Limiting Fields Characters

// LimitDocument.java

package edu.tup.prepaid_canteen.actions;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;

/**
 * Limit the document's number of input characters.
 * @author Liezl Alfaro & Erieze Lagera
 */
public class LimitDocument extends PlainDocument {

    private int limit;

    /**
     * Setup the parameter for number of input characters.
     * @param limit Possible limit of characters for a specified document or field.
     */
    public LimitDocument( int limit ) {
        super();
        setLimit(limit);
    }

    /**
     * Get the current value for limit.
     * @return The value of <i> limit </i>.
     */
    public final int getLimit() {
        return limit;
    }

    @Override
    public void insertString( int offset, String s, AttributeSet attributeSet ) throws BadLocationException {
        if ( offset < limit ) {
            super.insertString(offset,s,attributeSet);
        }
    }

    /**
     * Setting new value for input limit without getting instantiated.
     * @param newValue New value for limit.
     */
    public final void setLimit( int newValue ) {
        this.limit = newValue;
    }

}


// Implementing to any fields, invoking from Constructor or jTextField's customize code.
jTextField.setDocument(new LimitDocument(n)); // Where n is the limit of the characters