List的遍历

1.List>的遍历：

Map map =  new  HashMap();

    map.put( "1" ,  "fds" );
    map.put( "2" ,  "valu" );
    List> list =  new  ArrayList>();
    list.add(map);
    for  (Map m : list){
      for  (String k : m.keySet()){
        System.out.println(k +  " : "  + m.get(k));
      }

    }

　2.两个List>相互比较，有相同数据时某些字段相加减

 inOrderList与outOrderList放自己的所比较的数据,name,number,id为map的key值

for  ( int  i =  0 ; i < inOrderList.size(); i++) { //循环获取入库数据
        String number1 = String.valueOf(inOrderList.get(i).get( "number" ));
            String depotName1 = inOrderList.get(i).get( "name" );
            String proId1 = inOrderList.get(i).get( "id" );
            for  ( int  j =  0 ; j < outOrderList.size(); j++) { //循环获取出库数据
                 String number2 = String.valueOf(outOrderList.get(j).get( "number" ));
                 String depotName2 = outOrderList.get(j).get( "name" );
                 String proId2 = outOrderList.get(j).get( "id" );
                if  (depotName1.equals(depotName2) && proId1.equals(proId2)) {
                    Integer sum =Integer.parseInt(number1) - Integer.parseInt(number2); //判断是否为同一条数据，同条数据数量相减
                    inOrderList.get(i).put( "number" , sum +  "" );
                }
            }
        }