事务注解@Transactional不起作用原因及解决办法

发表于 | 分类于 |

参考
https://blog.csdn.net/qq_20597727/article/details/84900994
https://www.cnblogs.com/chen-lhx/p/6956152.html

Transactional失效场景介绍

第一种

Transactional注解标注方法修饰符为非public时,注解不起作用.

1
2
3
4
5
6
7
8
9
10
@Component
public class TestServiceImpl {
    @Resource
    TestMapper testMapper;
    
    @Transactional
    void insertTestWrongModifier() {
        testMapper.insert(new Test(10,20,30));
    }
}

第二种

在@Transactional标注方法所在类中调用.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
@Component
public class TestServiceImpl implements TestService {
    @Resource
    TestMapper testMapper;

    @Transactional
    public void insertTestInnerInvoke() {
        //正常public修饰符的事务方法
        testMapper.insert(new Test(10,20,30));
    }

    public void testInnerInvoke(){
        //类内部调用@Transactional标注的方法。
        insertTestInnerInvoke();
    }
}

第三种

捕获了异常,但不能回滚事务.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
@Component
public class TestServiceImpl {
    @Resource
    TestMapper testMapper;
    
    @Transactional
    void insertTestWrongModifier() {
        try {
            int num = testMapper.insert(new Test(10,20,30));
            if (num > 0){
                throw new NeedToInterceptException("need intercept");
            }
        } catch (Exception e) {
            System.out.println("i catch exception");
        }
    }
}

解决办法

第一种

被@Transactional标注的方法必须是public才生效.

1
2
3
4
5
6
7
8
protected TransactionAttribute computeTransactionAttribute(Method method, Class<?> targetClass) {
   // Don't allow no-public methods as required.
   // 非public 方法,返回@Transactional信息一律是null
   if (allowPublicMethodsOnly() && !Modifier.isPublic(method.getModifiers())) {
      return null;
   }
   ...
}

第二种

要想在内部使用,使用非this调用.
因为事务管理是基于动态代理对象实现的,如果在类内部自己调用其方法,就不是动态代理对象了,而是使用的this对象,从而绕过了动态代理,使其无效.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
@Component
public class TestServiceImpl implements TestService {
    @Resource
    TestMapper testMapper;
	
	@Resource
    TestServiceImpl testServiceImpl;

    @Transactional
    public void insertTestInnerInvoke() {
        //正常public修饰符的事务方法
        testMapper.insert(new Test(10,20,30));
    }

    public void testInnerInvoke(){
        //类内部调用@Transactional标注的方法。
        testServiceImpl.insertTestInnerInvoke();
    }
}

第三种

在catch块中抛异常,或在catch块中增加TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();语句.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
@Component
public class TestServiceImpl {
    @Resource
    TestMapper testMapper;
    
    @Transactional
    void insertTestWrongModifier() {
        try {
            int num = testMapper.insert(new Test(10,20,30));
            if (num > 0){
                throw new NeedToInterceptException("need intercept");
            }
        } catch (Exception e) {
            System.out.println("i catch exception");
			throw new RuntimeException(); 
        }
    }
}

或

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
@Component
public class TestServiceImpl {
    @Resource
    TestMapper testMapper;
    
    @Transactional
    void insertTestWrongModifier() {
        try {
            int num = testMapper.insert(new Test(10,20,30));
            if (num > 0){
                throw new NeedToInterceptException("need intercept");
            }
        } catch (Exception e) {
            System.out.println("i catch exception");
			TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();
        }
    }
}