如何在Java中将逗号分隔的字符串转换为ArrayList
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/18104278/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to convert a comma separated String to ArrayList in Java
提问by
I have a comma separated String which i need to convert to ArrayList . I tried this way
我有一个逗号分隔的 String ，我需要将其转换为 ArrayList 。我试过这种方式
import java.util.ArrayList;
import java.util.Arrays;
public class Test {
public static void main(String[] args) {
String CommaSeparated = "item1 , item2 , item3";
ArrayList<String> items = (ArrayList)Arrays.asList(CommaSeparated.split("\s*,\s*"));
for(String str : items)
{
System.out.println(str);
}
}
}
Its giving me the Runtime Error as shown
它给了我运行时错误，如图所示
Exception in thread "main" java.lang.ClassCastException: java.util.Arrays$ArrayList cannot be cast to java.util.ArrayList
at com.tradeking.at.process.streamer.Test.main(Test.java:14)
as i was trying to convert an List to arrayList by force .
因为我试图强制将 List 转换为 arrayList 。
采纳答案by Rohit Jain
The ArrayListreturned by Arrays.asListis not java.util.ArrayList. It's java.util.Arrays.ArrayList. So you can't cast it to java.util.ArrayList.
该ArrayList由归国Arrays.asList不是java.util.ArrayList。它是java.util.Arrays.ArrayList。所以你不能把它投射到java.util.ArrayList.
You need to pass the list to the constructor of java.util.ArrayListclass:
您需要将列表传递给java.util.ArrayList类的构造函数：
List<String> items = new ArrayList<String>(Arrays.asList(CommaSeparated.split("\s*,\s*")));
or, you can simply assign the result:
或者，您可以简单地分配结果：
List<String> items = Arrays.asList(CommaSeparated.split("\s*,\s*"));
but mind you, Arrays.asListreturns a fixed size list. You cannot add or remove anything into it. If you want to add or remove something, you should use the 1st version.
但请注意，Arrays.asList返回一个固定大小的列表。您不能在其中添加或删除任何内容。如果要添加或删除某些内容，则应使用第一个版本。
P.S: You should use Listas reference type instead of ArrayList.
PS：您应该使用List作为引用类型而不是ArrayList.
回答by Kayaman
You can't just cast objects around like they're candy. Arrays.asList()doesn't return an ArrayList, so you can't cast it (it returns an unmodifiable List).
你不能像扔糖果一样随意扔东西。Arrays.asList()不返回ArrayList，所以你不能投射它（它返回一个不可修改的列表）。
However you can do new ArrayList(Arrays.asList(...));
但是你可以做 new ArrayList(Arrays.asList(...));
回答by Chris Thompson
Does it absolutely need to be an ArrayList? Typically you want to use the most generic form. If you're ok using a Listjust try:
它绝对需要是一个ArrayList吗？通常，您希望使用最通用的形式。如果您可以使用List，请尝试：
List<String> items = Arrays.asList(...);
You can still iterate over it the same way you currently are.
您仍然可以像当前一样迭代它。
回答by Kwak Young Ho
String CommaSeparated = "item1 , item2 , item3";
ArrayList<String> items = new ArrayList(Arrays.asList(CommaSeparated.split("\s*,\s*")));
for(String str : items)
{
System.out.println(str);
}
回答by nilesh patel
Please try to use bellow code.
请尝试使用以下代码。
String[] temp;
字符串[] 温度；
/* delimiter */
String delimiter = ",";
/*
* given string will be split by the argument delimiter provided.
*/
temp = parameter.split(delimiter);
ArrayList<String> list = new ArrayList<String>();
for (int l = 0; l < temp.length; l++)
{
list.add(temp[l]);
}
