Java Collections-1

「爱情、让人受尽委屈。」 2022-08-05 07:39 7阅读 0赞

看到一篇非常好的文章，不是非常理解，写一博客权当记录。

数组转成List，[参考][Link 1]

Collections 比数组好，与数组相比arrays具有性能优势，例如，若要将数组的内容转储到一个字符串，需要迭代整个数组，然后将内容连接成一个 String；而 Collections 的实现都有一个可用的 toString() 实现。

person类

package com.zz.bridge;
    
    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;
    
    
    public class Person implements Iterable<Person>{
    	
    	private String firstName;
    	private String lastName;
    	private int age;
    	private List<Person> children = new ArrayList<Person>();
    	
    	//可变长参数，就是这个位置可以传入 0～任意个该类型参数
    	public Person(String fn, String ln, int a, Person... kids){
            this.firstName = fn; 
            this.lastName = ln; 
            this.age = a;
            for (Person child : kids)
                 children.add(child);
            }
    	
    	public String getFirstName() { 
    		return this.firstName; 
    	}
    	
    	public String getLastName() { 
    		return this.lastName; 
    	}
    	
    	public int getAge() { 
    		return this.age; 
    	}
    
    	public Iterator<Person> iterator() { 
    		return children.iterator(); 
    	}
    
    	public void setFirstName(String value) { 
    		this.firstName = value; 
    	}
    	public void setLastName(String value) { 
    		this.lastName = value; 
    	}
    	public void setAge(int value) { 
    		this.age = value;
    	}
    
    	public String toString() { 
    		return "[Person: " +
    				"firstName=" + firstName + " " +
    				"lastName=" + lastName + " " +
    				"age=" + age + "]";
    	}
    
    }

main类

package com.zz.bridge.impl;
    
    
    import java.util.ArrayList;
    import java.util.Arrays;  
    import java.util.Collections;
    import java.util.List;  
    
    import com.zz.bridge.Person;
      
    
    public class BridgeTest
    {
    public static void main(String[] args)
    {
        //生成一个对象，这个对象中包含两个子节点
        Person ted = new Person("Ted", "Neward", 39,
            new Person("Michael", "Neward", 16),
            new Person("Matthew", "Neward", 10));
    
        System.out.println(ted);
        //遍历孩子节点
        for (Person kid : ted)
        {
            System.out.println(kid.getFirstName()+kid.toString());
        }
    }
    }

[Link 1]: http://blog.csdn.net/maoyeqiu/article/details/46449403