按字母顺序排列arraylist（不区分大小写）

I have a string arraylist names which contains names of people. I want to sort the arraylist in alphabetical order.

我有一个字符串arraylist名称，其中包含人的名字。我想按字母顺序对arraylist进行排序。

ArrayList<String> names = new ArrayList<String>();
names.add("seetha");
names.add("sudhin");
names.add("Swetha");
names.add("Neethu");
names.add("ananya");
names.add("Athira");
names.add("bala");
names.add("Tony");
names.add("Karthika");
names.add("Nithin");
names.add("Vinod");
names.add("jeena");
Collections.sort(names);
for(int i=0; i<names.size(); i++)
    System.out.println(names.get(i));

I tried to sort the list in above way. But it is displaying the sorted array as:

我试图以上述方式对列表进行排序。但是它将排序的数组显示为：

Athira
Karthika
..
..
ananya
bala
...

but I don't want to make it case sensitive. I want the result as:

但我不想让它区分大小写。我希望结果如下：

ananya
Athira
bala

6 个解决方案

#1

281

Custom Comparator should help

自定义比较器应该有所帮助

Collections.sort(list, new Comparator<String>() {
    @Override
    public int compare(String s1, String s2) {
        return s1.compareToIgnoreCase(s2);
    }
});

Or if you are using Java 8:

或者如果您使用的是Java 8：

list.sort(String::compareToIgnoreCase);

#2

174

The simplest thing to do is:

最简单的事情是：

Collections.sort(list, String.CASE_INSENSITIVE_ORDER);

#3

try this code

试试这段代码

Collections.sort(yourarraylist, new SortBasedOnName());



import java.util.Comparator;
import com.RealHelp.objects.FBFriends_Obj;
import com.RealHelp.ui.importFBContacts;

public class SortBasedOnName implements Comparator
{
public int compare(Object o1, Object o2) 
{

    FBFriends_Obj dd1 = (FBFriends_Obj)o1;// where FBFriends_Obj is your object class
    FBFriends_Obj dd2 = (FBFriends_Obj)o2;
    return dd1.uname.compareToIgnoreCase(dd2.uname);//where uname is field name
}

}

#4

Based on the above mentioned answers, I managed to compare my custom Class Objects like this:

根据上面提到的答案，我设法比较我的自定义类对象，如下所示：

ArrayList<Item> itemList = new ArrayList<>();
...
Collections.sort(itemList, new Comparator<Item>() {
            @Override
            public int compare(Item item, Item t1) {
                String s1 = item.getTitle();
                String s2 = t1.getTitle();
                return s1.compareToIgnoreCase(s2);
            }

        });

#5

You need to use custom comparator which will use compareToIgnoreCase, not compareTo.

您需要使用自定义比较器，它将使用compareToIgnoreCase，而不是compareTo。

#6

Starting from Java 8 you can use Stream:

从Java 8开始，您可以使用Stream：

List<String> sorted = Arrays.asList(
                          names.stream().sorted(
                              (s1, s2) -> s1.compareToIgnoreCase(s2)
                          ).toArray(String[]::new)
                      );

It gets a stream from that ArrayList, then it sorts it (ignoring the case). After that, the stream is converted to an array which is converted to an ArrayList.

它从ArrayList获取一个流，然后对其进行排序（忽略大小写）。之后，流被转换为一个转换为ArrayList的数组。

If you print the result using:

如果使用以下方法打印结果：

System.out.println(sorted);

you get the following output:

你得到以下输出：

[ananya, Athira, bala, jeena, Karthika, Neethu, Nithin, seetha, sudhin, Swetha, Tony, Vinod]

#1

281