second

pom.xml

@@ -72,11 +72,6 @@
             <scope>test</scope>
         </dependency>
 
-        <dependency>
-            <groupId>com.github.code-cxz</groupId>
-            <artifactId>custom-toolkit</artifactId>
-            <version>v1.0.0</version>
-        </dependency>
 
     </dependencies>
 

src/main/java/com/example/practice/controller/UserController.java

@@ -0,0 +1,30 @@
+package com.example.practice.controller;
+
+import com.example.practice.entity.User;
+import com.example.practice.mapper.UserMapper;
+import com.example.practice.mapper.UserMapperImpl;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+//@Controller         // UserController userController = new UserController(); userController对象放到SpringIOC容器中
+//@ResponseBody       // 把返回值打印到浏览器上
+
+@RestController     // @Controller + @ResponseBody
+@RequestMapping("/user")
+public class UserController {
+
+    private UserMapper userMapper = new UserMapperImpl();
+
+    @GetMapping("/selectAll")
+    public List<User> queryAll() {
+        List<User> users = userMapper.selectAll();
+        return users;
+    }
+
+
+}

src/main/java/com/example/practice/mapper/UserMapper.java

@@ -0,0 +1,20 @@
+package com.example.practice.mapper;
+
+import com.example.practice.entity.User;
+
+import java.util.List;
+
+public interface UserMapper {
+
+    List<User> selectAll();
+
+    User selectOne(Long id);
+
+    int insert(User user);
+
+    int update(User user);
+
+    int delete(Long id);
+
+}
+

src/main/java/com/example/practice/mapper/UserMapperImpl.java

@@ -0,0 +1,63 @@
+package com.example.practice.mapper;
+
+import com.example.practice.entity.User;
+import com.example.practice.utils.SqlSessionFactoryUtils;
+import org.apache.ibatis.session.SqlSession;
+
+import java.util.List;
+
+public class UserMapperImpl implements UserMapper {
+
+
+    @Override
+    public List<User> selectAll() {
+        // Mybatis动态代理机制
+        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession(); // 命名空间.sqlId
+        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
+        List<User> list = userMapper.selectAll();
+//        List<User> list = sqlSession.selectList("com.example.practice.mapper.UserMapper.selectAll");
+        return list;
+    }
+
+    @Override
+    public User selectOne(Long id) {
+        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession();
+        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
+        User user = userMapper.selectOne(id);
+//        User user = sqlSession.selectOne("com.example.practice.mapper.UserMapper.selectOne", 2);
+        return user;
+    }
+
+    @Override
+    public int insert(User user) {
+        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession();
+        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
+        int result = userMapper.insert(user);
+//        int result = sqlSession.insert("com.example.practice.mapper.UserMapper.insert", user);
+        if (result == 0) throw new RuntimeException("删除失败");
+        sqlSession.commit();
+        return result;
+    }
+
+    @Override
+    public int update(User user) {
+        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession();
+        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
+        int result = userMapper.update(user);
+//        int result = sqlSession.update("com.example.practice.mapper.UserMapper.update", user);
+        if (result == 0) throw new RuntimeException("删除失败");
+        sqlSession.commit();
+        return result;
+    }
+
+    @Override
+    public int delete(Long id) {
+        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession();
+        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
+        int result = userMapper.delete(id);
+//        int result = sqlSession.delete("com.example.practice.mapper.UserMapper.delete", 2);
+        if (result == 0) throw new RuntimeException("删除失败");
+        sqlSession.commit();
+        return result;
+    }
+}

src/main/java/com/example/practice/sqlsessionTest/SqlSessionTest.java

@@ -1,29 +1,38 @@
 package com.example.practice.sqlsessionTest;
 
 import com.example.practice.entity.User;
-import org.apache.ibatis.io.Resources;
+import com.example.practice.mapper.UserMapper;
-import org.apache.ibatis.session.SqlSession;
+import com.example.practice.mapper.UserMapperImpl;
-import org.apache.ibatis.session.SqlSessionFactory;
-import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.util.List;
 
 public class SqlSessionTest {
 
     public static void main(String[] args) throws IOException {
 
-        // 加载配置文件（转成字节流的形式）
-        String resourcePath = "mybatis-config.xml";
-        InputStream is = Resources.getResourceAsStream(resourcePath);
 
