Question

嗨我有两个对象的ArrayList，我需要将它合并为一个列表。这是我的要求

我的第一个列表

利斯塔

{StaffFirstName=f2, resourceId=2, totalcost=18055.0, totalPercentageInvolvment=550, ResourceCost=2300, staffRole=tl}

和listB

{sixthmonth=60, fourthmonth=40, firstmonth=10, fifthmonth=50, secondmonth=20, `thirdmonth=30}`

我需要结果

结果

{StaffFirstName=f2, resourceId=2, totalcost=18055.0, totalPercentageInvolvment=550, ResourceCost=2300, staffRole=tl, sixthmonth=60, fourthmonth=40, firstmonth=10, fifthmonth=50, secondmonth=20, thirdmonth=30}

修改<！/强>

实际上我的两个列表都是arrayList所以我的listA将是

{StaffFirstName=f2, resourceId=2, totalcost=18055.0, totalPercentageInvolvment=550, ResourceCost=2300, staffRole=tl} {StaffFirstName=demo35, resourceId=3, totalcost=19625.0, totalPercentageInvolvment=785, ResourceCost=2500, staffRole=sweeper}

和列表B将是

{sixthmonth=100, fourthmonth=30, firstmonth=40, fifthmonth=25, secondmonth=100, thirdmonth=90} {sixthmonth=100, fourthmonth=30, firstmonth=40, fifthmonth=25, secondmonth=100, thirdmonth=90}

，结果应为

{StaffFirstName=f2, resourceId=2, totalcost=18055.0, totalPercentageInvolvment=550, ResourceCost=2300, staffRole=tl, sixthmonth=60, fourthmonth=40, firstmonth=10, fifthmonth=50, secondmonth=20, thirdmonth=30} {StaffFirstName=demo35, resourceId=3, totalcost=19625.0, totalPercentageInvolvment=785, ResourceCost=2500, staffRole=sweeper, sixthmonth=100, fourthmonth=30, firstmonth=40, fifthmonth=25, secondmonth=100, thirdmonth=90}

这意味着我的两个列表中的每一行都必须附加我的行。如果我使用addAll函数，则两个列表就像这样添加

{StaffFirstName=f2, resourceId=2, totalcost=18055.0, totalPercentageInvolvment=550, ResourceCost=2300, staffRole=tl} {StaffFirstName=demo35, resourceId=3, totalcost=19625.0, totalPercentageInvolvment=785, ResourceCost=2500, staffRole=sweeper} {sixthmonth=60, fourthmonth=40, firstmonth=10, fifthmonth=50, secondmonth=20, thirdmonth=30} {sixthmonth=100, fourthmonth=30, firstmonth=40, fifthmonth=25, secondmonth=100, thirdmonth=90}. But i need to append the two list row wise. Is it possible?

Answer 1

鉴于：

   List<MyClass> listA, listB;

试试这个：

   List<MyClass> union = new ArrayList<MyClass>();
   union.addAll( listA );
   union.addAll( listB );

Answer 2

我不太确定你拥有的是ArrayList（来自输出），但即便如此，如果它是一个实现Collection接口的类，你可以使用{{ 1}}方法，独立于确切的类（只要对象属于同一类型）。

http://docs.oracle.com/javase/6/docs/api/java/util/Collections.html#addAll(java.util.Collection，T ...）

Answer 3

如果这些是ArrayList＆lt;＆gt;包含相同类型的对象，您可以使用：

list1.addAll(list2);

它应该可以正常工作。

Answer 4

Type是数组的类型....

 Type[] concat(Type[] listA, Type[] listB) 
     {
       Type[] list= new Type[listA.length+listB.length];
       System.arraycopy(listA, 0, list, 0, listA.length);
       System.arraycopy(listB, 0, list, listA.length, listB.length);

       return list;
     }

如何在java中将两个对象列表连接成一个

4 个答案: