23-26年 学习笔记

Java - SpringBootWeb 案例

2024-05-21  本文已影响0人  Du1in9

👉 在线笔记:https://du1in9.github.io/springboot_demo.github.io/

1 准备工作

1.1 需求

1.2 环境准备

1. 准备数据库表 (dept、emp)

-- 部门管理
create table dept(
    id int unsigned primary key auto_increment comment '主键ID',
    name varchar(10) not null unique comment '部门名称',
    create_time datetime not null comment '创建时间',
    update_time datetime not null comment '修改时间'
) comment '部门表';

insert into dept (id, name, create_time, update_time) values(1,'学工部',now(),now()),(2,'教研部',now(),now()),(3,'咨询部',now(),now()), (4,'就业部',now(),now()),(5,'人事部',now(),now());

-- 员工管理(带约束)
create table emp (
    id int unsigned primary key auto_increment comment 'ID',
    username varchar(20) not null unique comment '用户名',
    password varchar(32) default '123456' comment '密码',
    name varchar(10) not null comment '姓名',
    gender tinyint unsigned not null comment '性别, 说明: 1 男, 2 女',
    image varchar(300) comment '图像',
    job tinyint unsigned comment '职位, 说明: 1 班主任,2 讲师, 3 学工主管, 4 教研主管, 5 咨询师',
    entrydate date comment '入职时间',
    dept_id int unsigned comment '部门ID',
    create_time datetime not null comment '创建时间',
    update_time datetime not null comment '修改时间'
) comment '员工表';

INSERT INTO emp
    (id, username, password, name, gender, image, job, entrydate,dept_id, create_time, update_time) VALUES
    (1,'jinyong','123456','金庸',1,'1.jpg',4,'2000-01-01',2,now(),now()),
    (2,'zhangwuji','123456','张无忌',1,'2.jpg',2,'2015-01-01',2,now(),now()),
    (3,'yangxiao','123456','杨逍',1,'3.jpg',2,'2008-05-01',2,now(),now()),
    (4,'weiyixiao','123456','韦一笑',1,'4.jpg',2,'2007-01-01',2,now(),now()),
    (5,'changyuchun','123456','常遇春',1,'5.jpg',2,'2012-12-05',2,now(),now()),
    (6,'xiaozhao','123456','小昭',2,'6.jpg',3,'2013-09-05',1,now(),now()),
    (7,'jixiaofu','123456','纪晓芙',2,'7.jpg',1,'2005-08-01',1,now(),now()),
    (8,'zhouzhiruo','123456','周芷若',2,'8.jpg',1,'2014-11-09',1,now(),now()),
    (9,'dingminjun','123456','丁敏君',2,'9.jpg',1,'2011-03-11',1,now(),now()),
    (10,'zhaomin','123456','赵敏',2,'10.jpg',1,'2013-09-05',1,now(),now()),
    (11,'luzhangke','123456','鹿杖客',1,'11.jpg',5,'2007-02-01',3,now(),now()),
    (12,'hebiweng','123456','鹤笔翁',1,'12.jpg',5,'2008-08-18',3,now(),now()),
    (13,'fangdongbai','123456','方东白',1,'13.jpg',5,'2012-11-01',3,now(),now()),
    (14,'zhangsanfeng','123456','张三丰',1,'14.jpg',2,'2002-08-01',2,now(),now()),
    (15,'yulianzhou','123456','俞莲舟',1,'15.jpg',2,'2011-05-01',2,now(),now()),
    (16,'songyuanqiao','123456','宋远桥',1,'16.jpg',2,'2007-01-01',2,now(),now()),
    (17,'chenyouliang','123456','陈友谅',1,'17.jpg',NULL,'2015-03-21',NULL,now(),now());

2. 创建 springboot 工程,引入对应的起步依赖(web、mybatis、mysql 驱动、lombok)

3. 配置文件 application.properties 中引入 mybatis 的配置信息,准备对应的实体类

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/tlias
spring.datasource.username=root
spring.datasource.password=123456

mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
mybatis.configuration.map-underscore-to-camel-case=true
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Dept {
    private Integer id; // ID
    private String name; // 部门名称
    private LocalDateTime createTime; // 创建时间
    private LocalDateTime updateTime; // 修改时间
}
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Emp {
    private Integer id;         // ID
    private String username;    // 用户名
    private String password;    // 密码
    private String name;        // 姓名
    private Short gender;       // 性别, 1 男, 2 女
    private String image;       // 图像 url
    private Short job;          // 职位, 1 班主任, 2 讲师, 3 学工主管, 4 教研主管, 5 咨询师
    private LocalDate entrydate;        // 入职日期
    private Integer deptId;             // 部门 ID
    private LocalDateTime createTime;   // 创建时间
    private LocalDateTime updateTime;   // 修改时间
}

