编程式事务

比眉伴天荒 2022-03-18 08:18 232阅读 0赞

在基本的 MyBatis 中,session 工厂可以使用 SqlSessionFactoryBuilder 来创建。而在 MyBatis-Spring 中,则使用 **SqlSessionFactoryBean** 来替代。

MyBatis 的 SqlSession 提供指定的方法来处理编程式的事务。 但是当使用 MyBatis-Spring 时, bean 将会使用 Spring 管理的 SqlSession 或映射器来注入。 那就是说 Spring 通常是处理 事务的。你 不 能 在 Spring 管 理 的 SqlSession上调用 SqlSession.commit() , SqlSession.rollback() 或 SqlSession.close() 方 法 。 如果这样做了,就会抛UnsupportedOperationException 异常。注意在使用注入的映射器时不能访问那些方法。

无论 JDBC 连接是否设置为自动提交, SqlSession 数据方法的执行或在 Spring 事务之外 任意调用映射器方法都将会自动被提交。

使用编程式事务需要用**PlatformTransactionManager**来实现……

应用：

pom文件如下：

<dependencies>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.mybatis.spring.boot</groupId>
    			<artifactId>mybatis-spring-boot-starter</artifactId>
    			<version>1.3.1</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>com.github.pagehelper</groupId>
    			<artifactId>pagehelper</artifactId>
    			<version>5.0.1</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-test</artifactId>
    			<scope>test</scope>
    		</dependency>
    	</dependencies>

配置**SqlSessionFactoryBean**

@Autowired
    	private  DataSource dataSource;
    	@Bean
    	public SqlSessionFactory getSqlSessionFactory(DataSource dataSource) throws Exception {
    		 SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
    		 sqlSessionFactoryBean.setDataSource(dataSource);
    		 return sqlSessionFactoryBean.getObject();
    	}

修改application.properties文件

server.port=8080
    
    spring.datasource.url=jdbc:mysql://localhost:3306/disaster?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&rewriteBatchedStatements=true
    spring.datasource.username=root
    spring.datasource.password=123456789
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    mybatis.config-location=classpath:mybatisConfig.xml

mybatisConfig.xml文件：

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE configuration
    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
    	<settings>
    		<setting name="logImpl" value="LOG4J2"/>
    		<setting name="lazyLoadingEnabled" value="true"/>
        	<setting name="aggressiveLazyLoading" value="false"/>
        	<setting name="lazyLoadTriggerMethods" value="" />
        	
    	</settings>
      
    	<plugins>
    		<plugin interceptor="com.github.pagehelper.PageInterceptor">
    			<property name="helperDialect" value="mysql"/>
    		</plugin>
    	</plugins>
    </configuration>

数据库文件：

CREATE TABLE `disaster`.`Untitled`  (
      `account_id` int(11) NOT NULL DEFAULT 0 COMMENT '用户主键',
      `role_id` int(11) NOT NULL DEFAULT 0 COMMENT '角色主键',
      PRIMARY KEY (`account_id`, `role_id`) USING BTREE,
      INDEX `FKrs2s3m3039h0xt8d5yhwbuyam`(`role_id`) USING BTREE
    ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '用户角色表' ROW_FORMAT = Compact;

Dao层：

@Mapper
    public interface TestDao {
    	
    	@Insert("INSERT INTO account_role VALUES(#{id1},#{id2})")
    	void insert(@Param("id1")int id1,@Param("id2")int id2);
    
    }

控制器层：

package com.example.demo;
    
    import java.util.List;
    import java.util.Map;
    
    import javax.activation.DataSource;
    
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.transaction.PlatformTransactionManager;
    import org.springframework.transaction.TransactionDefinition;
    import org.springframework.transaction.TransactionStatus;
    import org.springframework.transaction.annotation.Transactional;
    import org.springframework.transaction.support.DefaultTransactionDefinition;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    /* 
    * @author zzf 
    * @date 2019年2月20日 上午9:36:30 
    */
    @RestController
    public class TestController {
    	
    	@Autowired
    	TestDao testDao;
    	@Autowired
    	private PlatformTransactionManager txManager;
    	
    	@GetMapping("/c")
    	@Transactional
    	public void test2(){
    		testDao.insert(1, 100);
        	testDao.insert(2, 100);
        	testDao.insert(3, 100);
    	}
    	@GetMapping("/b")
    	public void test(){
    		DefaultTransactionDefinition def = new DefaultTransactionDefinition();  
    	    def.setIsolationLevel(TransactionDefinition.ISOLATION_READ_COMMITTED);  
    	    def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);  
    	    //事务状态类，通过PlatformTransactionManager的getTransaction方法根据事务定义获取；获取事务状态后，Spring根据传播行为来决定如何开启事务
    	    TransactionStatus status = txManager.getTransaction(def);  
    	    try {
    	    	testDao.insert(1, 1);
    	    	testDao.insert(1, 2);
    	    	testDao.insert(1, 3);
    	    	txManager.commit(status);
    	    }catch (Exception e) {
    			// TODO: handle exception
    	    	System.out.println(e.getMessage());
    	    	txManager.rollback(status);
    		}
    	}
    
    }

测试：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70][]

[http://localhost:8080/b][http_localhost_8080_b]

![20190220110512940.png][]

将代码改为：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 1][]

再次请求[http://localhost:8080/b][http_localhost_8080_b]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 2][]

说明异常回滚

测试@Transactional

[http://localhost:8080/c][http_localhost_8080_c]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 3][]

代码修改为：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 4][]

再次运行[http://localhost:8080/c][http_localhost_8080_c]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 5][]

OK~说明事务生效了

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[http://www.mybatis.cn/][http_www.mybatis.cn]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70]: /images/20220318/d291b6fd7c1c43d292f22e2c8bd4eefd.png
[http_localhost_8080_b]: http://localhost:8080/b
[20190220110512940.png]: /images/20220318/cde92dfa0729450682b88e29b6e43406.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 1]: /images/20220318/c093299609f64832a2b311732c3b9643.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 2]: /images/20220318/3e678885543c4aae843d499c46b3539c.png
[http_localhost_8080_c]: http://localhost:8080/c
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 3]: /images/20220318/dd209a7ac4854d5d84214adb23cde226.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 4]: /images/20220318/362c201f09234791955a7c24f899334f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NTk4MDEx_size_16_color_FFFFFF_t_70 5]: /images/20220318/b50176264ff2495ba86f4acd203302c1.png
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