Servlet-上传
2020-06-20 本文已影响0人
通灵路耳
1、前端页面upload.html
<!DOCTYPE html>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<!-- 1、method必须是post
2、enctype表示提交的是二进制文件
3、type="file"表示上传
-->
<form action="login" method="post" enctype="multipart/form-data">
英雄名称:<input type="text" name="heroName" /> <br>
上传头像 : <input type="file" name="filepath" /> <br>
<input type="submit" value="上传">
</form>
2、导入jar包
3、配置web.xml
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>com.llhc.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
4、找到servlet接受上传文件
package com.llhc;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import java.util.List;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class HelloServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response) {
String filename = null;
try {
//准备：上传文件对象
DiskFileItemFactory factory = new DiskFileItemFactory();
//准备：上传文件Servlet
ServletFileUpload upload = new ServletFileUpload(factory);
//准备：设置上传文件的大小限制为1M
factory.setSizeThreshold(1024 * 1024);
//获取：获取传输来的文件，放入List集合
List items = null;
try {
items = upload.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
}
//获取：遍历文件
Iterator iter = items.iterator();
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();
if (!item.isFormField()) {
//设置：文件名
filename = System.currentTimeMillis() + ".jpg";
//设置：通过uploaded自动获取到文件地址
String photoFolder =request.getServletContext().getRealPath("uploaded");
File f = new File(photoFolder, filename);
f.getParentFile().mkdirs();
//获取文件输入流
InputStream is = item.getInputStream();
//获取文件输出流
FileOutputStream fos = new FileOutputStream(f);
byte b[] = new byte[1024 * 1024];
int length = 0;
while (-1 != (length = is.read(b))) {
fos.write(b, 0, length);
}
fos.close();
} else {
System.out.println(item.getFieldName());
String value = item.getString();
value = new String(value.getBytes("ISO-8859-1"), "UTF-8");
System.out.println(value);
}
}
String html = "<img width='200' height='150' src='uploaded/%s' />";
response.setContentType("text/html");
PrintWriter pw= response.getWriter();
pw.format(html, filename);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
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