4. 准备对应的 Mapper、Service (接口、实现类)、Controller 基础结构

@RestController
public class DeptController {}
@RestController
public class EmpController {}

@Mapper
public interface DeptMapper {}
@Mapper
public interface EmpMapper {}

@Service
public interface DeptService {}
@Service
public interface EmpService {}
public class DeptServiceImpl {}
public class EmpServiceImpl {}

1.3 开发规范

1. Restful:REST(REpresentational State Transfer),表述性状态转换,它是一种软件架构风格

2. 统一响应结果

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result {
    private Integer code;// 响应码,1 代表成功; 0 代表失败
    private String msg;  // 响应信息 描述字符串
    private Object data; // 返回的数据

    // 增删改 成功响应
    public static Result success(){
        return new Result(1,"success",null);
    }
    // 查询 成功响应
    public static Result success(Object data){
        return new Result(1,"success",data);
    }
    // 失败响应
    public static Result error(String msg){
        return new Result(0,msg,null);
    }
}

2 部门管理

2.1 查询部门

请求路径:/depts

请求方式:GET

接口描述:该接口用于部门列表数据查询

@Slf4j
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;
    
    @GetMapping("/depts")
    public Result list(){
        log.info("查询全部部门数据");
        List<Dept> deptList =  deptService.list();
        return Result.success(deptList);
    }
}
@Service
public class DeptServiceImpl implements DeptService {
    @Autowired
    private DeptMapper deptMapper;

    @Override
    public List<Dept> list() {
        return deptMapper.list();
    }
}

public interface DeptService {
    List<Dept> list();
}
@Mapper
public interface DeptMapper {
    @Select("select * from dept")
    List<Dept> list();
}

请求参数:无

响应数据:application/json

// postman: get: http://localhost:8080/depts`
{
    "code": 1,
    "msg": "success",
    "data": [
        {
            "id": 1,
            "name": "学工部",
            "createTime": "2024-05-17T14:05:21",
            "updateTime": "2024-05-17T14:05:21"
        },
        ...
        {
            "id": 5,
            "name": "人事部",
            "createTime": "2024-05-17T14:05:21",
            "updateTime": "2024-05-17T14:05:21"
        }
    ]
}

前后端联调:在资料中提供的 “前端工程” 文件夹中启动 nginx,访问 http://localhost:90 测试功能

2.2 删除部门

请求路径:/depts/{id}

请求方式:DELETE

接口描述:该接口用于根据 ID 删除部门数据

@Slf4j
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;
    
    @DeleteMapping("/depts/{id}")
    public Result delete(@PathVariable Integer id){
        log.info("根据id删除部门:{}", id);
        deptService.delete(id);
        return Result.success();
    }
}
@Service
public class DeptServiceImpl implements DeptService {
    @Autowired
    private DeptMapper deptMapper;

    @Override
    public void delete(Integer id) {
        deptMapper.deleteById(id);
    }
}

public interface DeptService {
    void delete(Integer id);
}
@Mapper
public interface DeptMapper {
    @Delete("delete from dept where id = #{id}")
    void deleteById(Integer id);
}

请求参数:路径参数

响应数据:application/json

// postman: delete: http://localhost:8080/depts/5
{
    "code": 1,
    "msg": "success",
    "data": null
}

前后端联调:在资料中提供的 “前端工程” 文件夹中启动 nginx,访问 http://localhost:90 测试功能

2.3 新增部门

请求路径:/depts

请求方式:POST

接口描述:该接口用于添加部门数据

@Slf4j
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;
    
    @PostMapping("/depts")
    public Result add(@RequestBody Dept dept){
        log.info("新增部门: {}" , dept);
        deptService.add(dept);
        return Result.success();
    }
}
@Service
public class DeptServiceImpl implements DeptService {
    @Autowired
    private DeptMapper deptMapper;

    @Override
    public void add(Dept dept) {
        dept.setCreateTime(LocalDateTime.now());
        dept.setUpdateTime(LocalDateTime.now());
        deptMapper.insert(dept);
    }
}

public interface DeptService {
    void add(Dept dept);
}
@Mapper
public interface DeptMapper {
    @Insert("insert into dept(name, create_time, update_time) values(#{name},#{createTime},#{updateTime})")
    void insert(Dept dept);
}

请求参数:application/json

响应数据:application/json

// postman: post: { "name": "消防部" }
{
    "code": 1,
    "msg": "success",
    "data": null
}

