java實現Composite組合模式的實例代碼

//節點抽象父類
/**
 * 透明模式就是把組合使用的方法放到抽象類中，不管葉子對象還是數值對象都有相同的結構
 * 這樣做的好處就是葉子結點和樹枝結點對於外界沒有區別，他們具備完全一致的行為接口
 */
public abstract class ComponentTransparent {
 protected String name;

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

 //增加一個葉子構件或者樹枝構件
 public abstract void add(ComponentTransparent componentTransparent);

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

 //獲取分支下的所有葉子構件和樹枝構件
 public abstract void display(int depth);
}

//文件架節點實現子類
import java.util.ArrayList;

public class CompositeTransparent extends ComponentTransparent{

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

 //構建容器
 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) {
  //輸出樹形結構
  for (int i = 0;i<depth;++i){
   System.out.print("-");
  }
  System.out.println(this.name);

  //下級遍歷
  for(ComponentTransparent componentTransparent:this.componentTransparentsArraylist){
   componentTransparent.display(depth+1);
  }
 }
}

//葉子節點實現子類
public class LeafTransparent extends ComponentTransparent{
 public LeafTransparent(String name){
  super(name);
 }

 @Override
 public void add(ComponentTransparent componentTransparent) {
  //空實現，拋出"不支持請求"異常
  throw new UnsupportedOperationException();
 }

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

 @Override
 public void display(int depth) {
  //輸出樹形結構的葉子節點
  for (int i = 0;i<depth;++i){
   System.out.print("-");
  }
  System.out.println(this.name);
 }
}

//節點抽象父類
public abstract class ComponentSafty {
 protected String name;

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

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

//文件夾節點實現子類
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);
  }
 }
}

//葉子結點實現子類
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);
 }
}

//測試主類
public class Main {
 private static void transparent(){
  //創建根節點以及其子節點
  ComponentTransparent root = new CompositeTransparent("root");
  root.add(new LeafTransparent("Leaf A"));
  root.add(new LeafTransparent("Leaf B"));

  //創建第二層結點及其子節點
  ComponentTransparent branch = new CompositeTransparent("Composite X");
  branch.add(new LeafTransparent("Leaf XA"));
  branch.add(new LeafTransparent("Leaf XB"));
  root.add(branch);

  //創建第三層節點及其子結點
  ComponentTransparent branch2 = new CompositeTransparent("Composite XY");
  branch2.add(new LeafTransparent("Leaf XYA"));
  branch2.add(new LeafTransparent("Leaf XYB"));
  branch.add(branch2);

  //創建第二層結點
  root.add(new LeafTransparent("Leaf C"));

  //常見第二層節點並刪除
  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(){
//創建根節點以及其子節點
  CompositeSafty root = new CompositeSafty("root");
  root.add(new LeafSafty("Leaf A"));
  root.add(new LeafSafty("Leaf B"));

  //創建第二層結點及其子節點
  CompositeSafty branch = new CompositeSafty("Composite X");
  branch.add(new LeafSafty("Leaf XA"));
  branch.add(new LeafSafty("Leaf XB"));
  root.add(branch);

  //創建第三層節點及其子結點
  CompositeSafty branch2 = new CompositeSafty("Composite XY");
  branch2.add(new LeafSafty("Leaf XYA"));
  branch2.add(new LeafSafty("Leaf XYB"));
  branch.add(branch2);

  //創建第二層結點
  root.add(new LeafSafty("Leaf C"));

  //常見第二層節點並刪除
  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();
 }
}