java对象属性排序，支持中英文字符串和数字

jp乞巧楼 2015-07-30

展开全文

废话不多说，该类主要实现按对象属性将对象排序，排序可以按任意多属性进行排序，类似sql的order by，还可以设置排序是升序还是降序。

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 邬小洪 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;
}
/*
* 定义排序规则如果按照不止一个属性进行排序这按照属性的顺序进行排序,类似sql order by 即只要比较出同位置的属性就停止
*/
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;
}
/**
*
* 通过反射，获取属性值
*
* @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("属性不存在");
return null;
}
}
/**
*
* 待排序对象
*
* @author 邬小洪 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("邬小洪");
b1.setPost("研发工程师");
b1.setAge(26);
Bean b2 = new Bean();
b2.setName("小洪");
b2.setPost("部署工程师");
b2.setAge(27);
Bean b3 = new Bean();
b3.setName("洪儿");
b3.setPost("部署工程师");
b3.setAge(28);
Bean b4 = new Bean();
b4.setName("邬小洪");
b4.setPost("架构工程师");
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("--------------------按名字和职位升序----------------------------");
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("--------------------按职位和年龄升序----------------------------");
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("--------------------按年龄和名字升序----------------------------");
for (Bean b : list) {
System.out.println("age:" + b.getAge() + ",name:" + b.getName()
+ ",post:" + b.getPost());
}
}
}

运行结果：

--------------------按名字和职位升序----------------------------
name:洪儿,post:部署工程师,age:28
name:小洪,post:部署工程师,age:27
name:邬小洪,post:研发工程师,age:26
name:邬小洪,post:架构工程师,age:27
--------------------按职位和年龄升序----------------------------
post:部署工程师,age:27,name:小洪
post:部署工程师,age:28,name:洪儿
post:架构工程师,age:27,name:邬小洪
post:研发工程师,age:26,name:邬小洪
--------------------按年龄和名字升序----------------------------
age:26,name:邬小洪,post:研发工程师
age:27,name:小洪,post:部署工程师
age:27,name:邬小洪,post:架构工程师
age:28,name:洪儿,post:部署工程师