以下是一个基于Spring Boot的简单Java Web入门案例的步骤和代码示例:
- 创建Maven项目并添加依赖:
 
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.4</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>- 配置application.properties:
 
spring.datasource.url=jdbc:mysql://localhost:3306/your_database?useSSL=false
spring.datasource.username=root
spring.datasource.password=yourpassword
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
 
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.yourpackage.model- 创建实体类和Mapper接口:
 
// 实体类 User.java
public class User {
    private Integer id;
    private String name;
    // getters and setters
}
 
// Mapper 接口 UserMapper.java
@Mapper
public interface UserMapper {
    User selectUserById(Integer id);
}- 创建Service和Controller:
 
// Service 类 UserService.java
@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
 
    public User getUserById(Integer id) {
        return userMapper.selectUserById(id);
    }
}
 
// Controller 类 UserController.java
@RestController
@RequestMapping("/users")
public class UserController {
    @Autowired
    private UserService userService;
 
    @GetMapping("/{id}")
    public User getUser(@PathVariable Integer id) {
        return userService.getUserById(id);
    }
}- 创建启动类:
 
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}- 使用Postman或浏览器测试API:
 
GET http://localhost:8080/users/1以上代码提供了一个简单的Java Web入门案例,包括了Maven项目管理、Spring Boot的使用、MyBatis的集成以及对MySQL的连接。通过这个案例,开发者可以学习如何构建一个基础的Web应用,并且熟悉如何使用Spring Boot进行Web开发。