springboot项目案例

以下是一个简单的Spring Boot项目案例，它可以实现用户的增删改查功能：

1. 创建一个Spring Boot项目，可以使用Spring Initializr或者直接手动创建项目。

2. 在pom.xml文件中添加以下依赖：

<dependencies>
    <!-- Spring Boot Web依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- Spring Boot JDBC依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

    <!-- MySQL数据库驱动依赖 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>

    <!-- Spring Boot Test依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

3. 创建一个用户实体类User.java：

public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;

    // getters and setters
}

4. 创建一个用户数据访问对象UserDAO.java：

@Repository
public class UserDAO {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public List<User> findAll() {
        List<User> users = jdbcTemplate.query("select * from user", new BeanPropertyRowMapper<>(User.class));
        return users;
    }

    public User findById(Long id) {
        User user = jdbcTemplate.queryForObject("select * from user where id=?", new Object[]{id}, new BeanPropertyRowMapper<>(User.class));
        return user;
    }

    public int insert(User user) {
        int count = jdbcTemplate.update("insert into user(name, age, email) values(?, ?, ?)", user.getName(), user.getAge(), user.getEmail());
        return count;
    }

    public int update(User user) {
        int count = jdbcTemplate.update("update user set name=?, age=?, email=? where id=?", user.getName(), user.getAge(), user.getEmail(), user.getId());
        return count;
    }

    public int deleteById(Long id) {
        int count = jdbcTemplate.update("delete from user where id=?", id);
        return count;
    }
}

5. 创建一个用户控制器类UserController.java：

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserDAO userDAO;

    @GetMapping
    public List<User> findAll() {
        return userDAO.findAll();
    }

    @GetMapping("/{id}")
    public User findById(@PathVariable Long id) {
        return userDAO.findById(id);
    }

    @PostMapping
    public int insert(@RequestBody User user) {
        return userDAO.insert(user);
    }

    @PutMapping("/{id}")
    public int update(@PathVariable Long id, @RequestBody User user) {
        user.setId(id);
        return userDAO.update(user);
    }

    @DeleteMapping("/{id}")
    public int deleteById(@PathVariable Long id) {
        return userDAO.deleteById(id);
    }
}

6. 运行项目，访问http://localhost:8080/user即可查看所有用户信息，也可以使用POST、PUT、DELETE请求来增加、修改、删除用户信息。