java - Align Strings in columns in JTextArea

Question

I want to print Strings in JTextArea and align them properly. Its hard to explain so I will upload the screen shot of what I am trying to achieve.

So Strings printed in each line are printed from Paper object which has parameters (id, title, author, date, rank). The data is read from a text file and is stored in a LinkedList using loadPaper() function.

Then displayPapers() function is used to display content of the Paper object to the JTextArea. displayPapers() is listed below:

/** Print all Paper object present in the LinkedList paperList to textArea */
public void displayPapers(){
    // clear textArea before displaying new content
    displayTxtArea.setText("");

    Paper currentPaper;
    ListIterator<Paper> iter = paperList.listIterator();

    while(iter.hasNext()){
        currentPaper = iter.next();
        String line = currentPaper.toString();

        if("".equals(line)){
            continue;
        } // end if

        String[] words = line.split(",");
        displayTxtArea.append   ("  " 
                                + padString(words[0],30) 
                                + padString(words[1],30) 
                                + "    " 
                                + padString(words[2],30) 
                                + "  " 
                                + padString(words[3],30)  
                                + padString(words[4],30) 
                                + "
");

        System.out.println(words);
        //displayTxtArea.append(currentPaper.toString());
    } // end while

    displayTxtArea.append("  Total " + noOfPapers + " entries!");

} // end showAllPaper

The padString() function adds spaces to the String so that all of them have same number of words. PadString() is listed below:

/** Add spaces to Strings so that all of the are of same number of characters
 *  @param str  String to be padded
 *  @param n    total number words String should be padded to
 * @return str  Padded string 
 */
private String padString(String str, int n){
    if(str.length() < n){
        for(int j = str.length(); j < n; j++){
            str += " ";
        } // end for
    } // end if
    return str;
} // end padString

I have worked on this for a while but still cant get the solution. As you can notice the above picture not everything is perfectly aligned as intended.

How do I align them perfectly so that it looks nicer? Thanks.

Answer 1

Output will be aligned "properly" in your JTextArea only if you use a mono-spaced font. "Andale Mono 14" for example would do the trick.

Also, in order to make your life easier and avoid the padding hell, use String.format with it's syntax.

String format = "%1$5s %2$-40s %3$-20s";
String someLine;
while (whatEver...) {
   ... 
   someLine = String.format(format, aNum, aName, aDate);
   jTextArea1.append(someLine + "
");
}