证码：<input type="text" name="check_code">
<img src="/chapter06/CheckServlet"><br>
<input type="submit" value="提交" id="bt" />
</form>
CheckServlet.java
package Java_Web.Six;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import java.awt.image.*;
import javax.imageio.ImageIO;
public class CheckServlet extends HttpServlet{
private static int WIDTH = 60; //验证码图片宽度
private static int HEIGHT = 20; //验证码图片高度
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
HttpSession session = request.getSession();
response.setContentType("image/jpeg");
ServletOutputStream sos = response.getOutputStream();
//设置浏览器不要缓存此图片
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
//创建内存图象并获得其图形上下文
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
//产生随机的认证码
char [] rands = generateCheckCode();
//产生图像
drawBackground(g);
drawRands(g,rands);
//结束图像的绘制过程，完成图像
g.dispose();
//将图像输出到客户端
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ImageIO.write(image, "JPEG", bos);
byte [] buf = bos.toByteArray();
response.setContentLength(buf.length);
//下面的语句也可写成：bos.writeTo(sos);
sos.write(buf);
bos.close();
sos.close();
//将当前验证码存入到Session中
session.setAttribute("check_code",new String(rands));
//直接使用下面的代码将有问题，Session对象必须在提交响应前获得
//request.getSession().setAttribute("check_code",new String(rands));
}
//生成一个4字符的验证码
private char [] generateCheckCode()
{
//定义验证码的字符表
String chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
char [] rands = new char[4];
for(int i=0; i<4; i++)
{
int rand = (int)(Math.random() * 36);
rands[i] = chars.charAt(rand);
}
return rands;
}
private void drawRands(Graphics g , char [] rands)
{
g.setColor(Color.BLACK);
g.setFont(new Font(null,Font.ITALIC|Font.BOLD,18));
//在不同的高度上输出验证码的每个字符
g.drawString("" + rands[0],1,17);
g.drawString("" + rands[1],16,15);
g.drawString("" + rands[2],31,18);
g.drawString("" + rands[3],46,16);
System.out.println(rands);
}
private void drawBackground(Graphics g)
{
//画背景
g.setColor(new Color(0xDCDCDC));
g.fillRect(0, 0, WIDTH, HEIGHT);
//随机产生120个干扰点
for(int i=0; i<120; i++)
{
int x = (int)(Math.random() * WIDTH);
int y = (int)(Math.random() * HEIGHT);
int red = (int)(Math.random() * 255);
int green = (int)(Math.random() * 255);
int blue = (int)(Math.random() * 255);
g.setColor(new Color(red,green,blue));
g.drawOval(x,y,1,0);
}
}
}
LoginServlet.java
package Java_Web.Six;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
import javax.servlet.http.*;
class User {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("password");
String checkCode = request.getParameter("check_code");
String savedCode = (String) request.getSession().getAttribute("check_code");
PrintWriter pw = response.getWriter();
if (("Du1in9").equals(username) && ("123").equals(password)&& checkCode.equals(savedCode)) {
User user = new User();
user.setUsername(username);
user.setPassword(password);
request.getSession().setAttribute("user", user);
response.sendRedirect("/chapter06/IndexServlet");
}
else if (checkCode.equals(savedCode)) {
pw.write("用户名或密码错误，登录失败");
}
else {
pw.write("验证码错误");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
doGet(request, response);
}
}
访问http://localhost:8080/chapter06/Login.html
第七章 JSP技术
7.1 JSP概述
7.1.1 什么是JSP
https://www.runoob.com/jsp/jsp-intro.html
simple.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<title>boy next ♂ door</title>
<body>
当前访问时间是：
<%out.print(new java.util.Date().toLocaleString());%>
</body>
</html>
访问http://localhost:8080/chapter07/simple.jsp
7.1.2 JSP运行原理
https://zhidao.baidu.com/question/476724087.html
7.2 JSP基本语法
JSP注释信息不会被发送到客户瑞
comment.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%-- 这个是注释内容 --%>
</body>
</html>
7.3 JSP指令
①修改报错页面
page.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%int a=1/0;%>
