For detecting clicks inside a JTextField instance, you would simply add a
mouse-listener or
mouse-adapter to your instance.

This might help:
----------------

package org.blahblah;

import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class ClickOnTextField {

public static void main(String[] args) {

JFrame frame = new JFrame();
JTextField field = new JTextField();

frame.add(field);

field.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
System.out.println("Mouse Clicked");
}
});

frame.pack();
frame.setVisible(true);
}

}

you could use this sample :

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener; 
/**
   This listener simply prints out the listener method name
   and the x- and y-coordinate of the mouse  position.
*/
public class MouseSpy implements MouseListener
{ 
   public void mousePressed(MouseEvent event)
   { 
      System.out.println("Mouse pressed. x = "
         + event.getX() + " y = " + event.getY());
   } 
   public void mouseReleased(MouseEvent event)
   { 
      System.out.println("Mouse released. x = "
         + event.getX() + " y = " + event.getY());
   } 
   public void mouseClicked(MouseEvent event)
   { 
      System.out.println("Mouse clicked. x = "
         + event.getX() + " y = " + event.getY());
   } 
   public void mouseEntered(MouseEvent event)
   { 
      System.out.println("Mouse entered. x = "
         + event.getX() + " y = " + event.getY());
   } 
   public void mouseExited(MouseEvent event)
   { 
      System.out.println("Mouse exited. x = "
         + event.getX() + " y = " + event.getY());
   }
}
ExP10_1.java

import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener; 
/**
   This programs demonstrates the use of frames to
      display mouse events
*/
public class ExP10_1 extends JFrame
{    
   public static void main(String args[])
   {
      JFrame frame = new JFrame();
      MouseSpy listener = new MouseSpy();
      frame.addMouseListener(listener);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.show();
   }
}
P10.3
ExP10_3.java

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.util.Random; 
/**
   This applet lets the user select a number of rectangles
      and displays them in random positions
*/
public class ExP10_3 extends Applet
{
   public ExP10_3 ()
   { 
      // the rectangle that the paint method draws
      box = new Rectangle(BOX_X, BOX_Y,
         BOX_WIDTH, BOX_HEIGHT); 
      // the text field for entering a number of rectangles
      final JTextField nField = new JTextField(5);

      // the button to draw the rectangle
      JButton drawButton = new JButton("Draw");     
      class DrawButtonListener implements ActionListener
      {
         public void actionPerformed(ActionEvent event)
         {
            n = Integer.parseInt(nField.getText());

            repaint();        

            // clears the text field

            nField.setText("");
         }
      } 
      ActionListener listener = new DrawButtonListener();
      drawButton.addActionListener(listener);       
      // the labels for labeling the text fields
      JLabel nLabel = new JLabel("Number of Rectangles = "); 
      // the panel for holding the user interface components
      JPanel panel = new JPanel(); 
      panel.add(nLabel);
      panel.add(nField);
      panel.add(drawButton); 
      // the frame for holding the component panel
      JFrame frame = new JFrame();
      frame.setContentPane(panel);
      frame.pack();
      frame.show();
   } 
   public void paint(Graphics g)
   {       
      Graphics2D g2 = (Graphics2D)g;

      Random generator = new Random();

      int x = 0;
      int y = 0;

      for (int i = 0; i < n; i++)
      {
         x = generator.nextInt(getWidth());
         y = generator.nextInt(getHeight());     
         box.setLocation(x, y);
         g2.draw(box);
      }
   } 
   private Rectangle box;
   private int n;
   private static final int BOX_X = 100;
   private static final int BOX_Y = 100;
   private static final int BOX_WIDTH = 20;
   private static final int BOX_HEIGHT = 30;
}
P10.5
ExP10_5.java

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField; 
/**
   This applet lets the user move a circle by specifying
      the radius and clicking on the center.
*/
public class ExP10_5 extends Applet
{
   public ExP10_5()
   { 
      // the circle that the paint method draws     
      circle = new Ellipse2D.Double(); 
      // the text fields for the radius    
      final JTextField rField = new JTextField(5);