前后端联调:在资料中提供的 “前端工程” 文件夹中启动 nginx,访问 http://localhost:90 测试功能

2.4 修改部门

2.4.1 根据 id 查询

请求路径:/depts/{id}

请求方式:GET

接口描述:该接口用于根据 ID 查询部门数据

@GetMapping("/depts/{id}")
public Result find(@PathVariable Integer id){
    log.info("根据id查询部门:{}", id);
    Dept dept =  deptService.find(id);
    return Result.success(dept);
}
@Override
public Dept find(Integer id) {
    return deptMapper.findById(id);
}

Dept find(Integer id);
@Select("select * from dept where id = #{id}")
Dept findById(Integer id);

请求参数:路径参数

响应数据:application/json

// postman: get: http://localhost:8080/depts/3
{
    "code": 1,
    "msg": "success",
    "data": {
        "id": 3,
        "name": "咨询部",
        "createTime": "2024-05-17T19:39:41",
        "updateTime": "2024-05-17T19:39:41"
    }
}

2.4.2 修改部门

请求路径:/depts

请求方式:PUT

接口描述:该接口用于修改部门数据

@PutMapping ("/depts")
public Result put(@RequestBody Dept dept){
    log.info("修改部门");
    Dept dept2 =  deptService.find(dept.getId());
    deptService.put(dept2, dept.getId(), dept.getName());
    return Result.success();
}
@Override
public void put(Dept dept, Integer id, String name) {
    dept.setCreateTime(LocalDateTime.now());
    dept.setUpdateTime(LocalDateTime.now());
    deptMapper.put(id, name);
}

public interface DeptService {
    void put(Dept dept, Integer id, String name);
}
@Update("update dept set name = #{name} where id = #{id}")
void put(Integer id, String name);

请求参数:application/json

响应数据:application/json

// postman: put: { "id": 1, "name": "公安部" }
{
    "code": 1,
    "msg": "success",
    "data": null
}

前后端联调:在资料中提供的 “前端工程” 文件夹中启动 nginx,访问 http://localhost:90 测试功能

3 员工管理

3.1 分页查询

3.1.1 分页查询

请求路径:/emps

请求方式:GET

接口描述:该接口用于员工列表数据的条件分页查询

@GetMapping("/emps")
public Result page(@RequestParam(defaultValue = "1") Integer page,
                   @RequestParam(defaultValue = "10") Integer pageSize){
    log.info("分页查询:{},{}",page, pageSize);
    PageBean pageBean = empService.page(page, pageSize);
    return Result.success(pageBean);
}
public PageBean page(Integer page, Integer pageSize) {
    Long count = empMapper.count();
    Integer start = (page - 1) * pageSize;
    List<Emp> empList = empMapper.page(start, pageSize);
    PageBean pageBean = new PageBean(count, empList);
    return pageBean;
}

PageBean page(Integer page, Integer pageSize);
@Select("select count(*) from emp")
public Long count();

@Select("select * from emp limit #{start}, #{pageSize}")
public List<Emp> page(Integer start, Integer pageSize);

请求参数:queryString

响应数据:application/json

// postman: get: http://localhost:8080/emps?page=2&pageSize=5
{
    "code": 1,
    "msg": "success",
    "data": {
        "total": 17,
        "rows": [
            {
                "id": 6,
                "username": "xiaozhao",
                "password": "123456",
                "name": "小昭",
                "gender": 2,
                "image": "6.jpg",
                "job": 3,
                "entrydate": "2013-09-05",
                "deptId": 1,
                "createTime": "2024-05-17T14:05:21",
                "updateTime": "2024-05-17T14:05:21"
            },
            ...
            {
                "id": 10,
                "username": "zhaomin",
                "password": "123456",
                "name": "赵敏",
                "gender": 2,
                "image": "10.jpg",
                "job": 1,
                "entrydate": "2013-09-05",
                "deptId": 1,
                "createTime": "2024-05-17T14:05:21",
                "updateTime": "2024-05-17T14:05:21"
            }
        ]
    }
}

分页插件 PageHelper:

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.4.6</version>
</dependency>
@Override
public PageBean page(Integer page, Integer pageSize) {
    PageHelper.startPage(page,pageSize);
    List<Emp> empList = empMapper.list();
    Page<Emp> p = (Page<Emp>) empList;
    PageBean pageBean = new PageBean(p.getTotal(), p.getResult());
    return pageBean;
}
@Select("select * from emp")
public List<Emp> list();

3.1.2 分页查询(带条件)

