實(shí)例如下：
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package com.huad.luck;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.List;public class Test { public static void main(String[] args) { Person p = new Person(); p.setName("tom"); p.setAge(11); Person p1 = new Person(); p1.setName("lilei"); p1.setAge(19); Person p2 = new Person(); p2.setName("json"); p2.setAge(15); List<Person> list =new ArrayList<Person>(); list.add(p); list.add(p1); list.add(p2); Collections.sort(list,new Comparator<Person>() { //這里可以再Person中實(shí)現(xiàn) Comparator<T>接口，重寫(xiě)compare方法 @Override public int compare(Person o1, Person o2) { //這里按照名字排序 return o1.getName().compareTo(o2.getName()); //這里按照age排序 //return (o1.getAge()+"").compareTo(o2.getAge()+""); //。。。根據(jù)不同屬性值排序 } }); for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i).getName()); } }}//Person類package com.huad.luck;public class Person{ private String name ; private int age; public Person(String name , int age) { this.name = name; this.age = age; } public Person( ) { } 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; }}<p style="padding-top: 0px; padding-bottom: 0px; margin-top: 8px; margin-bottom: 8px; line-height: 22.5px; letter-spacing: 0.5px; font-size: 12.5px; word-wrap: break-word; word-break: break-all; color: rgb(51, 51, 51); font-family: 'Microsoft YaHei', Verdana, sans-serif, 宋體;"><span style="padding: 0px; margin: 0px; letter-spacing: normal; font-stretch: normal; font-size: 14px; line-height: 24px; font-family: Tahoma; color: rgb(0, 0, 0);">用collection.sort（）方法對(duì)list集合排序</span><br style="padding: 0px; margin: 0px;" /></p><p style="padding-top: 0px; padding-bottom: 0px; margin-top: 0px; margin-bottom: 0px; line-height: 24px; font-size: 14px; word-wrap: break-word; word-break: break-all; font-stretch: normal; font-family: Tahoma;"><span style="padding: 0px; margin: 0px; list-style: none outside none; word-wrap: break-word; word-break: normal;"><span style="padding: 0px; margin: 0px; list-style: none outside none; line-height: 21px; word-wrap: break-word; word-break: normal;"></span></span></p><p style="padding-top: 0px; padding-bottom: 0px; margin-top: 1em; margin-bottom: 0.5em; line-height: 24px; font-size: 14px; word-wrap: break-word; word-break: break-all; font-stretch: normal; font-family: Tahoma;">第一種是list中的對(duì)象實(shí)現(xiàn)Comparable接口，如下：<span style="padding: 0px; margin: 0px; list-style: none outside none; word-wrap: break-word; word-break: normal;"> </span></p><pre class="java" style="padding: 5px; margin-top: 0px; margin-bottom: 0px; line-height: 18px; font-size: 9pt; font-family: 'Courier New', Arial; border: 1px solid rgb(221, 221, 221); color: rgb(51, 51, 51); background: rgb(246, 246, 246);">/** * 根據(jù)order對(duì)User排序 */public class User implements Comparable<User>{ private String name; private Integer order; public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getOrder() { return order; } public void setOrder(Integer order) { this.order = order; } public int compareTo(User arg0) { return this.getOrder().compareTo(arg0.getOrder()); } } |
測(cè)試一下：
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public class Test{ public static void main(String[] args) { User user1 = new User(); user1.setName("a"); user1.setOrder(1); User user2 = new User(); user2.setName("b"); user2.setOrder(2); List<User> list = new ArrayList<User>(); //此處add user2再add user1 list.add(user2); list.add(user1); Collections.sort(list); for(User u : list){ System.out.println(u.getName()); } } } |
輸出結(jié)果如下
a
b
第二種方法是根據(jù)Collections.sort重載方法來(lái)實(shí)現(xiàn)，例如：
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/** * 根據(jù)order對(duì)User排序 */public class User { //此處無(wú)需實(shí)現(xiàn)Comparable接口 private String name; private Integer order; public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getOrder() { return order; } public void setOrder(Integer order) { this.order = order; } } |
主類中這樣寫(xiě)即可：
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public class Test{ public static void main(String[] args) { User user1 = new User(); user1.setName("a"); user1.setOrder(1); User user2 = new User(); user2.setName("b"); user2.setOrder(2); List<User> list = new ArrayList<User>(); list.add(user2); list.add(user1); Collections.sort(list,new Comparator<User>(){ public int compare(User arg0, User arg1) { return arg0.getOrder().compareTo(arg1.getOrder()); } }); for(User u : list){ System.out.println(u.getName()); } } } |
輸出結(jié)果如下
a
b
前者代碼結(jié)構(gòu)簡(jiǎn)單，但是只能根據(jù)固定的屬性排序，后者靈活，可以臨時(shí)指定排序項(xiàng)，但是代碼不夠簡(jiǎn)潔
多字段的場(chǎng)合：
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Collections.sort(list,new Comparator<User>(){ public int compare(User arg0, User arg1) { // 第一次比較專業(yè) int i = arg0.getOrder().compareTo(arg1.getOrder());// 如果專業(yè)相同則進(jìn)行第二次比較 if(i==0){ // 第二次比較 int j=arg0.getXXX().compareTo(arg1.getXXX()); // 如果學(xué)制相同則返回按年齡排序 if(j==0){ return arg0.getCCC().compareTo(arg1.getCCC()); } return j; } return i; } }); |
以下是另外一個(gè)例子
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package test;import java.util.ArrayList; import java.util.Collections; import java.util.Comparator;public class ArrayListTest { public static void main(String[] args) { ArrayList<Exmployee> arrayList = new ArrayList<Exmployee>() ; arrayList.add(new Exmployee("zengqiang",new Integer(5000))) ; arrayList.add(new Exmployee("zengmin",new Integer(4000))) ; arrayList.add(new Exmployee("liuxiaojuan",new Integer(4200))) ; arrayList.add(new Exmployee("giuming",new Integer(2200))) ; Collections.sort(arrayList, new Comparator<Exmployee>(){ public int compare(Exmployee arg0, Exmployee arg1) { return arg1.getSalary()-arg0.getSalary() ; //按照工資升序 //return arg0.getSalary()-arg1.getSalary() ; 按照工資降序 //return arg0.getName().compareTo(arg1.getName()) ; 按照姓名升序 } }); for(Exmployee e:arrayList) System.out.println(e.getName()+"'s salary is "+e.getSalary()) ; }}class Exmployee { public Exmployee(String name, int salary) { this.name = name ; this.salary = salary ; }private String name;public String getName() { return name; }public void setName(String name) { this.name = name; }public int getSalary() { return salary; }public void setSalary(int salary) { this.salary = salary; }private int salary; } |
以上這篇List集合對(duì)象中按照不同屬性大小排序的實(shí)例就是小編分享給大家的全部?jī)?nèi)容了，希望能給大家一個(gè)參考，也希望大家多多支持服務(wù)器之家。
