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UTF-8 and JTextArea

I have 2 JTextArea, one of them contains unicode like this \ u0645. I want a different JTextArea

show the Unicode symbolic representation of this code. If you pass this code point to the JTextArea it will show

code point not Character, but if I find code in the setText method of JTextArea it works correctly!

why? and can I pass String of Codepoint from one JTextArea to another?

thanks

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3 answers


This code displays a character, and the corresponding "unicode string" matches in another text area:

import java.awt.*;

import javax.swing.*;
public class FrameTest {
    public static void main(String[] args) {
        JFrame jf = new JFrame("Demo");
        Container cp = jf.getContentPane();
        cp.setLayout(new BorderLayout());
        JTextArea ta1 = new JTextArea(20, 20);
        JTextArea ta2 = new JTextArea(20, 20);
        Character c = '\u0645';
        ta1.setText("" + c);
        String s = String.format("\\%04x", (int) c.charValue());
        ta2.setText(s);
        cp.add(ta1, BorderLayout.WEST);
        cp.add(ta2, BorderLayout.EAST);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setSize(500, 100);
        jf.setVisible(true);
    }
}

enter image description here



So, if you have long text of such characters, you will need to loop through the character of the string by character using getCharAt(int)

or getChars()

) and process each character with String.format("\\%04x", (int) c.charValue());

and add the result to the target string. (Use preferred StringBuffer

.)

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JTextArea text=new JTextArea();

String dir=text.getText();

JTextArea text2=new  JTextArea();

text2.setText(dir);

but it doesn't work, dir contains a line with code points. If I pass the String of the code point directly to



setText ("\ u0645 \ u0645") it works!

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If I set the code pointing to the setText method of the JTextArea it works correctly!

If by that you mean something like myTextArea.setText('\u0645')

, then the problem is pretty clear:

Java compiler interprets unicode escape\u

as start . This means that in Java source code, all characters are completely equivalent to actually putting the character (Unicode character U + 0645 ARABIC LETTER MEEM ) in the same place.\u0645

م

So the next two lines do the same:

myTextArea.setText('\u0645')
myTextArea.setText('م')

The reason for this is that it is \u0645

converted to the corresponding Unicode character at compile time .

This is a completely different situation if you have a Java string that contains 6 characters \u0645

. This string can be represented as a Java string literal "\\u0645"

(note the double backslash to avoid the compiler interpreting the Unicode escape code).

In this case, you can grab from the third to the last character ( "\\u0645".subString(2)

), parse it as a hexadecimal number (s Integer.parseInt(theString, 16)

), and pipe the result to char

. Then you will get a value char

containing the actual Unicode character.

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