@GetMapping
public Result page(@RequestParam(defaultValue = "1") Integer page,
                   @RequestParam(defaultValue = "10") Integer pageSize,
                   String name, Short gender,
                   @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,
                   @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end){
    log.info("分页查询, 参数: {},{},{},{},{},{}",page,pageSize,name,gender,begin,end);
    PageBean pageBean = empService.page(page,pageSize,name,gender,begin,end);
    return Result.success(pageBean);
}
@Override
public PageBean page(Integer page, Integer pageSize, String name, Short gender, LocalDate begin, LocalDate end) {
    PageHelper.startPage(page,pageSize);
    List<Emp> empList = empMapper.list(name, gender, begin, end);
    Page<Emp> p = (Page<Emp>) empList;
    PageBean pageBean = new PageBean(p.getTotal(), p.getResult());
    return pageBean;
}

PageBean page(Integer page, Integer pageSize,String name, Short gender,LocalDate begin,LocalDate end);
<mapper namespace="com.itheima.mapper.EmpMapper">
    <select id="list" resultType="com.itheima.pojo.Emp">
        select * from emp
        <where>
            <if test="name != null and name != ''">
                name like concat('%',#{name},'%')
            </if>
            <if test="gender != null">
                and gender = #{gender}
            </if>
            <if test="begin != null and end != null">
                and entrydate between #{begin} and #{end}
            </if>
        </where>
        order by update_time desc
    </select>
</mapper>

public List<Emp> list(String name, Short gender, LocalDate begin, LocalDate end);
// postman:get:http://localhost:8080/emps?page=1&pageSize=5&name=张&gender=1&begin=2000-01-01&end=2010-01-01
{
    "code": 1,
    "msg": "success",
    "data": {
        "total": 1,
        "rows": [
            {
                "id": 14,
                "username": "zhangsanfeng",
                "password": "123456",
                "name": "张三丰",
                "gender": 1,
                "image": "14.jpg",
                "job": 2,
                "entrydate": "2002-08-01",
                "deptId": 2,
                "createTime": "2024-05-17T14:05:21",
                "updateTime": "2024-05-17T14:05:21"
            }
        ]
    }
}

3.2 删除员工

请求路径:/emps/{ids}

请求方式:DELETE

接口描述:该接口用于批量删除员工的数据信息

@DeleteMapping("emps/{ids}")
public Result delete(@PathVariable List<Integer> ids){
    log.info("批量删除操作, ids:{}",ids);
    empService.delete(ids);
    return Result.success();
}
@Override
public void delete(List<Integer> ids) {
    empMapper.delete(ids);
}

void delete(List<Integer> ids);
<mapper namespace="com.itheima.mapper.EmpMapper">
    <delete id="delete">
        delete from emp
        where id in
        <foreach collection="ids" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>
</mapper>

void delete(List<Integer> ids);

请求参数:路径参数

响应数据:application/json

// postman: delete: http://localhost:8080/emps/15,16,17
{
    "code": 1,
    "msg": "success",
    "data": null
}

3.3 新增员工

请求路径:/emps

请求方式:POST

接口描述:该接口用于添加员工的信息

@PostMapping("/emps")
public Result save(@RequestBody Emp emp){
    log.info("新增员工, emp: {}",emp);
    empService.save(emp);
    return Result.success();
}
@Override
public void save(Emp emp) {
    emp.setCreateTime(LocalDateTime.now());
    emp.setUpdateTime(LocalDateTime.now());
    empMapper.insert(emp);
}

void save(Emp emp);
@Insert("insert into emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time) values(#{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime})")
void insert(Emp emp);

请求参数:application/json

响应数据:application/json

/* postman: post: 
{
  "image": "https://web-framework.oss-cn-hangzhou.aliyuncs.com/2022-09-03-07-37-38222.jpg",
  "username": "linpingzhi",
  "name": "林平之",
  "gender": 1,
  "job": 1,
  "entrydate": "2022-09-18",
  "deptId": 1
}  */   
{
    "code": 1,
    "msg": "success",
    "data": null
}

3.4 修改员工

3.4.1 查询回显

请求路径:/emps/{id}

请求方式:GET

接口描述:该接口用于根据主键ID查询员工的信息

@GetMapping("/emps/{id}")
public Result getById(@PathVariable Integer id){
    log.info("根据ID查询员工信息, id: {}",id);
    Emp emp = empService.getById(id);
    return Result.success(emp);
}
@Override
public Emp getById(Integer id) {
    return empMapper.getById(id);
}

Emp getById(Integer id);
@Select("select * from emp where id = #{id}")
Emp getById(Integer id);

请求参数:路径参数

响应数据:application/json

/* postman: get: http://localhost:8080/emps/1
{
    "code": 1,
    "msg": "success",
    "data": {
        "id": 1,
        "username": "jinyong",
        "password": "123456",
        "name": "金庸",
        "gender": 1,
        "image": "1.jpg",
        "job": 4,
        "entrydate": "2000-01-01",
        "deptId": 2,
        "createTime": "2024-05-18T19:10:18",
        "updateTime": "2024-05-18T19:10:18"
    }
}