</body>
</html>
page1.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" errorPage="error.jsp"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%int a=1/0;%>
</body>
</html>
error.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<h2>抱歉♂服务器出现故障♂正在解决♂请稍候。。。。。。。</h2>
</body>
</html>
②通用报错页面
web.xml
<error-page>
<error-code>404</error-code>
<location>/404.jsp</location>
</error-page>
<error-page>
<error-code>500</error-code>
<location>/500.jsp</location>
</error-page>
404.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<h2>404：你他妈在访问什么玩意</h2>
</body>
</html>
500.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<h2>通用500错误处理页面</h2>
</body>
</html>
访问http://localhost:8080/chapter07/page.jsp
访问http://localhost:8080/chapter07/abcdefg.jsp
7.4 JSP隐式对象
7.4.1 隐式对象
7.4.2 out对象
out.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%
out.println("first line<br>");
response.getWriter().println("second line<br>");
%>
</body>
</html>
out1.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" buffer="0kb"%>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%
out.println("first line<br>");
response.getWriter().println("second line<br>");
%>
</body>
</html>
7.4.3 pageContext对象
pageContext.jsp
<%
HttpServletRequest req=(HttpServletRequest)pageContext.getRequest();
String x = request.getRemoteAddr();
out.println("本机的IP地址为："+x);
%>
访问http://127.0.0.1:8080/chapter07/pageContext.jsp
pageContextDemo.jsp
<%
pageContext.setAttribute("company", "阿里巴巴",pageContext.PAGE_SCOPE);
Object x = pageContext.getAttribute("company",pageContext.PAGE_SCOPE);
out.println("公司名称为：" + x);
%>
7.4.4 exception对象
price.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ page errorPage="execp.jsp"%>
<%
String p=request.getParameter("price");
double x=Double.parseDouble(p);
out.println("Total price:"+x*5);
%>
execp.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ page isErrorPage="true"%>
<%
out.println("exception.toString:"+"<br>");
out.println(exception.toString());
out.println("<br>");
out.println("exception.getMessage():"+"<br>");
out.println(exception.getMessage());
%>
访问http://localhost:8080/chapter07/price.jsp?price=3.5
访问http://localhost:8080/chapter07/price.jsp?price=Du1in9
7.5 JSP标签
7.5.1 <jsp:include>标签
included.jsp
<%@ page contentType="text/html;charset=GB2312"%>
<%Thread.sleep(2000);%>
你~<br>
<jsp:include page="included1.jsp" flush="true" />
included1.jsp
<%@ page contentType="text/html;charset=GB2312"%>
<%Thread.sleep(2000);%>
是~<br>
<jsp:include page="included2.jsp" flush="true" />
included2.jsp
<%@ page contentType="text/html;charset=GB2312"%>
<%Thread.sleep(2000);%>
猪~<br>
访问http://localhost:8080/chapter07/included.jsp
7.5.2 <jsp:forward>标签
jspforward.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<jsp:forward page="welcome.jsp" />
welcome.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<title>Insert title here</title>
<body>
你好，欢迎进入首页，当前访问时间是：
<%out.print(new java.util.Date());%>
</body>
</html>
第八章 JavaBean组件
8.1 JavaBean概述
https://blog.csdn.net/keep12moving/article/details/92666633
8.2 反射（略）
8.3 内省（略）
8.4 JSP标签访问JavaBean
8.4.1 <jsp:useBean>标签
Manager.java
package Java_Web.Eight;
class Employee {
private String company;
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
}
public class Manager extends Employee {
private double bonus;
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
}
useBean.jsp
<%@ page language="java" pageEncoding="GBK"%>
<html>
<body>
<jsp:useBean id="manager" scope="page" class="Java_Web.Eight.Manager" />
</body>
</html>
8.4.2 <jsp:setProperty>标签
①property属性单独使用
setProperty.jsp
<%@ page language="java" pageEncoding="GBK" import="Java_Web.Eight.Manager"%>
<html>
<body>
<jsp:useBean id="manager" class="Java_Web.Eight.Manager" />
