MySQL使用版本号实现乐观锁

原创转载请注明出处：https://www.cnblogs.com/agilestyle/p/11608581.html

乐观锁适用于读多写少的应用场景 

乐观锁Version图示

Project Directory

Maven Dependency

 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>

     <groupId>HelloSpring</groupId>
     <artifactId>org.fool.spring</artifactId>
     <version>1.0-SNAPSHOT</version>

     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.5.22.RELEASE</version>
     </parent>

     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
             <exclusions>
                 <exclusion>
                     <groupId>org.springframework.boot</groupId>
                     <artifactId>spring-boot-starter-tomcat</artifactId>
                 </exclusion>
             </exclusions>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-jetty</artifactId>
             <exclusions>
                 <exclusion>
                     <groupId>org.eclipse.jetty.websocket</groupId>
                     <artifactId>websocket-server</artifactId>
                 </exclusion>
                 <exclusion>
                     <groupId>org.eclipse.jetty.websocket</groupId>
                     <artifactId>javax-websocket-server-impl</artifactId>
                 </exclusion>
             </exclusions>
         </dependency>

         <dependency>
             <groupId>org.mybatis.spring.boot</groupId>
             <artifactId>mybatis-spring-boot-starter</artifactId>
             <version>1.3.5</version>
         </dependency>

         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>druid-spring-boot-starter</artifactId>
             <version>1.1.20</version>
         </dependency>

         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
         </dependency>

         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>

         <dependency>
             <groupId>org.mybatis.generator</groupId>
             <artifactId>mybatis-generator-core</artifactId>
             <version>1.3.7</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

     <build>
         <plugins>
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
             </plugin>
             <plugin>
                 <groupId>org.mybatis.generator</groupId>
                 <artifactId>mybatis-generator-maven-plugin</artifactId>
                 <version>1.3.7</version>
                 <configuration>
                     <configurationFile>sql/generatorConfig.xml</configurationFile>
                     <verbose>true</verbose>
                     <overwrite>true</overwrite>
                 </configuration>
             </plugin>
         </plugins>
     </build>
 </project>

application.properties

 server.port=

 spring.datasource.url=jdbc:mysql://localhost:3306/test
 spring.datasource.username=root
 spring.datasource.password=
 spring.datasource.driver-class-name=com.mysql.jdbc.Driver

 mybatis.type-aliases-package=org.fool.spring.model
 mybatis.mapper-locations=classpath:mapper/**/*.xml

ddl.sql

 CREATE TABLE `goods` (
   `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
   `name` varchar(32) NOT NULL COMMENT '商品名称',
   `state` tinyint(4) unsigned NOT NULL COMMENT '1.正常；2.缺货',
   `version` bigint(20) unsigned NOT NULL,
   `create_time` timestamp(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
   `update_time` timestamp(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
   PRIMARY KEY (`id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

 insert into goods(name, state, version) values('iPhone', 1, 1);
 insert into goods(name, state, version) values('iMac', 1, 1);
 insert into goods(name, state, version) values('iPad', 1, 1);
 insert into goods(name, state, version) values('iWatch', 1, 1);

generatorConfig.xml

 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE generatorConfiguration
         PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
         "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
 <generatorConfiguration>
     <classPathEntry
             location="/Users/${user.name}/.m2/repository/mysql/mysql-connector-java/5.1.48/mysql-connector-java-5.1.48.jar"/>

     <context id="test" targetRuntime="MyBatis3">

         <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
         <plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin"/>

         <commentGenerator>
             <property name="suppressAllComments" value="true"/>
         </commentGenerator>

         <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                         connectionURL="jdbc:mysql://localhost:3306/test"
                         userId="root"
                         password="123456">
         </jdbcConnection>

         <javaModelGenerator targetPackage="org.fool.spring.model" targetProject="src/main/java">
             <property name="enableSubPackages" value="true"/>
             <property name="trimStrings" value="true"/>
         </javaModelGenerator>

         <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
             <property name="enableSubPackages" value="true"/>
         </sqlMapGenerator>

         <javaClientGenerator targetPackage="org.fool.spring.dao.mapper" targetProject="src/main/java"
                              type="XMLMAPPER">
             <property name="enableSubPackages" value="true"/>
         </javaClientGenerator>