3.4.2 修改员工

请求路径:/emps

请求方式:PUT

接口描述:该接口用于修改员工的数据信息

@PutMapping("/emps")
public Result update(@RequestBody Emp emp){
    log.info("更新员工信息 : {}", emp);
    empService.update(emp);
    return Result.success();
}
@Override
public void update(Emp emp) {
    emp.setUpdateTime(LocalDateTime.now());
    empMapper.update(emp);
}

void update(Emp emp);
<mapper namespace="com.itheima.mapper.EmpMapper">
    <update id="update">
        update emp
        <set>
            <if test="username != null and username != ''">
                username = #{username},
            </if>
            ...
            <if test="updateTime != null">
                update_time = #{updateTime}
            </if>
        </set>
        where id = #{id}
    </update>
</mapper>

void update(Emp emp);

请求参数:application/json

响应数据:application/json

/* postman: put: body: raw:
{
  "id": 1,
  "image": "https://web-framework.oss-cn-hangzhou.aliyuncs.com/2022-09-03-07-37-38222.jpg",
  "username": "linpingzhi",
  "name": "林平之",
  "gender": 1,
  "job": 1,
  "entrydate": "2022-09-18",
  "deptId": 1
}   */
{
    "code": 1,
    "msg": "success",
    "data": null
}

4 文件上传

4.1 简介

文件上传,是指将本地图片、视频、音频等文件上传到服务器,供其他用户浏览或下载的过程

1. 前端页面三要素

<!-- 1. 表单提交方式 post-->
<!-- 2. 表单的 enctype 属性 multipart/form-data -->
<form action="/upload" method="post" enctype="multipart/form-data">
    姓名: <input type="text" name="username"><br>
    年龄: <input type="text" name="age"><br>
    头像: <input type="file" name="image"><br>    
    <!-- 3. 表单项 type=“file” -->
    <input type="submit" value="提交">    
</form>

2. 服务端接收文件

@Slf4j
@RestController
public class UploadController {
    @PostMapping("/upload")
    public Result upload(String username, Integar age, MultipartFile image){
        log.info("文件上传: {}, {}, {}", username, age, image);
        return Result.success();
    }
}

4.2 本地存储

在服务端,接收到上传上来的文件之后,将文件存储在本地服务器磁盘中

@PostMapping("/upload")
public Result upload(String username , Integer age , MultipartFile image) throws Exception {
    // 1. 获取原始文件名
    String originalFilename = image.getOriginalFilename();
    // 2. 构造唯一的文件名 (不能重复) - uuid (通用唯一识别码)
    int index = originalFilename.lastIndexOf(".");
    String extname = originalFilename.substring(index);
    String newFileName = UUID.randomUUID().toString() + extname;
    // 3. 将文件存储在服务器的磁盘目录中 C:\Develop\JavaStudy\images
    image.transferTo(new File("C:\\Develop\\JavaStudy\\images"+newFileName));
    return Result.success();
}
/*
    String getOriginalFilename();       // 获取原始文件名
    void transferTo(File dest);         // 将接收的文件转存到磁盘文件中
    long getSize();                     // 获取文件的大小, 单位: 字节
    byte[] getBytes();                  // 获取文件内容的字节数组
    InputStream getInputStream();       // 获取接收到的文件内容的输入流
*/

在 SpringBoot 中,文件上传,默认单个文件允许最大大小为 1M。如果需要上传大文件,可以进行如下配置:

#配置单个文件最大上传大小
spring.servlet.multipart.max-file-size=10MB
#配置单个请求最大上传大小(一次请求可以上传多个文件)
spring.servlet.multipart.max-request-size=100MB

4.3 阿里云 OSS

4.3.1 准备工作

阿里云是阿里巴巴集团旗下全球领先的云计算公司,也是国内最大的云服务提供商

阿里云对象存储 OSS(Object Storage Service),是一款海量、安全、低成本、高可靠的云存储服务

使用OSS,您可以通过网络随时存储和调用包括文本、图片、音频和视频等在内的各种文件

AccessKey ID: LTAI5tSH18FLKGFhWgsuJsGS
AccessKey Secret: *******************

4.3.2 快速入门程序

<!--阿里云OSS-->
<dependency>
    <groupId>com.aliyun.oss</groupId>
    <artifactId>aliyun-sdk-oss</artifactId>
    <version>3.15.1</version>
</dependency>
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
    <groupId>javax.activation</groupId>
    <artifactId>activation</artifactId>
    <version>1.1.1</version>
</dependency>
<!-- no more than 2.3.3-->
<dependency>
    <groupId>org.glassfish.jaxb</groupId>
    <artifactId>jaxb-runtime</artifactId>
    <version>2.3.3</version>
</dependency>
// 官方示例代码
public class Demo {
    public static void main(String[] args) throws Exception {
        String endpoint = "https://oss-cn-beijing.aliyuncs.com";
        String accessKeyId = "LTAI5tSH18FLKGFhWgsuJsGS";
        String accessKeySecret = "*******************";
        String bucketName = "web-framework2024-5-8-01";
        String objectName = "test.jpg";
        String filePath= "C:\\Develop\\JavaStudy\\images\\test.jpg";
        ...
    }
}

