feat: 读写分离

pom.xml

@@ -28,10 +28,16 @@
             <artifactId>spring-boot-starter-aop</artifactId>
         </dependency>
         <!-- 实现对 MyBatis 的自动化配置 -->
+<!--        <dependency>-->
+<!--            <groupId>org.mybatis.spring.boot</groupId>-->
+<!--            <artifactId>mybatis-spring-boot-starter</artifactId>-->
+<!--            <version>2.1.1</version>-->
+<!--        </dependency>-->
+        <!-- 实现对 MyBatis Plus 的自动化配置 -->
         <dependency>
-            <groupId>org.mybatis.spring.boot</groupId>
-            <artifactId>mybatis-spring-boot-starter</artifactId>
-            <version>2.1.1</version>
+            <groupId>com.baomidou</groupId>
+            <artifactId>mybatis-plus-boot-starter</artifactId>
+            <version>3.2.0</version>
         </dependency>
 
         <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->

src/main/java/com/yupi/project/mapper/OrderMapper.java

@@ -1,12 +1,13 @@
 package com.yupi.project.mapper;
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
 import com.yupi.project.model.entity.OrderDO;
 import org.apache.ibatis.annotations.Mapper;
 
 @Mapper
-public interface OrderMapper {
+public interface OrderMapper extends BaseMapper<OrderDO> {
 
 
 
-    void insert(OrderDO order);
+//    void insert(OrderDO order);
 
 }

src/main/java/com/yupi/project/model/entity/OrderDO.java

@@ -1,6 +1,8 @@
 package com.yupi.project.model.entity;
 
+import com.baomidou.mybatisplus.annotation.TableName;
 import lombok.Data;
+import lombok.experimental.Accessors;
 
 import java.io.Serializable;
 
@@ -9,6 +11,8 @@ import java.io.Serializable;
  * @author Administrator
  */
 @Data
+@TableName(value = "orders")
+@Accessors(chain = true)
 public class OrderDO implements Serializable {
 
     /**

src/main/java/com/yupi/project/service/OrderService.java

@@ -0,0 +1,36 @@
+package com.yupi.project.service;
+
+import com.yupi.project.mapper.OrderMapper;
+import com.yupi.project.model.entity.OrderDO;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+/**
+ * @author Administrator
+ */
+@Service
+public class OrderService {
+
+    @Autowired
+    private OrderMapper orderMapper;
+
+    @Transactional
+    public void add(OrderDO order) {
+        // <1.1> 这里先假模假样的读取一下。读取从库
+        OrderDO exists = orderMapper.selectById(1);
+        System.out.println(exists);
+
+        // <1.2> 插入订单
+        orderMapper.insert(order);
+
+        // <1.3> 这里先假模假样的读取一下。读取主库
+        exists = orderMapper.selectById(1);
+        System.out.println(exists);
+    }
+
+    public OrderDO findById(Integer id) {
+        return orderMapper.selectById(id);
+    }
+
+}

src/main/resources/application.yml

@@ -35,6 +35,11 @@ spring:
             inline:
               sharding-column: user_id
               algorithm-expression: orders_${user_id % 8}
+    # 读写分离配置，对应 YamlMasterSlaveRuleConfiguration 配置类
+    masterslave:
+      name: ms # 名字，任意，需要保证唯一
+      master-data-source-name: db0 # 主库数据源
+      slave-data-source-names: db1 # 从库数据源
     # 拓展属性配置
     props:
       sql:
@@ -43,6 +48,14 @@ server:
   port: 7529
   servlet:
     context-path: /api
-mybatis:
-  mapper-locations: classpath*:src/main/resources/mapper/*.xml
-  type-aliases-package: com.yupi.project.model.entity
+# mybatis-plus 配置内容
+mybatis-plus:
+  configuration:
+    map-underscore-to-camel-case: true # 虽然默认为 true ，但是还是显示去指定下。
+  global-config:
+    db-config:
+      id-type: none # 虽然 MyBatis Plus 也提供 ID 生成策略，但是还是使用 Sharding-JDBC 的
+      logic-delete-value: 1 # 逻辑已删除值(默认为 1)
+      logic-not-delete-value: 0 # 逻辑未删除值(默认为 0)
+  mapper-locations: classpath*:mapper/*.xml
+  type-aliases-package: com.yupi.project.model.entity

src/test/java/com/yupi/project/service/OrderMapperTest.java

@@ -2,6 +2,7 @@ package com.yupi.project.service;
 
 import com.yupi.project.mapper.OrderMapper;
 import com.yupi.project.model.entity.OrderDO;
+import org.apache.shardingsphere.api.hint.HintManager;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -15,14 +16,39 @@ public class OrderMapperTest {
 
     @Autowired
     private OrderMapper orderMapper;
+    @Autowired
+    private OrderService orderService;
+
+    @Test
+    public void testSelectById() { // 测试从库的负载均衡
+        for (int i = 0; i < 2; i++) {
+            OrderDO order = orderMapper.selectById(1);
+            System.out.println(order);
+        }
+    }
+
+    @Test
+    public void testSelectById02() { // 测试强制访问主库
+        try (HintManager hintManager = HintManager.getInstance()) {
+            // 设置强制访问主库
+            hintManager.setMasterRouteOnly();
+            // 执行查询
+            OrderDO order = orderMapper.selectById(1);
+            System.out.println(order);
+        }
+    }
 
 
     @Test
     public void testInsert() {
         OrderDO order = new OrderDO();
-        order.setId(2L);
-        order.setUserId(4);
+        order.setUserId(3);
         orderMapper.insert(order);
     }
 
+    @Test
+    public void testGroup() {
+        orderService.add(new OrderDO().setUserId(10));
+    }
+
 }