List对象排序的通用方法

Posted 2020-07-03 MarcoReus

转自 @author chenchuang

 

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 = Double.valueOf(m2.invoke(((E) b), null).toString()).compareTo(Double.valueOf((m1.invoke(((E) a), null).toString())));
                    } else {
                        // 正序排序  
                        ret = Double.valueOf(m1.invoke(((E) a), null).toString()).compareTo(Double.valueOf((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;
            }
        });
    }
}