JAVA Builder模式構建MAP/LIST的示例

咱們在構建一個MAP時，要不停的調用put,有時候看着以爲很麻煩，恰好，看了下builder模式，以爲這思路不錯，因而乎，照着用builder模式寫了一個構建MAP的示例，代碼以下:

import java.util.HashMap;
import java.util.Map;

public class MapBuilder<T> {
	
	public Builder<T> b;
	
	public MapBuilder(Builder<T> b){
		this.b = b;
	}
	
	public Map<String,T> map(){
		return b.map;
	}
	
	public T get(String key){
		return b.map.get(key);
	}

	public static class Builder<T>{
		
		public Map<String, T> map;
		
		public Builder(){
			map = new HashMap<String, T>();
		}
		
		public Builder<T> map(String key, T value){
			map.put(key, value);
			return this;
		}
		
		
		public MapBuilder<T> build(){
			return new MapBuilder<T>(this);
		}
	}
	
	public static void main(String[] args) {
		MapBuilder<String> build = new MapBuilder.Builder<String>().map("a", "b").build();
		System.out.println(build.get("a"));
	}
	
}

public class ListBuilder<T> {
	
	public Builder<T> b;
	
	public ListBuilder(Builder<T> b){
		this.b = b;
	}
	
	public List<T> list(){
		return b.list;
	}
	
	public T get(int index){
		return b.list.get(index);
	}

	public static class Builder<T>{
		
		public List<T> list;
		
		public Builder(){
			list = new ArrayList<T>();
		}
		
		public Builder<T> add(T value){
			list.add(value);
			return this;
		}
		
		
		public ListBuilder<T> build(){
			return new ListBuilder<T>(this);
		}
	}
	
	public static void main(String[] args) {
		ListBuilder<String> build = new ListBuilder.Builder<String>().add("a").add("b").build();
		System.out.println(build.get(0));
	}
	
}

 

 

 

代碼很簡單，甚至都不用特殊說明，但裏面的知識點仍是蠻多的，好比builder模式，好比泛型的使用。

你們能夠在項目中試用一下，能使代碼更加的簡潔漂亮！