4.3.3 案例集成 OSS

请求路径:/upload

请求方式:POST

接口描述:上传图片接口

@RestController
public class UploadController {
    @Autowired
    private AliOSSUtils aliOSSUtils;

    @PostMapping("/upload")
    public Result upload(MultipartFile image) throws IOException {
        String url = aliOSSUtils.upload(image);
        return Result.success(url);
    }
}
// 官方示例代码
@Component
public class AliOSSUtils {
    private String endpoint = "https://oss-cn-beijing.aliyuncs.com";
    private String accessKeyId = "LTAI5tSH18FLKGFhWgsuJsGS";
    private String accessKeySecret = "*******************";
    private String bucketName = "web-framework2024-5-8-01";
    ...
}

请求参数:multipart/form-data

响应数据:application/json

// postman: post: body: form-data: image(file) => test.jpg
{
    "code": 1,
    "msg": "success",
    "data": "https://web-framework2024-5-8-01.oss-cn-beijing.aliyuncs.com/dbb28c6d-9dfe-4e87-a6e0-4bc392ebd02f.jpg"
}

5 配置文件

1. 参数配置化

@Component
public class AliOSSUtils {
    @Value("${aliyun.oss.endpoint}")
    private String endpoint ;
    @Value("${aliyun.oss.accessKeyId}")
    private String accessKeyId ;
    @Value("${aliyun.oss.accessKeySecret}")
    private String accessKeySecret ;
    @Value("${aliyun.oss.bucketName}")
    private String bucketName ;
    ...
}
aliyun.oos.endpoint: https://oss-cn-beijing.aliyuncs.com
aliyun.oos.accessKeyId: LTAI5tSH18FLKGFhWgsuJsGS
aliyun.oos.accessKeySecret: *******************
aliyun.oos.bucketName: web-framework2024-5-8-01

2. yml 配置文件

spring:
  #数据库连接信息
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/tlias
    username: root
    password: 123456
  #文件上传的配置
  servlet:
    multipart:
      max-file-size: 10MB
      max-request-size: 100MB 
#Mybatis配置
mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true
#阿里云OSS
aliyun:
  oss:
    endpoint: https://oss-cn-beijing.aliyuncs.com
    accessKeyId: LTAI5tSH18FLKGFhWgsuJsGS
    accessKeySecret: 5wPyUojv5seKI5XqsTbrexcHHIoCwD
    bucketName: web-framework2024-5-8-01

3. @ConfigurationProperties

@Value 注解只能一个一个的进行外部属性的注入

@ConfigurationProperties 可以批量的将外部的属性配置注入到 bean 对象的属性中

@Data
@Component
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliOSSProperties {
    private String endpoint;
    private String accessKeyId;
    private String accessKeySecret;
    private String bucketName;
}

@Component
public class AliOSSUtils {...}

6 登录校验

6.1 登录认证

请求路径:/login

请求方式:POST

接口描述:该接口用于员工登录 Tlias 智能学习辅助系统,登录完毕后,系统下发 JWT 令牌

@Slf4j
@RestController
public class LoginController {
    @Autowired
    private EmpService empService;

    @PostMapping("/login")
    public Result login(@RequestBody Emp emp){
        log.info("员工登录: {}", emp);
        Emp e = empService.login(emp);
        return e != null ? Result.success() : Result.error("用户名或密码错误");
    }
}
@Override
public Emp login(Emp emp) {
    return empMapper.getByUsernameAndPassword(emp);
}

Emp login(Emp emp);
@Select("select * from emp where username = #{username} and password = #{password}")
Emp getByUsernameAndPassword(Emp emp);

