java实现Composite组合模式的实例代码

//节点抽象父类
/**
 * 透明模式就是把组合使用的方法放到抽象类中，不管叶子对象还是数值对象都有相同的结构
 * 这样做的好处就是叶子结点和树枝结点对于外界没有区别，他们具备完全一致的行为接口
 */
public abstract class ComponentTransparent {
 protected String name;

 public ComponentTransparent(String name){
  this.name = name;
 }

 //增加一个叶子构件或者树枝构件
 public abstract void add(ComponentTransparent componentTransparent);

 //删除
 public abstract void remove(ComponentTransparent componentTransparent);

 //获取分支下的所有叶子构件和树枝构件
 public abstract void display(int depth);
}

//文件架节点实现子类
import java.util.ArrayList;

public class CompositeTransparent extends ComponentTransparent{

 public CompositeTransparent(String name){
  super(name);
 }

 //构建容器
 private ArrayList<ComponentTransparent> componentTransparentsArraylist= new ArrayList<>();

 @Override
 public void add(ComponentTransparent componentTransparent) {
  this.componentTransparentsArraylist.add(componentTransparent);
 }

 @Override
 public void remove(ComponentTransparent componentTransparent) {
  this.componentTransparentsArraylist.remove(componentTransparent);
 }

 @Override
 public void display(int depth) {
  //输出树形结构
  for (int i = 0;i<depth;++i){
   System.out.print("-");
  }
  System.out.println(this.name);

  //下级遍历
  for(ComponentTransparent componentTransparent:this.componentTransparentsArraylist){
   componentTransparent.display(depth+1);
  }
 }
}

//叶子节点实现子类
public class LeafTransparent extends ComponentTransparent{
 public LeafTransparent(String name){
  super(name);
 }

 @Override
 public void add(ComponentTransparent componentTransparent) {
  //空实现，抛出"不支持请求"异常
  throw new UnsupportedOperationException();
 }

 @Override
 public void remove(ComponentTransparent componentTransparent) {
  throw new UnsupportedOperationException();
 }

 @Override
 public void display(int depth) {
  //输出树形结构的叶子节点
  for (int i = 0;i<depth;++i){
   System.out.print("-");
  }
  System.out.println(this.name);
 }
}

//节点抽象父类
public abstract class ComponentSafty {
 protected String name;

 public ComponentSafty(String name){
  this.name = name;
 }

 //展示
 public abstract void display(int depth);
}

//文件夹节点实现子类
import java.util.ArrayList;

public class CompositeSafty extends ComponentSafty{
 public CompositeSafty(String name){
  super(name);
 }

 private ArrayList<ComponentSafty> componentSaftyArrayList = new ArrayList<>();

 public void add(ComponentSafty component){
  this.componentSaftyArrayList.add(component);
 }

 public void remove(ComponentSafty componentSafty){
  this.componentSaftyArrayList.remove(componentSafty);
 }

 @Override
 public void display(int depth) {
  for (int i=0;i<depth;++i){
   System.out.print("-");
  }

  System.out.println(this.name);

  for (ComponentSafty componentSafty : componentSaftyArrayList) {
   componentSafty.display(depth+1);
  }
 }
}

//叶子结点实现子类
public class LeafSafty extends ComponentSafty{

 public LeafSafty(String name){
  super(name);
 }

 @Override
 public void display(int depth) {
  for (int i=0;i<depth;++i){
   System.out.print("-");
  }

  System.out.println(this.name);
 }
}

//测试主类
public class Main {
 private static void transparent(){
  //创建根节点以及其子节点
  ComponentTransparent root = new CompositeTransparent("root");
  root.add(new LeafTransparent("Leaf A"));
  root.add(new LeafTransparent("Leaf B"));

  //创建第二层结点及其子节点
  ComponentTransparent branch = new CompositeTransparent("Composite X");
  branch.add(new LeafTransparent("Leaf XA"));
  branch.add(new LeafTransparent("Leaf XB"));
  root.add(branch);

  //创建第三层节点及其子结点
  ComponentTransparent branch2 = new CompositeTransparent("Composite XY");
  branch2.add(new LeafTransparent("Leaf XYA"));
  branch2.add(new LeafTransparent("Leaf XYB"));
  branch.add(branch2);

  //创建第二层结点
  root.add(new LeafTransparent("Leaf C"));

  //常见第二层节点并删除
  ComponentTransparent leaf = new LeafTransparent("Leaf D");
  root.add(leaf);
  root.display(1);
  root.remove(leaf);

  for(int i =0;i<10;++i){
   System.out.print("=");
  }
  System.out.println();
  //展示
  root.display(1);
 }

 private static void safty(){
//创建根节点以及其子节点
  CompositeSafty root = new CompositeSafty("root");
  root.add(new LeafSafty("Leaf A"));
  root.add(new LeafSafty("Leaf B"));

  //创建第二层结点及其子节点
  CompositeSafty branch = new CompositeSafty("Composite X");
  branch.add(new LeafSafty("Leaf XA"));
  branch.add(new LeafSafty("Leaf XB"));
  root.add(branch);

  //创建第三层节点及其子结点
  CompositeSafty branch2 = new CompositeSafty("Composite XY");
  branch2.add(new LeafSafty("Leaf XYA"));
  branch2.add(new LeafSafty("Leaf XYB"));
  branch.add(branch2);

  //创建第二层结点
  root.add(new LeafSafty("Leaf C"));

  //常见第二层节点并删除
  LeafSafty leaf = new LeafSafty("Leaf D");
  root.add(leaf);
  root.display(1);
  root.remove(leaf);

  for(int i =0;i<10;++i){
   System.out.print("=");
  }
  System.out.println();
  //展示
  root.display(1);
 }

 public static void main(String[] args) {
  System.out.println("透明模式：");
  transparent();
  for(int i =0;i<10;++i){
   System.out.print("=");
  }
  System.out.println();
  System.out.println("安全模式：");
  safty();
 }
}