Java中lambda表达式实现aop切面功能

// 缓存的声明
private final Map<String, ObjectFactory<?>> singletonFactories = new HashMap<>(16);

// lambda作为参数调用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)) {
                // 缓存中添加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;
    }
 
    // 重写接口
    @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;
    }
    // 实现接口
    @Override
    public void Demo() {
        System.out.println("I'm DemoSonOne, My name is " + name);
    }
}

public class DemoMain { // lambda表达式进行封装 public static DemoInterface wrap(final DemoInterface demoInterface){ return () -> { System.out.println("Demo方法要执行了"); demoInterface.Demo(); System.out.println("Demo方法要执行完了"); }; } 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表达式进行封装
    public static DemoInterface wrap(final DemoInterface demoInterface){
        return () -> {
            System.out.println("Demo方法要执行了");
            demoInterface.Demo();
            System.out.println("Demo方法要执行完了");
        };
    }
 
    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);
        // 经过lambda封装，得到接口类型
        DemoInterface wrapOne = wrap(demoSonOne);
        wrapOne.Demo();
        // 由接口类型转换为现实类类型
        DemoSonOne wrapOne1 = (DemoSonOne) wrapOne;
        Integer age = wrapOne1.getAge();
        System.out.println(age);
    }