1.lombok的使用

2.Spring-mybatis-增删改查准备工作

springboot-mybatis-quickstart/src/test/java/com/inmind/SpringbootMybatisQuickstartApplicationTests.java

@@ -6,21 +6,61 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 
+import java.sql.*;
+import java.util.ArrayList;
 import java.util.List;
 
-@SpringBootTest
+@SpringBootTest //该注解的作用，启动spring环境，所以也就有了IOC容器
 class SpringbootMybatisQuickstartApplicationTests {
 
     @Autowired//直接从IOC容器中获取UserMapper类型的对象
-    private UserMapper userMapper;
+    private UserMapper userMapper;//接口开发，多态
 
     @Test
     void contextLoads() {
         //使用mybatis框架查询所有用户的数据
         List<User> list = userMapper.list();
         list.stream().forEach(user -> {
+            System.out.println(user.getId());
             System.out.println(user);
         });
     }
 
+    @Test
+    void testJDBC() throws ClassNotFoundException, SQLException {
+        //1. 注册驱动
+        Class.forName("com.mysql.cj.jdbc.Driver");
+
+        //2. 获取连接对象
+        String url = "jdbc:mysql://localhost:3306/mybatis";
+        String username = "root";
+        String password = "1234";
+        Connection connection = DriverManager.getConnection(url, username, password);
+
+        //3. 获取执行SQL的对象Statement,执行SQL,返回结果
+        String sql = "select * from user";
+        Statement statement = connection.createStatement();
+        ResultSet resultSet = statement.executeQuery(sql);
+
+        //4. 封装结果数据
+        List<User> userList = new ArrayList<>();
+        while (resultSet.next()){
+            int id = resultSet.getInt("id");
+            String name = resultSet.getString("name");
+            int age = resultSet.getInt("age");
+            short gender = resultSet.getShort("gender");
+            String phone = resultSet.getString("phone");
+
+            User user = new User(id,name,age,gender,phone);
+            userList.add(user);
+        }
+
+        //5. 释放资源
+        statement.close();
+        connection.close();
+
+
+        userList.forEach(System.out::println);
+    }
+
 }