如何结合jersey和mybatis

结合Jersey和MyBatis的步骤如下：

1. 在pom.xml中添加Jersey和MyBatis的依赖项：

<dependencies>
    <!-- Jersey -->
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-server</artifactId>
        <version>2.25.1</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet-core</artifactId>
        <version>2.25.1</version>
    </dependency>

    <!-- MyBatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.2</version>
    </dependency>

    <!-- Database Driver -->
    <dependency>
        <groupId>com.mysql.jdbc</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.11</version>
    </dependency>
</dependencies>

2. 创建一个MyBatis的配置文件，例如mybatis-config.xml：

<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mydatabase" />
                <property name="username" value="myusername" />
                <property name="password" value="mypassword" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/example/mybatis/mapper/MyMapper.xml" />
    </mappers>
</configuration>

3. 创建MyMapper.xml文件，该文件定义了MyBatis映射器的SQL语句：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mybatis.mapper.MyMapper">
    <select id="selectUserById" parameterType="int" resultType="com.example.mybatis.User">
        SELECT * FROM users WHERE id = #{id}
    </select>
</mapper>

4. 创建一个DAO接口，例如MyDAO.java：

public interface MyDAO {
    User selectUserById(int id);
}

5. 创建一个DAO实现类，例如MyDAOImpl.java：

public class MyDAOImpl implements MyDAO {
    private SqlSessionFactory sqlSessionFactory;

    public MyDAOImpl() {
        String resource = "com/example/mybatis/config/mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Override
    public User selectUserById(int id) {
        try (SqlSession session = sqlSessionFactory.openSession()) {
            MyMapper mapper = session.getMapper(MyMapper.class);
            return mapper.selectUserById(id);
        }
    }
}

6. 创建一个Jersey资源类，例如MyResource.java：

@Path("/users")
public class MyResource {
    private MyDAO dao;

    public MyResource() {
        dao = new MyDAOImpl();
    }

    @GET
    @Path("/{id}")
    @Produces(MediaType.APPLICATION_JSON)
    public User getUserById(@PathParam("id") int id) {
        return dao.selectUserById(id);
    }
}

7. 将Jersey资源类注册到Jersey应用程序中，例如MyApplication.java：

@ApplicationPath("/api")
public class MyApplication extends ResourceConfig {
    public MyApplication() {
        register(MyResource.class);
    }
}

8. 部署应用程序并启动服务器，然后访问http://localhost:8080/api/users/1将返回id为1的用户的JSON表示。