<jsp:setProperty name="manager" property="bonus" />
<%
manager = (Manager) pageContext.getAttribute("manager");
out.write("bonus属性的值为:"+manager.getBonus());
%>
</body>
</html>
访问http://localhost:8080/chapter08/setProperty.jsp?bonus=500
修改Manager.java
package Java_Web.Eight;
class Employee {
private String company;
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
}
public class Manager extends Employee {
private double bonus=500;
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
}
访问http://localhost:8080/chapter08/setProperty.jsp
修改setProperty.jsp
<%@ page language="java" pageEncoding="GBK" import="Java_Web.Eight.Manager"%>
<html>
<body>
<jsp:useBean id="manager" class="Java_Web.Eight.Manager" />
<jsp:setProperty name="manager" property="*" />
<%
manager = (Manager) pageContext.getAttribute("manager");
out.write("bonus属性的值为:"+manager.getBonus()+"<br />");
out.write("company属性的值为:"+manager.getCompany());
%>
</body>
</html>
访问http://localhost:8080/chapter08/setProperty.jsp?bonus=600&company=阿里巴巴
②property属性和param属性混合使用
setProperty.jsp
<body>
<form action="">
公司<input type="text" name="corp"> <br/>
奖金<input type="text" name="reward"> <br/>
<input type="submit" value="提交">
</form>
<jsp:useBean id="manager" class="Java_Web.Eight.Manager" />
<jsp:setProperty name="manager" property="company" param="corp" />
<jsp:setProperty name="manager" property="bonus" param="reward" />
<%
manager = (Manager) pageContext.getAttribute("manager");
out.write("bonus属性的值为:"+manager.getBonus()+"<br />");
out.write("company属性的值为:"+manager.getCompany());
%>
</body>
③property属性和value属性混合使用
setProperty.jsp
<body>
<jsp:useBean id="manager" class="Java_Web.Eight.Manager" />
<jsp:setProperty name="manager" property="company" value="阿里巴巴" />
<jsp:setProperty name="manager" property="bonus" value="1000.0" />
<%
manager = (Manager) pageContext.getAttribute("manager");
out.write("bonus属性的值为:"+manager.getBonus()+"<br />");
out.write("company属性的值为:"+manager.getCompany());
%>
</body>
setProperty.jsp
<%@ page language="java" pageEncoding="GBK" import="Java_Web.Eight.Manager" import="java.util.Date" import="java.text.SimpleDateFormat"%>
<html>
<body>
<%
Date date = new Date();
pageContext.setAttribute("date", date);
%>
<jsp:useBean id="manager" class="Java_Web.Eight.Manager" />
<jsp:setProperty name="manager" property="birthday" value="${date }" />
<%
manager = (Manager) pageContext.getAttribute("manager");
String formatDate = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(manager.getBirthday());
out.write("birthday属性的值为:"+formatDate);
%>
</body>
</html>
Manager.java
package Java_Web.Eight;
import java.util.Date;
class Employee {
private String company;
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
}
public class Manager extends Employee {
private double bonus = 500.0;
private Date birthday;
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
}
8.4.3 <jsp:getProperty>标签
User.java
package Java_Web.Eight;
public class User {
private String name;
private String gender;
private String education;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getEducation() {
return education;
}
public void setEducation(String education) {
this.education = education;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
login.jsp
<body>
<form action="/chapter08/userInfo.jsp" method="post">
姓名:<input type="text" name="name" /> <br />
性别:<input type="radio" name="gender" value="man" checked="checked" />man
<input type="radio" name="gender" value="woman" />woman <br/>
学历:<select name="education">
<option value="select">请选择</option>
<option value="high_school_student">high_school_student</option>
<option value="undergraduate">undergraduate</option>
<option value="graduate">graduate</option>
