list java中List对象通用排序算法详解编程语言

/** 
 * 学生实体类 
 * @author chenchuang 
 * 
 */ 
public class Student { 
    public Student(int id, String name, int age) { 
        super(); 
        this.id = id; 
        this.name = name; 
        this.age = age; 
    } 
 
    private int id; 
    private String name; 
    private int age; 
 
    public int getId() { 
        return id; 
    } 
 
    public void setId(int id) { 
        this.id = id; 
    } 
 
    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; 
    } 
}

                                工具类： 

import java.lang.reflect.InvocationTargetException; 
import java.lang.reflect.Method; 
import java.util.Collections; 
import java.util.Comparator; 
import java.util.List; 
 
/** 
 * List对象排序的通用方法 
 *  
 * @author chenchuang 
 *  
 * @param <E> 
 */ 
public class ListSort<E> { 
    /** 
     *  
     * @param list 要排序的集合 
     * @param method 要排序的实体的属性所对应的get方法 
     * @param sort desc 为正序   
     */ 
    public void Sort(List<E> list, final String method, final String sort) { 
        // 用内部类实现排序 
        Collections.sort(list, new Comparator<E>() { 
 
            public int compare(E a, E b) { 
                int ret = 0; 
                try { 
                    // 获取m1的方法名 
                    Method m1 = a.getClass().getMethod(method, null); 
                    // 获取m2的方法名 
                    Method m2 = b.getClass().getMethod(method, null); 
 
                    if (sort != null && "desc".equals(sort)) { 
 
                        ret = m2.invoke(((E)b), null).toString().compareTo(m1.invoke(((E)a),null).toString()); 
 
                    } else { 
                        // 正序排序 
                        ret = m1.invoke(((E)a), null).toString().compareTo(m2.invoke(((E)b), null).toString()); 
                    } 
                } catch (NoSuchMethodException ne) { 
                    System.out.println(ne); 
                } catch (IllegalArgumentException e) { 
                    // TODO Auto-generated catch block 
                    e.printStackTrace(); 
                } catch (IllegalAccessException e) { 
                    // TODO Auto-generated catch block 
                    e.printStackTrace(); 
                } catch (InvocationTargetException e) { 
                    // TODO Auto-generated catch block 
                    e.printStackTrace(); 
                } 
                return ret; 
            } 
        }); 
    } 
}

                                测试类： 

import java.util.ArrayList; 
 
public class ListTest { 
 
    /** 
     * @param args 
     */ 
    public static void main(String[] args) { 
        ArrayList<Student> list= new ArrayList<Student>(); 
        list.add(new Student(1,"张三",5)); 
        list.add(new Student(2,"李四",4)); 
        list.add(new Student(3,"王五",3)); 
        list.add(new Student(4,"小明",2)); 
        list.add(new Student(5,"小黑",1)); 
        ListSort<Student> listSort= new ListSort<Student>(); 
        listSort.Sort(list, "getAge", "desc"); 
        for(Student s:list){ 
            System.out.println(s.getId()+s.getName()+s.getAge()); 
        } 
 
    } 
 
}

                                测试结果 

1张三5 
2李四4 
3王五3 
4小明2 
5小黑1