-        // SqlSessionFactoryBuilder负责创建SqlSessionFactory对象
+        UserMapper userMapper = new UserMapperImpl();
-        // SqlSessionFactory负责生产SqlSession对象
+        List<User> users = userMapper.selectAll();
-        // SqlSession对象是负责连接数据库, 每执行一条sql语句，就会创建或者连接池中获取一个对象
+        for (User user : users) {
-        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
+            System.out.println(user);
-        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
+        }
-        SqlSession sqlSession = sqlSessionFactory.openSession();
+
+//        User user = userMapper.selectOne(2L);
+//        System.out.println(user);
+//
+//        userMapper.delete(2L);
+//
+//
+//        User insertUser = new User();
+//        userMapper.insert(insertUser);
+//
+//
+//        User updateUser = new User();
+//        userMapper.update(updateUser);
+
+
+//        SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSession();
 
 //        List<User> list = sqlSession.selectList("fdsgfgd.selectList");
 //        for (User user : list) {

src/main/java/com/example/practice/utils/SqlSessionFactoryUtils.java

@@ -0,0 +1,43 @@
+package com.example.practice.utils;
+
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public class SqlSessionFactoryUtils {
+
+    private static SqlSessionFactory sqlSessionFactory;
+
+    // 初始化SqlSessionFactory对象，表示需要操作哪个数据库
+    static {
+        // 加载配置文件（转成字节流的形式）
+        String resourcePath = "mybatis-config.xml";
+        InputStream is = null;
+        try {
+            is = Resources.getResourceAsStream(resourcePath);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        // SqlSessionFactoryBuilder负责创建SqlSessionFactory对象
+        // SqlSessionFactory负责生产SqlSession对象
+        // SqlSession对象是负责连接数据库, 每执行一条sql语句，就会创建或者连接池中获取一个对象
+        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
+        sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
+    }
+
+
+    // 获取数据库连接对象
+    public static SqlSession getSqlSession() {
+        SqlSession sqlSession = sqlSessionFactory.openSession();
+        return sqlSession;
+    }
+
+
+
+
+}

src/main/resources/application.yml

@@ -0,0 +1,6 @@
+spring:
+  datasource:
+    driver-class-name: com.mysql.cj.jdbc.Driver
+    url: jdbc:mysql://localhost:3306/practice
+    username: root
+    password: 123456

src/main/resources/mapper/UserMapper.xml

@@ -2,8 +2,8 @@
 <!DOCTYPE mapper
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
-<mapper namespace="fdsgfgd">
+<mapper namespace="com.example.practice.mapper.UserMapper">
-    <select id="selectList" resultType="com.example.practice.entity.User">
+    <select id="selectAll" resultType="com.example.practice.entity.User">
         select * from user
     </select>
 

src/main/resources/mybatis-config.xml

@@ -1,28 +1,28 @@
-<?xml version="1.0" encoding="UTF-8" ?>
+<!--<?xml version="1.0" encoding="UTF-8" ?>-->
-<!DOCTYPE configuration
+<!--<!DOCTYPE configuration-->
-        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
+<!--        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"-->
-        "http://mybatis.org/dtd/mybatis-3-config.dtd">
+<!--        "http://mybatis.org/dtd/mybatis-3-config.dtd">-->
 
-<configuration>
+<!--<configuration>-->
 
-    <environments default="dev">
+<!--    <environments default="dev">-->
 
-        <environment id="dev">
+<!--        <environment id="dev">-->
-            <transactionManager type="JDBC"/>
+<!--            <transactionManager type="JDBC"/>-->
-            <dataSource type="POOLED">
+<!--            <dataSource type="POOLED">-->
-                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
+<!--                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>-->
-                <property name="url" value="jdbc:mysql://localhost:3306/practice"/>
+<!--                <property name="url" value="jdbc:mysql://localhost:3306/practice"/>-->
-                <property name="username" value="root"/>
+<!--                <property name="username" value="root"/>-->
-                <property name="password" value="123456"/>
+<!--                <property name="password" value="123456"/>-->
-            </dataSource>
+<!--            </dataSource>-->
-        </environment>
+<!--        </environment>-->
 
-    </environments>
+<!--    </environments>-->
 
-    <mappers>
+<!--    <mappers>-->
-        <mapper resource="mapper/UserMapper.xml"/>
+<!--        <mapper resource="mapper/UserMapper.xml"/>-->
-    </mappers>
+<!--    </mappers>-->
 
-</configuration>
+<!--</configuration>-->