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2019.10.17??????????????????????????

??????????????Java????????

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class Base {    int i = 99;    public static Base cloneX(int s) {        Super a = new Super();        System.out.println("Base, clone " + s);        return a;    }    Base() {        System.out.println("Create Base with " + i);    }}class Super extends Base {    int i = 1000;    public static void main(String[] args) {        Super super1 = (Super) cloneX(5);        System.out.println("i is " + super1.i);    }}

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??SQL????????????????????????????????????????

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???????????????????????????????DFS?????????BFS??????????????????????????

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  ?Component?????????Decorator???Component????????????????????

  interface Component {    void doSomething();}class Decorator implements Component {    Component component;    public Decorator(Component component) {        this.component = component;    }    public void doSomething() {        component.doSomething();        // ??????        System.out.println("Decorator???????");    }}class ConcreteDecorator extends Decorator {    public ConcreteDecorator(Component component) {        super(component);    }    public void doSomething() {        component.doSomething();        System.out.println("ConcreteDecorator???????");    }}

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  interface Target {    void operate(Object obj);}class Adapter implements Target {    Source source;    public Adapter(Source source) {        this.source = source;    }    public void operate(Object obj) {        source.doSomething(obj);    }}

  ???Adapter???Source????????Target???????????????