CODEWITHSUNDEEP
javaandroid
amin.mp
amin.mp

Reputation: 61

How can I sort List<Object> by String value (Persian Alphabet)?

I have a List of Student with tow fields (name & number), I want to sort the List by name (Persian name) but When I sort the List with Collections.sort there is problem with some Persian Alphabet like "ک" & "گ" & "ژ" &... The result is: "ی" , "ک" , "م" But it must be: "ی" , "م" , "ک"

Here is my code:

 public class Student {
    private String name;
    private int number;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", number=" + number +
                '}';
    }

}

public class Main {

    public static void main(String[] args) {

            List<Student> studentList = new ArrayList<Student>();

            Student temp1 = new Student();
            temp1.setName("ی");
            temp1.setNumber(5);

            Student temp2 = new Student();
            temp2.setName("م");
            temp2.setNumber(4);

            Student temp3 = new Student();
            temp3.setName("ک");
            temp3.setNumber(3);

            studentList.add(temp1);
            studentList.add(temp2);
            studentList.add(temp3);

            // before sort
            System.out.println("before sort");
            for(Student student : studentList){
                    System.out.println("Student name: " + student.getName());
            }

            Locale locale = new Locale("fa");

            System.out.println("--------------------");
            System.out.println("Language: " + locale.getDisplayLanguage());
            System.out.println("--------------------");

            if (studentList.size() > 0) {
                    Collections.sort(studentList, new Comparator<Student>() {
                            @Override
                            public int compare(final Student object1, final Student object2) {
                                    return Collator.getInstance(locale).compare(object1.getName(), object2.getName());
                            }
                    } );
            }

            // after sort
            System.out.println("after sort");
            for(Student student : studentList){
                    System.out.println("Student name: " + student.getName());
            }

    }

}

Upvotes: 6

Views: 1721

Answers (4)

Reza
Reza

Reputation: 875

With the help of G3ntle_Man answer, if you use Java 8 this can be done using stream() like this

mStringList.stream().sorted(
                        (string1, string2) -> Collator.getInstance(
                                new Locale("fa", "IR"))
                                .compare(string1, string2)).collect(Collectors.toList());

Upvotes: 0

M.mhr
M.mhr

Reputation: 1759

Use Collator with a new locate for "IR" :

Collator.getInstance(new Locale("fa", "IR")).compare ...

Upvotes: 2

aldebaran-ms
aldebaran-ms

Reputation: 666

You can use a collator, take a look at this:

Performing Locale-Independent Comparisons

Sorting arabic words in java

Or create your own Comparator. Here the doc.

Object Ordering

The reason you are getting those strings sorted in that way is that strings are sorted using the UTF-16 char table. So in UTF-16 those characters are:

  • م ARABIC LETTER MEEM (U+0645)
  • ک ARABIC LETTER KEHEH (U+06A9)
  • ی ARABIC LETTER FARSI YEH (U+06CC)

Upvotes: 3

user140547
user140547

Reputation: 8200

If such a Locale is not available in the JDK, most likely someone has already written such a library for Java. I didn't find any libraries, but maybe you can find one when you know the language.

Upvotes: 0

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