java&android 中list集合排序工具类

user实体

public class User {
	private int id;
	private String name;
	private String age;
	
	public User(int id, String name, String age) {
		this.id = id;
		this.name = name;
		this.age = 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 String getAge() {
		return age;
	}
	public void setAge(String age) {
		this.age = age;
	}
	
	

}

工具类编写

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

class Util<T> {
    //数组排序的方法
    //传入list  传入排序字段 传入是否升序
    public List<T> sort(List<T> list, final String  sortField, final Boolean Ascending){

        Collections.sort(list, new Comparator<T>() {//排序
            @Override
            public int compare(T o1, T o2) {
                int retVal=0;
                //首字母转大写
                String newStr=sortField.substring(0, 1).toUpperCase()+sortField.replaceFirst("\\w","");
                String methodStr="get"+newStr;
                try {
                    Method method1 = ((T) o1).getClass().getMethod(methodStr, null);
                    Method method2 = ((T) o2).getClass().getMethod(methodStr, null);
                    retVal = method2.invoke(((T) o2), null).toString().compareTo(method1.invoke(((T) o1), null).toString()); // 倒序
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                } catch (NoSuchMethodException e) {
                    e.printStackTrace();
                }
                if (Ascending) {
                    return 0-retVal;
                } else {
                    return retVal;
                }
            }
        });
        return list;
    }

}

测试类

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

public class bb {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//System.out.print("123");
		
		List<User> userlist=new ArrayList<>();
		User user=new User(1, "张1", "15");
		userlist.add(user);
		 user=new User(5, "张5", "15");
		 userlist.add(user);
		 user=new User(2, "张2", "15");
		 userlist.add(user);
		 user=new User(4, "张4", "15");
		 userlist.add(user);
		 System.out.println("排序前");
		 for(int i=0;i<userlist.size();i++) {
			 System.out.println(userlist.get(i).getName());
		 }
		 System.out.println("升序排序");
		 Util util=new Util<User>();
		 util.sort(userlist, "id", true);
		 
		 for(int i=0;i<userlist.size();i++) {
			 System.out.println(userlist.get(i).getName());
		 }
		 System.out.println("倒序排序");
		 util.sort(userlist, "id", false);
		 
		 for(int i=0;i<userlist.size();i++) {
			 System.out.println(userlist.get(i).getName());
		 }
		
	}

}