How to set different colors to ArrayList content in Java

Question

I am scanning the files with different extension and putting them in String ArrayList in Java(the names with extension). I want to print with different colors into JTextArea by looking the extesions for example .xls extension as green color , .txt extension as blue color. Here is my code below ;

public void setScanResult(ArrayList<String> x)
{
    textArea.append("|");

    for (int i = 0; i < x.size(); i++) {                
        textArea.append("\n");
        textArea.append((String) x.get(i));                
    }    
    x.clear();
}

Answer 1

For coloring text use JTextPane instead of JTextArea, here is simple example:

import java.awt.Color;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.text.AttributeSet;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyleContext;

public class Example extends JFrame{

    private JTextPane pane;
    public Example(){
        init();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    private void init() {
        JScrollPane p = new  JScrollPane(pane = new JTextPane());
        add(p);
        List<String> files = new ArrayList<>();
        files.add("1.txt");
        files.add("2.txt");
        files.add("3.doc");
        files.add("4.xls");
        for(String s : files){
            addText(s);
        }
    }

    private void addText(String s) {
        Color color = getColor(s);
        StyleContext style = StyleContext.getDefaultStyleContext();
        AttributeSet attrs = style.addAttribute(SimpleAttributeSet.EMPTY,StyleConstants.Foreground, color);
        pane.setCaretPosition(pane.getDocument().getLength());
        pane.setCharacterAttributes(attrs , false);
        pane.replaceSelection(s+"\n");
    }

    private Color getColor(String s) {
        return  s.endsWith(".txt") ? Color.RED : (s.endsWith(".doc") ? Color.GREEN : Color.CYAN );
    }

    public static void main(String... s){
        new Example();
    }
}