java對象屬性排序，支持中英文字符串和數字

廢話不多說，該類主要實現按對象屬性將對象排序，排序可以按任意多屬性進行排序，類似sql的order by，還可以設置排序是升序還是降序。

 

 import java.lang.reflect.Method; import java.text.Collator; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; /** * @author 鄔小洪 QQ:16044171 * @version 1.0,2010-7-24 */ public class MyComparator implements Comparator { private Comparator cmp = Collator.getInstance(java.util.Locale.CHINA); private String[] sortBy; private int order; private MyComparator(String[] sortBy, int order) { this.sortBy = sortBy; this.order = order; } /* * 定義排序規則 如果按照不止一個屬性進行排序 這按照屬性的順序進行排序,類似sql order by 即只要比較出同位置的屬性就停止 */ public int compare(Object o1, Object o2) { for (int i = 0; i < sortBy.length; i++) { Object value1 = getFieldValueByName(sortBy[i], o1); Object value2 = getFieldValueByName(sortBy[i], o2); if (value1 instanceof Integer && value2 instanceof Integer) { int v1 = Integer.parseInt(value1.toString()); int v2 = Integer.parseInt(value2.toString()); if (v1 > v2) { return 1 * this.order; } else if (v1 < v2) { return -1 * this.order; } } else { int result = cmp.compare(value1, value2); if (result != 0) { return result * this.order; } } } return -1 * this.order; } /** * * 通過反射，獲取屬性值 * * @param fieldName * @param o * @return */ private Object getFieldValueByName(String fieldName, Object o) { try { String firstLetter = fieldName.substring(0, 1).toUpperCase(); String getter = "get" + firstLetter + fieldName.substring(1); Method method = o.getClass().getMethod(getter, new Class[] {}); Object value = method.invoke(o, new Object[] {}); return value; } catch (Exception e) { System.out.println("屬性不存在"); return null; } } /** * * 待排序對象 * * @author 鄔小洪 QQ:16044171 * @version 1.0,2010-7-24 */ private static class Bean { private String name = null; private String post = null; private Integer age = null; public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getPost() { return post; } public void setPost(String post) { this.post = post; } public String getName() { return name; } public void setName(String name) { this.name = name; } } public static void main(String[] args) { Bean b1 = new Bean(); b1.setName("鄔小洪"); b1.setPost("研發工程師"); b1.setAge(26); Bean b2 = new Bean(); b2.setName("小洪"); b2.setPost("部署工程師"); b2.setAge(27); Bean b3 = new Bean(); b3.setName("洪兒"); b3.setPost("部署工程師"); b3.setAge(28); Bean b4 = new Bean(); b4.setName("鄔小洪"); b4.setPost("架構工程師"); b4.setAge(27); List<Bean> list = new ArrayList<Bean>(); list.add(b1); list.add(b2); list.add(b3); list.add(b4); String[] sortBy = new String[] { "name", "post" }; int orderBy = 1;//1:升序，-1：降序 MyComparator myCmp = new MyComparator(sortBy, orderBy); Collections.sort(list, myCmp); System.out.println("--------------------按名字和職位升序----------------------------"); for (Bean b : list) { System.out.println("name:" + b.getName() + ",post:" + b.getPost() + ",age:" + b.getAge()); } sortBy = new String[] { "post", "age" }; myCmp = new MyComparator(sortBy, orderBy); Collections.sort(list, myCmp); System.out.println("--------------------按職位和年齡升序----------------------------"); for (Bean b : list) { System.out.println("post:" + b.getPost() + ",age:" + b.getAge() + ",name:" + b.getName()); } sortBy = new String[] { "age", "name" }; myCmp = new MyComparator(sortBy, orderBy); Collections.sort(list, myCmp); System.out.println("--------------------按年齡和名字升序----------------------------"); for (Bean b : list) { System.out.println("age:" + b.getAge() + ",name:" + b.getName() + ",post:" + b.getPost()); } } }

 

運行結果：

--------------------按名字和職位升序----------------------------
name:洪兒,post:部署工程師,age:28
name:小洪,post:部署工程師,age:27
name:鄔小洪,post:研發工程師,age:26
name:鄔小洪,post:架構工程師,age:27
--------------------按職位和年齡升序----------------------------
post:部署工程師,age:27,name:小洪
post:部署工程師,age:28,name:洪兒
post:架構工程師,age:27,name:鄔小洪
post:研發工程師,age:26,name:鄔小洪
--------------------按年齡和名字升序----------------------------
age:26,name:鄔小洪,post:研發工程師
age:27,name:小洪,post:部署工程師
age:27,name:鄔小洪,post:架構工程師
age:28,name:洪兒,post:部署工程師