Android AspectJ 重复织入的问题

矫情吗；* 2023-10-10 11:46 35阅读 0赞

AspectJ是Android AOP三剑客之一，对于一些面向切面的需求，能提供很好的解决方案。  
但最近，在使用过程中，发现一个问题，对于切点的织入，不仅仅是当前类，当前类的子类也会被织入，从而导致重复织入的问题。

比如我们有一个基类BaseActivity

public class BaseActivity extends AppCompatActivity {
        
    
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
        
            return super.onCreateOptionsMenu(menu);
        }
    
        @Override
        public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        
            return super.onOptionsItemSelected(item);
        }
    }

有一个主页Activity，继承自BaseActivity

public class MainActivity extends BaseActivity {
        
    	@Override
        protected void onCreate(@androidx.annotation.Nullable Bundle savedInstanceState) {
        
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }
    
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
        
            getMenuInflater().inflate(R.menu.menu_home, menu);
            return true;
        }
    
        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
        
            if (item.getItemId() == R.id.option_normal_1) {
        
                Toast.makeText(MainActivity.this, "Normal1", Toast.LENGTH_SHORT).show();
                return true;
            }
            return super.onOptionsItemSelected(item);
        }
    }

接着，我们新建一个BaseActivity的切面

运行程序，点击菜单的时候，会发现日志会被调用两遍。

----- methodMyOnOptionsItemSelected -----
    ----- methodMyOnOptionsItemSelected -----

这和我们想要的效果是有偏差的，为此，我们打印下joinPoint有哪些参数

@Aspect
    public class CheckBackAspect {
        
        @Pointcut("execution(boolean com.heiko.myaspecttest2.BaseActivity.onOptionsItemSelected(..))")
        public void methodMyOnOptionsItemSelected() {
        
    
        }
    
        @Around("methodMyOnOptionsItemSelected()")
        public boolean aroundMyOnOptionsItemSelected(ProceedingJoinPoint joinPoint) throws Throwable {
        
            String kind = joinPoint.getKind();
            String declaringTypeName = joinPoint.getSignature().getDeclaringTypeName();
            String signatureName = joinPoint.getSignature().getName();
            String srouceFileName = joinPoint.getSourceLocation().getFileName();
            String sourceWithinType = joinPoint.getSourceLocation().getWithinType().getName();
            Object target = joinPoint.getTarget();
            Log.i("CheckBackAspect", "----- methodMyOnOptionsItemSelected -----");
            Log.i("CheckBackAspect", "kind:" + kind);
            Log.i("CheckBackAspect", "declaringTypeName:" + declaringTypeName);
            Log.i("CheckBackAspect", "signatureName:" + signatureName);
            Log.i("CheckBackAspect", "srouceFileName:" + srouceFileName);
            Log.i("CheckBackAspect", "sourceWithinType:" + sourceWithinType);
            Log.i("CheckBackAspect", "target:" + target);
            return (boolean) joinPoint.proceed();
        }
    }

点击菜单的时候，可以看到

----- methodMyOnOptionsItemSelected -----
    kind:method-execution
    declaringTypeName:com.heiko.myaspecttest2.MainActivity
    signatureName:onOptionsItemSelected
    srouceFileName:MainActivity.java
    sourceWithinType:com.heiko.myaspecttest2.MainActivity
    target:com.heiko.myaspecttest2.MainActivity@8f6cec4
    ----- methodMyOnOptionsItemSelected -----
    kind:method-execution
    declaringTypeName:com.heiko.myaspecttest2.BaseActivity
    signatureName:onOptionsItemSelected
    srouceFileName:BaseActivity.java
    sourceWithinType:com.heiko.myaspecttest2.BaseActivity
    target:com.heiko.myaspecttest2.MainActivity@8f6cec4

可以看到，我们可以通过`declaringTypeName`或`sourceWithinType`来判断一下，拦截掉不需要的切面执行。

@Aspect
    public class CheckBackAspect {
        
        @Pointcut("execution(boolean com.heiko.myaspecttest2.BaseActivity.onOptionsItemSelected(..))")
        public void methodMyOnOptionsItemSelected() {
        
    
        }
    
        @Around("methodMyOnOptionsItemSelected()")
        public boolean aroundMyOnOptionsItemSelected(ProceedingJoinPoint joinPoint) throws Throwable {
        
            String declaringTypeName = joinPoint.getSignature().getDeclaringTypeName();
            if ("com.heiko.myaspecttest2.BaseActivity".equals(declaringTypeName)) {
        
                Log.i("CheckBackAspect", "执行onOptionsItemSelected切面");
                //执行了BaseActivity的onOptionsItemSelected切面
                //这里可以进行相关业务逻辑...
                return (boolean) joinPoint.proceed();
            }else{
        
                //对其他子类的切面，不进行操作
                return (boolean) joinPoint.proceed();
            }
        }
    }

我们再来运行下程序，点击菜单，可以看到，只打印了如下日志

执行onOptionsItemSelected切面

至此，我们就解决了切面重复织入的问题了。