         <table tableName="goods" domainObjectName="Goods"
                enableCountByExample="false" enableUpdateByExample="false"
                enableDeleteByExample="false" enableSelectByExample="false"
                selectByExampleQueryId="false">
         </table>

     </context>

 </generatorConfiguration>

自动生成model和mapper

 mybatis-generator:generate -e

Goods.java

 package org.fool.spring.model;

 import java.util.Date;

 public class Goods {
     private Long id;

     private String name;

     private Byte state;

     private Long version;

     private Date createTime;

     private Date updateTime;

     public Long getId() {
         return id;
     }

     public void setId(Long id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name == null ? null : name.trim();
     }

     public Byte getState() {
         return state;
     }

     public void setState(Byte state) {
         this.state = state;
     }

     public Long getVersion() {
         return version;
     }

     public void setVersion(Long version) {
         this.version = version;
     }

     public Date getCreateTime() {
         return createTime;
     }

     public void setCreateTime(Date createTime) {
         this.createTime = createTime;
     }

     public Date getUpdateTime() {
         return updateTime;
     }

     public void setUpdateTime(Date updateTime) {
         this.updateTime = updateTime;
     }

     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append(getClass().getSimpleName());
         sb.append(" [");
         sb.append("Hash = ").append(hashCode());
         sb.append(", id=").append(id);
         sb.append(", name=").append(name);
         sb.append(", state=").append(state);
         sb.append(", version=").append(version);
         sb.append(", createTime=").append(createTime);
         sb.append(", updateTime=").append(updateTime);
         sb.append("]");
         return sb.toString();
     }
 }

GoodsMapper.java

 package org.fool.spring.dao.mapper;

 import org.fool.spring.model.Goods;

 public interface GoodsMapper {
     int deleteByPrimaryKey(Long id);

     int insert(Goods record);

     int insertSelective(Goods record);

     Goods selectByPrimaryKey(Long id);

     int updateByPrimaryKeySelective(Goods record);

     int updateByPrimaryKey(Goods record);
 }

GoodsMapper.xml

 <?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="org.fool.spring.dao.mapper.GoodsMapper">
   <resultMap id="BaseResultMap" type="org.fool.spring.model.Goods">
     <id column="id" jdbcType="BIGINT" property="id" />
     <result column="name" jdbcType="VARCHAR" property="name" />
     <result column="state" jdbcType="TINYINT" property="state" />
     <result column="version" jdbcType="BIGINT" property="version" />
     <result column="create_time" jdbcType="TIMESTAMP" property="createTime" />
     <result column="update_time" jdbcType="TIMESTAMP" property="updateTime" />
   </resultMap>
   <sql id="Base_Column_List">
     id, name, state, version, create_time, update_time
   </sql>
   <select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
     select
     <include refid="Base_Column_List" />
     from goods
     where id = #{id,jdbcType=BIGINT}
   </select>
   <delete id="deleteByPrimaryKey" parameterType="java.lang.Long">
     delete from goods
     where id = #{id,jdbcType=BIGINT}
   </delete>
   <insert id="insert" parameterType="org.fool.spring.model.Goods">
     insert into goods (id, name, state,
       version, create_time, update_time
       )
     values (#{id,jdbcType=BIGINT}, #{name,jdbcType=VARCHAR}, #{state,jdbcType=TINYINT},
       #{version,jdbcType=BIGINT}, #{createTime,jdbcType=TIMESTAMP}, #{updateTime,jdbcType=TIMESTAMP}
       )
   </insert>
   <insert id="insertSelective" parameterType="org.fool.spring.model.Goods">
     insert into goods
     <trim prefix="(" suffix=")" suffixOverrides=",">
       <if test="id != null">
         id,
       </if>
       <if test="name != null">
         name,
       </if>
       <if test="state != null">
         state,
       </if>
       <if test="version != null">
         version,
       </if>
       <if test="createTime != null">
         create_time,
       </if>
       <if test="updateTime != null">
         update_time,
       </if>
     </trim>
     <trim prefix="values (" suffix=")" suffixOverrides=",">
       <if test="id != null">
         #{id,jdbcType=BIGINT},
       </if>
       <if test="name != null">
         #{name,jdbcType=VARCHAR},
       </if>
       <if test="state != null">
         #{state,jdbcType=TINYINT},
       </if>
       <if test="version != null">
         #{version,jdbcType=BIGINT},
       </if>
       <if test="createTime != null">
         #{createTime,jdbcType=TIMESTAMP},
       </if>
       <if test="updateTime != null">
         #{updateTime,jdbcType=TIMESTAMP},
       </if>
     </trim>
   </insert>
   <update id="updateByPrimaryKeySelective" parameterType="org.fool.spring.model.Goods">
     update goods
     <set>
       <if test="name != null">
         name = #{name,jdbcType=VARCHAR},
       </if>
       <if test="state != null">
         state = #{state,jdbcType=TINYINT},
       </if>
       <if test="version != null">
         version = #{version,jdbcType=BIGINT},
       </if>
       <if test="createTime != null">
         create_time = #{createTime,jdbcType=TIMESTAMP},
       </if>
       <if test="updateTime != null">
         update_time = #{updateTime,jdbcType=TIMESTAMP},
       </if>
     </set>
     where id = #{id,jdbcType=BIGINT}
   </update>
   <update id="updateByPrimaryKey" parameterType="org.fool.spring.model.Goods">
     update goods
     set name = #{name,jdbcType=VARCHAR},
       state = #{state,jdbcType=TINYINT},
       version = #{version,jdbcType=BIGINT},
       create_time = #{createTime,jdbcType=TIMESTAMP},
       update_time = #{updateTime,jdbcType=TIMESTAMP}
     where id = #{id,jdbcType=BIGINT}
   </update>
 </mapper>

