public abstract classAbstractObject{ //操作 public abstract void operation();}publicclassRealObject extends AbstractObject{ @Override publicvoid operation(){ //一些操作 System.out.println("一些操作"); }}publicclassProxyObject extends AbstractObject{ RealObject realObject =newRealObject(); @Override publicvoid operation(){ //调用目标对象之前可以做相关操作 System.out.println("before"); realObject.operation(); //调用目标对象之后可以做相关操作 System.out.println("after"); }}publicclassClient{ publicstaticvoid main(String[] args){ AbstractObject obj =newProxyObject(); obj.operation(); }}
publicclassProxyImage implements Image{ privateRealImage realImage; privateString fileName; publicProxyImage(String fileName){ this.fileName = fileName; } @Override publicvoid display(){ if(realImage == null){ realImage =newRealImage(fileName); } realImage.display(); }}原文：http://www.cnblogs.com/Doing-what-I-love/p/5621171.html