联调测试,发现 bug:在未登录情况下,我们也可以直接访问部门管理、员工管理等功能

6.2 登录校验

6.2.1 会话技术

会话:用户打开浏览器访问 web 服务器的资源,会话建立,有一方断开连接,会话结束。在一次会话中可以包含多次请求和响应

会话跟踪:一种维护浏览器状态的方法,服务器识别多次请求是否来自于同一浏览器,以便在同一次会话的多次请求间共享数据

1. 客户端会话跟踪技术:Cookie

2. 服务端会话跟踪技术:Session

3. 令牌技术

6.2.2 令牌 JWT

JSON Web Token 定义了一种简洁的、自包含的格式,用于在通信双方以 json 数据格式安全的传输信息

Base64:是一种基于64个可打印字符(A-Z a-z 0-9 + /)来表示二进制数据的编码方式

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>
public class JwtUtils {
    private static String signKey = "itheima";
    private static Long expire = 43200000L;

    public static String generateJwt(Map<String, Object> claims){
        String jwt = Jwts.builder()
            .addClaims(claims)
            .signWith(SignatureAlgorithm.HS256, signKey)
            .setExpiration(new Date(System.currentTimeMillis() + expire))
            .compact();
        return jwt;
    }

    public static Claims parseJWT(String jwt){
        Claims claims = Jwts.parser()
            .setSigningKey(signKey)
            .parseClaimsJws(jwt)
            .getBody();
        return claims;
    }
}
@PostMapping("/login")
public Result login(@RequestBody Emp emp){
    Emp e = empService.login(emp);
    if (e != null){
        Map<String, Object> claims = new HashMap<>();
        claims.put("id", e.getId());
        claims.put("name", e.getName());
        claims.put("username", e.getUsername());
        
        String jwt = JwtUtils.generateJwt(claims);
        return Result.success(jwt);
    }
    return Result.error("用户名或密码错误");
}

请求参数:application/json

响应数据:application/json

/* postman: post: body: raw:
{
    "username": "zhangwuji",
    "password": "123456"
}   */
{
    "code": 1,
    "msg": "success",
    "data": "eyJhbGciOiJIUzI1NiJ9.eyJuYW1lIjoi5byg5peg5b-MIiwiaWQiOjIsInVzZXJuYW1lIjoiemhhbmd3dWppIiwiZXhwIjoxNzE2MTM5NjUyfQ.OeJnOCNg1f78FejZSfRn6_srJp8ZLre43jY9_9eD0D4"
}

6.2.3 过滤器 Filter

1. 快速入门

@WebFilter(urlPatterns = "/*")
public class DemoFilter implements Filter {
    @Override   // 初始化方法, 只调用一次
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("init 初始化方法执行了");
    }
    @Override   // 拦截到请求之后调用, 调用多次
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain){
        System.out.println("DemoFilter 拦截方法执行了");
        chain.doFilter(request,response);   // 放行
    }
    @Override   // 销毁方法, 只调用一次
    public void destroy() {
        System.out.println("destroy 销毁方法执行了");
    }
}
@ServletComponentScan // 开启了对 servlet 组件的支持
@SpringBootApplication
public class TliasWebManagementApplication {...}

2. Filter 详解

@WebFilter(urlPatterns = "/*")
public class DemoFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain){
        System.out.println("DemoFilter 拦截到了请求...放行前逻辑");
        chain.doFilter(request,response);
        System.out.println("DemoFilter 拦截到了请求...放行后逻辑");
    }
}
拦截路径 urlPatterns 值 含义
拦截具体路径 /login 只有访问 /login 路径时,才会被拦截
目录拦截 /emps/* 访问 /emps 下的所有资源,都会被拦截
拦截所有 /* 访问所有资源,都会被拦截
@WebFilter(urlPatterns = "/*")
public class AbcFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain){
        System.out.println("AbcFilter 拦截到了请求...放行前逻辑");
        chain.doFilter(request,response);
        System.out.println("AbcFilter 拦截到了请求...放行后逻辑");
    }
}
AbcFilter 拦截到了请求...放行前逻辑
DemoFilter 拦截到了请求...放行前逻辑
DemoFilter 拦截到了请求...放行后逻辑
AbcFilter 拦截到了请求...放行后逻辑

3. Filter 实现

@Component
public class LoginCheckFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;

        // 1.获取请求 url
        String url = req.getRequestURL().toString();
        // 2.判断请求 url 中是否包含 login, 如果包含, 说明是登录操作, 放行
        if(url.contains("login")){
            chain.doFilter(request,response);
            return;
        }
        // 3.获取请求头中的令牌 (token)
        String jwt = req.getHeader("token");
        // 4.判断令牌是否存在, 如果不存在, 返回错误结果 (未登录)
        if(!StringUtils.hasLength(jwt)){
            Result error = Result.error("NOT_LOGIN");
            String notLogin = JSONObject.toJSONString(error); //手动转换对象 -- json
            resp.getWriter().write(notLogin);
            return;
        }
        // 5.解析 token, 如果解析失败, 返回错误结果 (未登录)
        try {
            JwtUtils.parseJWT(jwt);
        } catch (Exception e) {
            e.printStackTrace();
            Result error = Result.error("NOT_LOGIN");
            String notLogin = JSONObject.toJSONString(error); // 手动转换对象 -- json
            resp.getWriter().write(notLogin);
            return;
        }
        // 6.放行
        chain.doFilter(request, response);
    }
}
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.76</version>
</dependency>

