[Java知识库]实现spring全局aop事务下部分异常不回滚

一把再SpringBoot中拿aop做全局事务时候代码大致都是如下：

@SpringBootConfiguration
@EnableTransactionManagement
@EnableAspectJAutoProxy
@MapperScan("xxx.server.dao.mapper")
public class JdbcConfig {
    private static final String AOP_POINTCUT_EXPRESSION = "execution (* xxx.server.service.impl.*.*(..))";

    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean("datasourceTxAdvice")
    public TransactionInterceptor txAdvice(DataSourceTransactionManager transactionManager) {
        DefaultTransactionAttribute txAttrRequired = new DefaultTransactionAttribute();
        txAttrRequired.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

        DefaultTransactionAttribute txAttrRequiredReadonly = new DefaultTransactionAttribute();
        txAttrRequiredReadonly.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
        txAttrRequiredReadonly.setReadOnly(true);

        NameMatchTransactionAttributeSource source = new NameMatchTransactionAttributeSource();
        source.addTransactionalMethod("save*", txAttrRequired);
        source.addTransactionalMethod("delete*", txAttrRequired);
        source.addTransactionalMethod("update*", txAttrRequired);
        // ...
        source.addTransactionalMethod("*", txAttrRequiredReadonly);
        final TransactionInterceptor transactionInterceptor = new TransactionInterceptor();
        transactionInterceptor.setTransactionManager(transactionManager);
        transactionInterceptor.setTransactionAttributeSource(source);
        return transactionInterceptor;
    }

    @Bean
    public Advisor adviceAdvisor(
            @Qualifier("datasourceTxAdvice") TransactionInterceptor transactionInterceptor) {
        AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut();
        pointcut.setExpression(AOP_POINTCUT_EXPRESSION);
        return new DefaultPointcutAdvisor(pointcut, transactionInterceptor);
    }
}

这个配置的意思是只有service层的实现类中的方法会开启事务，且开启事务时候允许嵌套事务，save/delete/update开头的方法不是只读事务，剩下的方法都是只读事务。这里用的是默认的DefaultTransactionAttribute，这里边判断是不是要回滚的标志就是异常是不是RuntimeException或者Error。

具体代码如下：

public class DefaultTransactionAttribute extends DefaultTransactionDefinition implements TransactionAttribute {

    // 省略部分代码

	@Override
	public boolean rollbackOn(Throwable ex) {
		return (ex instanceof RuntimeException || ex instanceof Error);
	}

    // 省略部分代码

}

Spring中事务实现的核心代码再org.springframework.transaction.interceptor.TransactionAspectSupport#invokeWithinTransaction方法中。

这个TransactionAspectSupport类中方法最终会调用TransactionAttribute#rollbackOn方法来确定要不要回滚。

所以要想实现部分异常下的不回滚，实现关键也在这里。如下是我实现以后的代码：

// 自定义不回滚事务的异常类
public class NoRollbackException extends RuntimeException {

    public NoRollbackException() {
        super();
    }

    public NoRollbackException(String message) {
        super(message);
    }

    public NoRollbackException(String message, Throwable cause) {
        super(message, cause);
    }

    public NoRollbackException(Throwable cause) {
        super(cause);
    }
}


@SpringBootConfiguration
@EnableTransactionManagement
@EnableAspectJAutoProxy
@MapperScan("xxx.server.dao.mapper")
public class JdbcConfig {
    private static final String AOP_POINTCUT_EXPRESSION = "execution (* xxx.server.service.impl.*.*(..))";

    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean("datasourceTxAdvice")
    public TransactionInterceptor txAdvice(DataSourceTransactionManager transactionManager) {
        DefaultTransactionAttribute txAttrRequired = new CustomRuleBasedTransactionAttribute();
        txAttrRequired.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

        DefaultTransactionAttribute txAttrRequiredReadonly = new CustomRuleBasedTransactionAttribute();
        txAttrRequiredReadonly.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
        txAttrRequiredReadonly.setReadOnly(true);

        NameMatchTransactionAttributeSource source = new NameMatchTransactionAttributeSource();
        source.addTransactionalMethod("save*", txAttrRequired);
        source.addTransactionalMethod("delete*", txAttrRequired);
        source.addTransactionalMethod("update*", txAttrRequired);
        // ...
        source.addTransactionalMethod("*", txAttrRequiredReadonly);
        final TransactionInterceptor transactionInterceptor = new TransactionInterceptor();
        transactionInterceptor.setTransactionManager(transactionManager);
        transactionInterceptor.setTransactionAttributeSource(source);
        return transactionInterceptor;
    }

    @Bean
    public Advisor adviceAdvisor(
            @Qualifier("datasourceTxAdvice") TransactionInterceptor transactionInterceptor) {
        AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut();
        pointcut.setExpression(AOP_POINTCUT_EXPRESSION);
        return new DefaultPointcutAdvisor(pointcut, transactionInterceptor);
    }


    private static class CustomRuleBasedTransactionAttribute extends DefaultTransactionAttribute {

        @Override
        public boolean rollbackOn(Throwable ex) {
            return !(ex instanceof NoRollbackException) && super.rollbackOn(ex);
        }
    }
}

如上述代码自定义CustomRuleBasedTransactionAttribute类继承DefaultTransactionAttribute类，然后重写rollbackOn方法，其中异常是自定义的NoRollbackException的话就不需要回滚了，否则还是走以前的逻辑。然后在创建DefaultTransactionAttribute对象的地方创建CustomRuleBasedTransactionAttribute对象即可实现。