aspectj為類(lèi)和對(duì)象的構(gòu)造和初始化中每個(gè)階段都提供了切入點(diǎn)

捕獲對(duì)構(gòu)造函數(shù)的調(diào)用

形式:call(ConstructorPattern)

定義:Picks out each constructor call join point whose signature matches ConstructorPattern.

demo

package aspectj;

public class MyClass {
    public void b() {
        System.out.println("call b");
    }

    MyClass(int x) {

    }
    public static void main(String[] args) {
        MyClass myClass = new MyClass(3);
        myClass.b();
    }
}


package aspectj;

public aspect HelloWorld {
    //具有new關(guān)鍵字的切入點(diǎn)會(huì)捕獲joinPoint,帶上必要的參數(shù)
    pointcut callPointcut():call(MyClass.new(int));

    before(): callPointcut()
    {
        System.out.println("hello");
        System.out.println(thisJoinPoint.getSignature());
        System.out.println(thisJoinPoint.getSourceLocation());
    }
}

輸出

hello
aspectj.MyClass(int)
MyClass.java:12
call b

調(diào)用順序，參考

捕獲構(gòu)造函數(shù)的調(diào)用

在執(zhí)行構(gòu)造函數(shù)時(shí)捕獲它

形式:execution(ConstructorPattern)

定義:Picks out each constructor execution join point whose signature matches ConstructorPattern.

demo

package aspectj;

public aspect HelloWorld {
    //具有new關(guān)鍵字的切入點(diǎn)會(huì)捕獲joinPoint,帶上必要的參數(shù)
    pointcut callPointcut():execution(MyClass.new(int));

    before(): callPointcut()
    {
        System.out.println("hello");
        System.out.println(thisJoinPoint.getSignature());
        System.out.println(thisJoinPoint.getSourceLocation());
    }
}

輸出

hello
aspectj.MyClass(int)
MyClass.java:8
call b

調(diào)用順序參考

捕獲構(gòu)造函數(shù)的執(zhí)行

捕獲何時(shí)初始化對(duì)象

形式:initialization(ConstructorPattern)

定義:Picks out each object initialization join point whose signature matches ConstructorPattern.

initialization捕捉對(duì)象初始化

demo在后面一起寫(xiě)

捕獲何時(shí)將要初始化對(duì)象

形式:preinitialization(ConstructorPattern)

定義:Picks out each object pre-initialization join point whose signature matches ConstructorPattern.

通過(guò)下圖來(lái)區(qū)分preinitialization以及initialization，也可以參照后面demo

preinitialization捕捉何時(shí)將要初始化對(duì)象

捕獲何時(shí)初始化類(lèi)

staticinitialization(TypePattern)
Picks out each static initializer execution join point whose signature matches TypePattern.

staticinitialization捕捉類(lèi)的初始化

下面一起列出demo

package aspectj;

public class MyClass extends SuperClass{
    static {
        System.out.println("MyClass.static");
    }
    MyClass(int x) {
        super(x);
    }

    public static void main(String[] args) {
        MyClass myClass = new MyClass(3);
    }
}



package aspectj;

public class SuperClass {
    static {
        System.out.println("SuperClass.static");
    }
    SuperClass(int x){}
}



package aspectj;

public aspect HelloWorld {

    pointcut callPointcut():execution(SuperClass+.new(int));

    before(): callPointcut()
    {
        System.out.println("execution");
        System.out.println(thisJoinPoint.getSourceLocation());
    }

    pointcut initializationPointcut():initialization(SuperClass+.new(int));

    before(): initializationPointcut()
    {
        System.out.println("initialization");
        System.out.println(thisJoinPoint.getSourceLocation());
    }

    pointcut preInitPointcut():preinitialization(SuperClass+.new(int));

    before(): preInitPointcut()
    {
        System.out.println("preinitialization");
        System.out.println(thisJoinPoint.getSourceLocation());
    }

    pointcut staticInitPointcut():staticinitialization(SuperClass+);

    before(): staticInitPointcut()
            {
                System.out.println("staticinitialization");
                System.out.println(thisJoinPoint.getSourceLocation());
            }
}

輸出

staticinitialization
SuperClass.java:5
SuperClass.static
staticinitialization
MyClass.java:5
MyClass.static
preinitialization
MyClass.java:7
preinitialization
SuperClass.java:7
initialization
SuperClass.java:7
execution
SuperClass.java:7
initialization
MyClass.java:7
execution
MyClass.java:7

這里注意staticinitialization,initialization,preinitialization調(diào)用順序即可
雖然輸出的thisJoinPoint.getSourceLocation()結(jié)果是一樣碾盟，但是順序不一樣

備注

ConstructorPattern = 
  [ModifiersPattern ] 
        [TypePattern . ] new (TypePattern | ".." , ...) 
        [ throws ThrowsPattern ]

refer

http://itfish.net/article/50191.html
https://eclipse.org/aspectj/doc/released/progguide/semantics-pointcuts.html
《aspectj cookbook》