用户登录成功后,系统会自动下发 JWT 令牌,然后在后续的每次请求中,都需要在请求头 header 中携带到服务端,请求头的名称为 token ,值为 登录时下发的 JWT 令牌。

如果检测到用户未登录,则会返回固定错误信息。

//  postman: get: http://localhost:8080/depts
//  Headers: Key = token, value = eyJhbGciOiJIUzI1NiJ9.eyJuYW1lIjoi5byg5peg5b-MIiwiaWQiOjIsInVzZXJuYW1lIjoiemhhbmd3dWppIiwiZXhwIjoxNzE2MTM5NjUyfQ.OeJnOCNg1f78FejZSfRn6_srJp8ZLre43jY9_9eD0D4
{
    "code": 1,
    "msg": "success",
    "data": [...]
}
//  postman: get: http://localhost:8080/depts
//  Headers: Key = token, value = ABChbGciOiJIUzI1NiJ9.eyJuYW1lIjoi5byg5peg5b-MIiwiaWQiOjIsInVzZXJuYW1lIjoiemhhbmd3dWppIiwiZXhwIjoxNzE2MTM5NjUyfQ.OeJnOCNg1f78FejZSfRn6_srJp8ZLre43jY9_9eD0D4
{
    "code": 0,
    "msg": "NOT_LOGIN",
    "data": null
}

6.2.4 拦截器 Interceptor

1. 快速入门

@Component      // 1. 定义拦截器
public class LoginCheckInterceptor implements HandlerInterceptor {
    @Override   // 目标资源方法运行前运行, 返回 true 放行, 放回 false 不放行
    public boolean preHandle(HttpServletRequest req, HttpServletResponse resp, Object handler) {
        return true;
    }

    @Override   // 目标资源方法运行后运行
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
        System.out.println("postHandle ...");
    }

    @Override   // 视图渲染完毕后运行, 最后运行
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        System.out.println("afterCompletion...");
    }
}
@Configuration  // 2. 注册拦截器
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private LoginCheckInterceptor loginCheckInterceptor;
    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginCheckInterceptor).addPathPatterns("/**");
    }
}

2. Interceptor 详解

拦截路径 含义 举例
/* 一级路径 能匹配 /depts,/emps,/login,不能匹配 /depts/1
/** 任意级路径 能匹配 /depts,/depts/1,/depts/1/2
/depts/* /depts 下的一级路径 能匹配 /depts/1,不能匹配 /depts/1/2,/depts
/depts/** /depts 下的任意级路径 能匹配 /depts,/depts/1,/depts/1/2,不能匹配 /emps/1
@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(loginCheckInterceptor).addPathPatterns("/**").excludePathPatterns("/login");
}

3. Interceptor 实现

@Override
public boolean preHandle(HttpServletRequest req, HttpServletResponse resp, Object handler) {
    ...     // 同 Filter 接口, 放行返回 true, 不放行放回 false
}
//  postman: get: http://localhost:8080/depts
{
    "code": 0,
    "msg": "NOT_LOGIN",
    "data": null
}
//  postman: get: http://localhost:8080/depts
//  Headers: Key = token, value = xyJhbGciOiJIUzI1NiJ9.eyJuYW1lIjoi5byg5peg5b-MIiwiaWQiOjIsInVzZXJuYW1lIjoiemhhbmd3dWppIiwiZXhwIjoxNzE2MTM5NjUyfQ.OeJnOCNg1f78FejZSfRn6_srJp8ZLre43jY9_9eD0D4
{
    "code": 1,
    "msg": "success",
    "data": [...]
}

7 异常处理

程序开发过程中不可避免的会遇到异常现象,出现异常时,默认返回的结果不符合规范

  1. 在 Controller 的方法中进行 try…catch 处理(代码臃肿,不推荐)
  2. 全局异常处理器(简单、优雅,推荐)
@RestControllerAdvice   // = @ControllerAdvice + @ResponseBody
public class GlobalExceptionHandler {
    @ExceptionHandler(Exception.class)  // 捕获所有异常
    public Result ex(Exception ex){
        ex.printStackTrace();
        return Result.error("对不起,操作失败,请联系管理员");
    }
}

参考链接:https://www.bilibili.com/video/BV1m84y1w7Tb?p=135&vd_source=ed621eaa6bcf9bf6acb7d0527c30489a

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