GoodsMapperExt.java

 package org.fool.spring.dao.mapper.extension;

 import org.fool.spring.model.Goods;

 public interface GoodsMapperExt {
     int casUpdateByPrimaryKey(Goods goods);
 }

GoodsMapperExt.xml

 <?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="org.fool.spring.dao.mapper.extension.GoodsMapperExt">
     <resultMap id="BaseResultMap" type="org.fool.spring.model.Goods">
         <id column="id" jdbcType="BIGINT" property="id"/>
         <result column="name" jdbcType="VARCHAR" property="name"/>
         <result column="state" jdbcType="TINYINT" property="state"/>
         <result column="version" jdbcType="BIGINT" property="version"/>
         <result column="create_time" jdbcType="TIMESTAMP" property="createTime"/>
         <result column="update_time" jdbcType="TIMESTAMP" property="updateTime"/>
     </resultMap>
     <sql id="Base_Column_List">
         id, name, state, version, create_time, update_time
     </sql>
     <update id="casUpdateByPrimaryKey" parameterType="org.fool.spring.model.Goods">
         update goods
         set name = #{name,jdbcType=VARCHAR},
         state = #{state,jdbcType=TINYINT},
         version = version + 1
         where id = #{id,jdbcType=BIGINT} and version = #{version,jdbcType=BIGINT}
     </update>
 </mapper>

Application.java

 package org.fool.spring;

 import org.mybatis.spring.annotation.MapperScan;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

 @SpringBootApplication
 @MapperScan("org.fool.spring.dao.mapper")
 public class Application {
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
 }

ApplicationTest.java

 package org.fool.spring.test;

 import org.fool.spring.Application;
 import org.fool.spring.dao.mapper.GoodsMapper;
 import org.fool.spring.dao.mapper.extension.GoodsMapperExt;
 import org.fool.spring.model.Goods;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.test.context.junit4.SpringRunner;

 @RunWith(SpringRunner.class)
 @SpringBootTest(classes = Application.class)
 @EnableAutoConfiguration
 public class ApplicationTest {
     @Autowired
     private GoodsMapper goodsMapper;

     @Autowired
     private GoodsMapperExt goodsMapperExt;

     @Test
     public void testSelect() {
         Goods result = goodsMapper.selectByPrimaryKey(1L);
         assert 1 == result.getId();
     }

     @Test
     public void testUpdate() {
         Goods goods1 = goodsMapper.selectByPrimaryKey(1L);
         Goods goods2 = goodsMapper.selectByPrimaryKey(1L);

         goods1.setName("iPhone");
         goods2.setName("iPhoneXR");

         int result1 = goodsMapperExt.casUpdateByPrimaryKey(goods1);
         assert 1 == result1;
         int result2 = goodsMapperExt.casUpdateByPrimaryKey(goods2);
         assert 0 == result2;
     }
 }