JAVA 对象数组按照多个属性进行排序

Love The Way You Lie 2021-06-24 14:00 572阅读 0赞

**下文可以直接拿来运行使用，也可以直接下载附件包，编译直接运行就可以看到效果。**

**//ObjectSort**

package sort;

import java.util.ArrayList;  
import java.util.Collections;  
import java.util.List;

public class ObjectSort \{  
    /\*\*  
     \* @param args  
     \*/  
    public static void main(String\[\] args) \{  
        /\*\*  
         \*

\* purpose： 根据对象的某个或者某些属性排序  
         \* Java里面包含8个基本数据类型，分别是：boolean、byte、char、short、int、float、douboe、long  
         \* 只比较非boolean和byte类型的属性，和大多数运用环境适应，如果有特殊要求，请自己修改。  
         \* 使用时只要将对象属性列表和需要排序的List传入即可  
         \* \*\*/  
        List arrayDemo = new ArrayList();  
         
        Person p1 = new Person();  
        p1.setName("zhang san");  
        p1.setAge(22);  
        p1.setSalary(160);  
         
        Person p2 = new Person();  
        p2.setName("zhang san");  
        p2.setAge(22);  
        p2.setSalary(150);  
         
        Person p3 = new Person();  
        p3.setName("zhang san");  
        p3.setAge(25);  
        p3.setSalary(1900);  
         
        Person p4 = new Person();  
        p4.setName("zhao liu");  
        p4.setAge(25);  
        p4.setSalary(3000);  
         
        Person p5 = new Person();  
        p5.setName("liu qi");  
        p5.setAge(30);  
        p5.setSalary(2000);  
         
        arrayDemo.add(p1);  
        arrayDemo.add(p2);  
        arrayDemo.add(p3);  
        arrayDemo.add(p4);  
        arrayDemo.add(p5);  
         
        //\*\*\*\*\*\*\*\*\*开始比较\*\*\*\*\*\*\*\*//  
        CommonComparator comparator = new CommonComparator();  
        System.out.println("1.sort by name, age and salary");  
        comparator.setFields\_user(new String\[\]\{"name","age","salary"\});  
        Collections.sort(arrayDemo, comparator);  
        for(int i=0;i<arrayDemo.size();i++)  
        \{  
            Person person = (Person)arrayDemo.get(i);  
            System.out.println("name:"+person.getName()+" age:"+person.getAge()+" salary:"+person.getSalary());  
        \}  
          
        System.out.println("1.sort by name, age");  
        comparator.setFields\_user(new String\[\]\{"name","age"\});  
        Collections.sort(arrayDemo, comparator);  
        for(int i=0;i<arrayDemo.size();i++)  
        \{  
            Person person = (Person)arrayDemo.get(i);  
            System.out.println("name:"+person.getName()+" age:"+person.getAge()+" salary:"+person.getSalary());  
        \}  
    \}

**//CommonComparator**

package sort;

import java.lang.reflect.Method;  
import java.math.BigDecimal;  
import java.text.CollationKey;  
import java.text.Collator;  
import java.util.Comparator;

public class CommonComparator implements Comparator \{

/\*\*\*  
     \* @param  
     \* 比较对象的属性用String\[\]的形式传过来  
     \* 比较的对象一定要符合javaBean，即要有Set,Get方法  
     \* \*/  
    String\[\] fields\_user = null;  
     
     
    public String\[\] getFields\_user() \{  
        return fields\_user;  
    \}  
    public void setFields\_user(String\[\] fields\_user) \{  
        this.fields\_user = fields\_user;  
    \}  
    /\*\*  
     \* 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,类是sql order by  
     \* 即只要比较出同位置的属性就停止  
     \* \*/  
    public int compare(Object obj1, Object obj2)  
    \{  
        //没有属性，则不排序  
        if(fields\_user == null || fields\_user.length<=0)  
        \{  
            return 2;//不比较  
        \}  
        for(int i=0;i<fields\_user.length;i++)  
        \{  
            //return compareField(obj1,obj2,fields\_user\[i\]);  
            if(compareField(obj1,obj2,fields\_user\[i\])>0)  
            \{//如果obj1的属性值大于obj2的属性值，则返回正数  
                return 1;  
             \}else if(compareField(obj1,obj2,fields\_user\[i\])<0)\{  
                 return -1;  
             \}  
        \}  
        return 0;  
    \}  
    /\*\*  
     \* @param fieldName  
     \* 根据属性名排序  
     \* \*/  
    private static int compareField(Object o1,Object o2,String fieldName)  
    \{  
            try  
            \{  
                Object value1 = getFieldValueByName(fieldName,o1);  
                Object value2 = getFieldValueByName(fieldName,o2);  
                
                //--字符串比较  
                if(value1 instanceof String)  
                \{  
                  String v1 = getFieldValueByName(fieldName,o1).toString();  
                  String v2 = getFieldValueByName(fieldName,o2).toString();  
                    Collator myCollator = Collator.getInstance();  
                    CollationKey\[\] keys = new CollationKey\[5\];  
                    keys\[0\] = myCollator.getCollationKey(v1);  
                    keys\[1\] = myCollator.getCollationKey(v2);  
                    return (keys\[0\].compareTo(keys\[1\]));  
                \}  
                //--非比较属性不比较  
                else if("java.lang.Boolean".equals(value1.getClass().getName()) || "java.lang.Byte".equals(value1.getClass().getName()))  
                \{  
                    return 0;  
                \}else  
                \{  
                    BigDecimal b1 = new BigDecimal(value1.toString());  
                    BigDecimal b2 = new BigDecimal(value2.toString());  
                    return b1.compareTo(b2);  
                \}

\} catch (Exception e)  
            \{  
                System.out.println("-----------------------------------------------------------------------------");  
                System.out.println("---------对象的该属性不存在或者不允许在此安全级别上反射该属性，详情请查阅JAVA DOC--------");  
                System.out.println("-----------------------------------------------------------------------------");  
                e.printStackTrace();  
            \}  
            //小于  
            return -1;  
    \}  
    /\*\*  
     \* @param  
     \* fieldName 属性名  
     \* obj 对象  
     \* 反射获得该属性的值  
     \* \*/  
    private static Object getFieldValueByName(String fieldName,Object obj)  
    \{  
        try  
        \{  
            String Letter = fieldName.substring(0,1).toUpperCase();  
            String methodStr = "get"+Letter+fieldName.substring(1);  
            Method method = obj.getClass().getMethod(methodStr, new Class\[\]\{\});  
     
            Object value = method.invoke(obj, new Object\[\]\{\});  
              
            return value;  
        \}catch(Exception e)  
        \{  
            System.out.println("------------------------------------------------------");  
            System.out.println("---------该"+fieldName+"属性不存在----------------------");  
            System.out.println("------------------------------------------------------");  
            return null;  
        \}  
    \}

**//Person**

package sort;

public class Person \{  
    public Person()\{\}  
      
    private String name;  
    private int age;  
    private long salary;  
     
    public long getSalary() \{  
        return salary;  
    \}  
    public void setSalary(long salary) \{  
        this.salary = salary;  
    \}  
    public int getAge() \{  
        return age;  
    \}  
    public void setAge(int age) \{  
        this.age = age;  
    \}  
    public String getName() \{  
        return name;  
    \}  
    public void setName(String name) \{  
        this.name = name;  
    \}