Spring transaction method fails to call their own class solutions and the reason java proxy, proxy static and dynamic agents and spring aop agents, to achieve the principle of unified summary

problem

Under normal circumstances, we are all called in the controller in service in the method, which if need to add a transaction, you add @Transactional on the method, this is no problem, the transaction will take effect.

But if something like this around the following, service method calls the method in their own classes, this time even added @Transactional, the transaction will not take effect.

@Controller
public class TestController {
    
    @Autowired
    private TestService testService;
    
    @GetMapping("/test")
    public void test(){
        testService.methodB();
    }
    
}

@Service
 public  class the TestService { 

    @Transactional 
    public  void methodA () { 

    } 

    / ** 
     * called here methodA () will fail transaction 
     * / 
    public  void methodB () {
         the this .methodA (); 
    } 

}

the reason

Because, spring transaction is realized using a proxy class to implement, but this.methodA here (), and did not take TestService proxy class, so the transaction will fail.

solve

Method 1: The methodA () and methodB () are placed in a different class.

Method 2: themselves into their own, calling injected with examples

@Service
 public  class TestService { 

    @Autowired 
    Private TestService TestService; 
    
    the @Transactional 
    public  void methodA () { 

    } 

    / ** 
     * called here methodA () transaction will take effect 
     * / 
    public  void methodB () { 
        testService.methodA (); 
    } 

}

Method 3: Obtain the proxy class, call the method using the proxy class of their own class

@Service
 public  class TestService { 

    the @Transactional 
    public  void methodA () { 

    } 

    / ** 
     * called here methodA () transaction will take effect 
     * / 
    public  void methodB () {
         ((TestService) the AopContext.currentProxy ()). MethodA ( ); 
    } 

}

At last

The spring aop agents have jdk cglib agents and agent implementation, with specific reference to the java proxy, proxy static and dynamic spring aop agents and agents, to achieve the principle of unified summary

        // if the proxy object 
        AopUtils.isAopProxy (the AopContext.currentProxy ()); 

        // whether cglib proxy object 
        AopUtils.isCglibProxy (the AopContext.currentProxy ()); 

        // if jdk dynamic proxy 
        AopUtils.isJdkDynamicProxy (AopContext.currentProxy ());