将重复的数据合并成一行-反射

将重复的数据合并成一行，希望能做个参考

package com.jy.common;

import com.jy.model.OrderHandling;

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;

public class DistinctUtils {
    //传入一个集合，将里面的数据根据某个字段判断重复，将一个或者多个值合并

    /**
     *
     * @param objLIst 传入一个集合,只对对象有效
     * @param selectNumber 去重字段
     * @param merge     将参数合并
     * @return 过滤后的集合
     */
    public static List<?> DistinctUtils(List<?> objLIst,String selectNumber,String merge ) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InstantiationException, InvocationTargetException, IntrospectionException {
        WeakHashMap  map=new WeakHashMap();
        ArrayList list = new ArrayList();
        selectNumber="get"+selectNumber;
    String    changeMerge="get"+merge;
for(int i=0;i<objLIst.size();i++){
  Object newClass=  objLIst.get(i);//获取class
    Method method = newClass.getClass().getMethod(selectNumber);//获取名称OrderNumber
    String OrderNumber =(String)method.invoke(newClass);//执行方法
    Method mergemethod = newClass.getClass().getMethod(changeMerge);//获取名称CargoName
    String CargoName = (String)mergemethod.invoke(newClass);//执行方法
if(map.containsKey(OrderNumber)){//有了
     //CargoName
        StringBuffer sb=new StringBuffer();
        //获取的是上一个对象，所以还是要创建
        Object keynewClass = map.get(OrderNumber);
        //获取名称OrderNumber
        Method keymergemethod = keynewClass.getClass().getMethod(changeMerge);
        //执行方法
        String keyCargoName =(String)keymergemethod.invoke(keynewClass);
        //上一个值，或者初始值
        sb.append(keyCargoName);
        //当前值
        sb.append(","+CargoName);
        //拼装好的数据
        String value = sb.toString();
        //调用set方法 名称，对象class，修改后
        PropertyDescriptor pd = new PropertyDescriptor(merge,newClass.getClass());
        Method setMethod = pd.getWriteMethod();
        //拿到当前循环对象。修改set merge方法
        setMethod.invoke(newClass, value);
        //map返回
        map.put(OrderNumber,newClass);
    }else{  //没有
        map.put(OrderNumber,newClass);
    }
}
        //循环对象map
        for (Object v : map.values()) {
            list.add(v);
        }
        map=null;

        return  list;
    }



    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException, IntrospectionException {
        List<OrderHandling> orderHandlingss =new ArrayList<OrderHandling>();
        int size = orderHandlingss.size();
        OrderHandling or=new OrderHandling();
        or.setOrd_number("001");
        or.setCargoName("测试001");
        orderHandlingss.add(or);
        OrderHandling or2=new OrderHandling();
        or2.setOrd_number("001");
        or2.setCargoName("测试002");
        orderHandlingss.add(or2);
        OrderHandling or3=new OrderHandling();
        or3.setOrd_number("001");
        or3.setCargoName("测试003");
        orderHandlingss.add(or3);
        OrderHandling or33=new OrderHandling();
        or33.setOrd_number("002");
        or33.setCargoName("yang");
        orderHandlingss.add(or33);
        OrderHandling or23=new OrderHandling();
        or23.setOrd_number("001");
        or23.setCargoName("测试0023");
        orderHandlingss.add(or23);
        List<OrderHandling> objects = (List<OrderHandling>) DistinctUtils.DistinctUtils(orderHandlingss, "Ord_number", "CargoName");
        System.out.println(objects.toString());
    }
}