java比較子Comparator 使用

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PresonDemo

package cn.stat.p5.person.demo;public class PresonDemo implements Comparable  {    private String name;    private int age;        /**     * @param args     */    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public void outPrint()    {                System.out.println(this.age+".."+this.name);    }    public PresonDemo(String name, int age) {            this.name = name;        this.age = age;    }    //TreeSet();為空白時，實列類內部比較子    @Override    public int compareTo(Object o) {        // TODO Auto-generated method stub        PresonDemo p=(PresonDemo)o;        if(p.age<this.age)            return 1;        if(p.age>this.age)            return-1;        return 0;    }}

 

比較子CompartorbyName

/** * 根據名子比較返回順序 */package cn.stat.p6.arraylist.demo;import java.util.Comparator;import cn.stat.p5.person.demo.PresonDemo;/** * @author Administrator * */public class CompartorbyName implements Comparator {    /* (non-Javadoc)     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)     */    @Override    public int compare(Object o1, Object o2) {        // TODO Auto-generated method stub        PresonDemo p1=(PresonDemo)o1;        PresonDemo p2=(PresonDemo)o2;        int temp=p1.getName().compareTo(p2.getName());        return temp==0?p1.getAge()-p2.getAge():temp;    }}

TreeSetDemo

package cn.stat.p6.arraylist.demo;import cn.stat.p5.person.demo.PresonDemo;import java.util.Iterator;import java.util.TreeSet;import java.util.ArrayList;public class TreeSetDemo {     public static void main(String[] args) {        TreeSet ts=new TreeSet(new CompartorbyName()); //比較子                   ts.add(new PresonDemo("list1",2));            ts.add(new PresonDemo("list9",2));            ts.add(new PresonDemo("list7",2));            ts.add(new PresonDemo("list4",2));            ts.add(new PresonDemo("list5",2));            Iterator<PresonDemo> it=ts.iterator();        while(it.hasNext())        {            PresonDemo p=(PresonDemo)it.next();            System.out.println(p.getName()+"  "+p.getAge());                    }    }}

 

java比較子Comparator 使用