Java中lambda表示式實現aop切面功能

// 快取的宣告
private final Map<String, ObjectFactory<?>> singletonFactories = new HashMap<>(16);

// lambda作為引數呼叫addSingletonFactory方法
this.addSingletonFactory(beanName, () -> {
    return this.getEarlyBeanReference(beanName, mbd, bean);
});
 
 
// addSingletonFactory方法
    protected void addSingletonFactory(String beanName, ObjectFactory<?> singletonFactory) {
        Assert.notNull(singletonFactory, "Singleton factory must not be null");
        synchronized(this.singletonObjects) {
            if (!this.singletonObjects.containsKey(beanName)) {
                // 快取中新增lambda
                this.singletonFactories.put(beanName, singletonFactory);
                this.earlySingletonObjects.remove(beanName);
                this.registeredSingletons.add(beanName);
            }
 
        }
    }

@FunctionalInterface
public interface DemoInterface {
    void Demo();
}

public class DemoSonOne implements DemoInterface{
    public DemoSonOne(Integer age) {
        this.age = age;
    }
 
    private Integer age;
 
    public Integer getAge() {
        return age;
    }
 
    // 重寫介面
    @Override
    public void Demo() {
        System.out.println("I'm DemoSonOne, My age is " + age);
    }
}

public class DemoSonTwo implements DemoInterface{
    public DemoSonTwo(String name) {
        this.name = name;
    }
 
    private String name;
 
    public String getName() {
        return name;
    }
    // 實現介面
    @Override
    public void Demo() {
        System.out.println("I'm DemoSonOne, My name is " + name);
    }
}

public class DemoMain { // lambda表示式進行封裝 public static DemoInterface wrap(final DemoInterface demoInterface){ return () -> { System.out.println("Demo方法要執行了"); demoInterface.Demo(); System.out.println("Demo方法要執行完了"); }; } public static void main(String[] args) { DemoSonOne demoSonOne = new DemoSonOne(18); DemoSonTwo demoSonTwo = new DemoSonTwo("haha"); demoSonOne.Demo(); System.out.println("-----------------------"); demoSonTwo.Demo(); System.out.println("-----------------------"); DemoInterface wrapOne = wrap(demoSonOne); DemoInterface wrapTwo = wrap(demoSonTwo); wrapOne.Demo(); System.out.println("-----------------------"); wrapTwo.Demo(); }}public class DemoMain {
 
    // lambda表示式進行封裝
    public static DemoInterface wrap(final DemoInterface demoInterface){
        return () -> {
            System.out.println("Demo方法要執行了");
            demoInterface.Demo();
            System.out.println("Demo方法要執行完了");
        };
    }
 
    public static void main(String[] args) {
        DemoSonOne demoSonOne = new DemoSonOne(18);
        DemoSonTwo demoSonTwo = new DemoSonTwo("haha");
        demoSonOne.Demo();
        System.out.println("-----------------------");
        demoSonTwo.Demo();
 
        System.out.println("-----------------------");
        DemoInterface wrapOne = wrap(demoSonOne);
        DemoInterface wrapTwo = wrap(demoSonTwo);
        wrapOne.Demo();
        System.out.println("-----------------------");
        wrapTwo.Demo();
 
    }
}

    public static void main(String[] args) {
        DemoSonOne demoSonOne = new DemoSonOne(18);
        // 經過lambda封裝，得到介面型別
        DemoInterface wrapOne = wrap(demoSonOne);
        wrapOne.Demo();
        // 由介面型別轉換為現實類型別
        DemoSonOne wrapOne1 = (DemoSonOne) wrapOne;
        Integer age = wrapOne1.getAge();
        System.out.println(age);
    }