将对象组合成树形结构以表示“整体-部分”的层次结构。composite是的用户对单个对象和组合对象的使用具有一致性
这里写图片描述
组合模式关键定义了一个抽象类或者接口，既可以代表元素又可以代表部分整体，而客户端是针对该接口进行编程。因此，客户端不需要知道是元素还是部分整体，对其统一进行处理。
代码
Main
public class Main {
public static void main(String[] args) {
Component l1=new Left();
Component l2=new Left();
Component l3=new Left();
Component l4=new Left();
Component c1=new Composite();
Component c2=new Composite();
c1.add(l1);c1.add(l2);
c1.add(c2);
c2.add(l3);c2.add(l4);
c1.each();
}
}
abs:Component
public abstract class Component {
abstract public void operation();
abstract public void add(Component c);
abstract public void remove(Component c);
abstract public Component getChild(int i);
abstract public void each();
}
imp:Composite
public class Composite extends Component {
private ArrayList<Component> list=new ArrayList<Component>();
@Override
public void operation() {
System.out.println("this is composite");
}
@Override
public void add(Component c) {
this.list.add(c);
}
@Override
public void remove(Component c) {
this.list.remove(c);
}
@Override
public Component getChild(int i) {
return this.list.get(i);
}
public void each(){
System.out.println("this is composite");
for(int i=0;i<this.list.size();i++)
this.list.get(i).each();
}
}
imp:Left
public class Left extends Component {
@Override
public void operation() {
System.out.println("--this is left opertaion");
}
@Override
public void add(Component c) {
// TODO Auto-generated method stub
}
@Override
public void remove(Component c) {
// TODO Auto-generated method stub
}
@Override
public Component getChild(int i) {
return null;
}
@Override
public void each() {
System.out.println("==this is left,no child");
}
}