<option value="doctor">doctor</option>
</select> <br/>
邮箱:<input type="text" name="mail" /> <br />
<input type="submit" value="提交"/>
</form>
</body>
userInfo.jsp
<body>
<jsp:useBean id="user" class="Java_Web.Eight.User" />
<jsp:setProperty name="user" property="*" />
<jsp:setProperty name="user" property="email" param="mail" />
姓名:<jsp:getProperty name="user" property="name" /> <br />
性别:<jsp:getProperty name="user" property="gender" /> <br />
学历:<jsp:getProperty name="user" property="education" /> <br />
邮箱:<jsp:getProperty name="user" property="email" />
</body>
8.5 BeanUtils 工具（略）
第九章 JSP开发模型
9.1 JSP开发模型
https://blog.csdn.net/zl5230/article/details/105851338
9.2 案例
Calculator.java
package Java_Web.Nine;
import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;
public class Calculator {
// firstNum表示第一个运算数
private String firstNum;
// secondNum表示第二个运算数
private String secondNum;
// operator表示运算符
private char operator;
// error用于封装错误信息
private Map<String, String> errors = new HashMap<String, String>();
// 属性setter和getter方法
public Map<String, String> getErrors() {
return errors;
}
public void setErrors(Map<String, String> errors) {
this.errors = errors;
}
public String getFirstNum() {
return firstNum;
}
public void setFirstNum(String firstNum) {
this.firstNum = firstNum;
}
public String getSecondNum() {
return secondNum;
}
public void setSecondNum(String secondNum) {
this.secondNum = secondNum;
}
public char getOperator() {
return operator;
}
public void setOperator(char operator) {
this.operator = operator;
}
/*calculate()方法根据传入的运算数和符号进行运算*/
public String calculate() {
BigDecimal result = null;
BigDecimal first = new BigDecimal(firstNum);
BigDecimal second = new BigDecimal(secondNum);
switch (operator) {
case '+':
result = first.add(second);
break;
case '-':
result = first.subtract(second);
break;
case '*':
result = first.multiply(second);
break;
case '/':
if ("0".equals(secondNum)) {
throw new RuntimeException("除数不能为0！");
}
result = first.divide(second);
break;
default:
break;
}
return result.toString();
}
/*validate()方法用于验证表单传入的数据是否合法*/
public boolean validate() {
// flag是标识符，如果数据合法flag为true，反之为false
boolean flag = true;
Pattern p = Pattern.compile("\\d+");// 正则表达式，匹配数字
if (firstNum == null || "".equals(firstNum)) { // 判断不能为空
errors.put("firstNum", "第一个运算数不能为空");
flag = false;
} else if (!p.matcher(firstNum).matches()) { // 判断不能为非数字
errors.put("firstNum", "第一个运算数必须为数字");
flag = false;
}
if (secondNum == null || "".equals(secondNum)) {
errors.put("secondNum", "第二个运算数不能为空");
flag = false;
} else if (!p.matcher(secondNum).matches()) {
errors.put("secondNum", "第二个运算数必须为数字");
flag = false;
}
return flag;
}
}
calculator.jsp
<%@ page language="java" pageEncoding="GBK" import="java.util.Map"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>calculator</title>
</head>
<body>
<jsp:useBean id="calculator" class="Java_Web.Nine.Calculator" />
<jsp:setProperty property="*" name="calculator" />
<%
if (calculator.validate()) {
%>
<font color="green">运算结果:
<jsp:getProperty property="firstNum" name="calculator" />
<jsp:getProperty property="operator" name="calculator" />
<jsp:getProperty property="secondNum" name="calculator" />
=<%=calculator.calculate()%></font>
<%
}
else {
Map<String, String> errors = calculator.getErrors();
pageContext.setAttribute("errors", errors);
}
%>
<form action="" method="post">
第一个运算数：<input type="text" name="firstNum" />
<font color="red">${errors.firstNum}</font> <br />
运算符: <select name="operator" style="margin-left: 100px">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select> <br />
第二个运算数： <input type="text" name="secondNum" />
<font color="red">${errors.secondNum}</font> <br />
<input type="submit" value="计算" />
</form>
</body>
</html>