      // add mouse press listener        
      class MousePressListener implements MouseListener
      { 
         public void mousePressed(MouseEvent event)
         { 
            double radius = Double.parseDouble(rField.getText());
            int x = event.getX();
            int y = event.getY();
            circle.setFrame(x - radius, y - radius,
               2 * radius, 2 * radius);
            repaint();
         } 
         // do-nothing methods
         public void mouseReleased(MouseEvent event) {}
         public void mouseClicked(MouseEvent event) {}
         public void mouseEntered(MouseEvent event) {}
         public void mouseExited(MouseEvent event) {}
      }

      MouseListener listener = new MousePressListener();
      addMouseListener(listener);    
      // the label for labeling the text field
      JLabel rLabel = new JLabel("Radius = "); 
      // the panel for holding the user interface components
      JPanel panel = new JPanel(); 
      panel.add(rLabel);
      panel.add(rField); 
      // the frame for holding the component panel
      JFrame frame = new JFrame();
      frame.setContentPane(panel);
      frame.pack();
     frame.show();
   } 
   public void paint(Graphics g)
   {       
      Graphics2D g2 = (Graphics2D)g;
      g2.draw(circle);
   } 
   private Ellipse2D.Double circle;
}
P10.7
Triangle.java

import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D; 
/**
   This class provides a method to draw a triangle
      from three user-specified points
*/
public class Triangle
{
   /**
      Construct a Triangle object
      @param aClick the number of clicks the user pressed
     @param aPoint the point that the user pressed on
   */
   public Triangle(int aClick, Point2D.Double[] aPoint)
   {
      clicks = aClick;
      points = aPoint;    
   }

   /**
      Draw a triangle from three user-specified points
      @param g2 the graphics context
   */
   public void draw(Graphics2D g2)
   {
      // draw circle around first point

      if (clicks == 1)
      {
         double x = points[0].getX();
         double y = points[0].getY();
         final double RADIUS = 5;
         Ellipse2D.Double smallCircle
            = new Ellipse2D.Double(x - RADIUS, y - RADIUS,
               2 * RADIUS, 2 * RADIUS);
         g2.draw(smallCircle);
      }

      // draw line connecting first and second point

      else if (clicks == 2)
      { 
         g2.draw(new Line2D.Double(points[0], points[1]));
      }

      // draw triangle

      else if (clicks >= 3)
      { 
         g2.draw(new Line2D.Double(points[0], points[1]));
         g2.draw(new Line2D.Double(points[1], points[2]));
         g2.draw(new Line2D.Double(points[2], points[0]));
      }     
   }
   private int clicks;
   private Point2D.Double[] points;  
}
ExP10_7.java

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Point2D; 
/**
   This program draws a user-specified triangle by clicking
      on three points
*/
public class ExP10_7 extends Applet
{ 
   public ExP10_7()
   { 
      clicks = 0;
      points = new Point2D.Double[MAX_CLICKS]; 
      // add mouse click  listener 
      MouseClickListener listener = new MouseClickListener();
      addMouseListener(listener);
   } 
   public void paint(Graphics g)
   { 
      Graphics2D g2 = (Graphics2D)g;

      Triangle t = new Triangle(clicks, points);
      t.draw(g2);
   }

   // implement the mouse press handler

   class MouseClickListener extends MouseAdapter
   { 
      public void mousePressed(MouseEvent event)
      { 
         if (clicks >= MAX_CLICKS) return;
         int mouseX = event.getX();
         int mouseY = event.getY();
         points[clicks] = new Point2D.Double(mouseX, mouseY);
         clicks++;
         repaint();
      }
   }    
  private int clicks;
   private Point2D.Double[] points;
   private final int MAX_CLICKS = 3;
}
P10.9
Line.java

import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D; 
/**
   This class provides a method to draw a line
      from two user-specified points
*/
public class Line
{ 
   /**
      Constructs a Line object
      @param aClick the number of clicks the user pressed
      @param aPoint the point that the user pressed on
   */
   public Line(int aClick, Point2D.Double[] aPoint)
   {
      clicks = aClick;
      points = aPoint;
   }

   /**
      Draw a line from two user-specified points
         and indicate the slope of the line at the midpoint
      @param g2 the graphics context
   */
   public void draw(Graphics2D g2)
   {
      if (clicks == 1)
      { 
         double x = points[0].getX();
         double y = points[0].getY();
         final double RADIUS = 5;
         Ellipse2D.Double smallCircle
            = new Ellipse2D.Double(x - RADIUS, y - RADIUS,
               2 * RADIUS, 2 * RADIUS);
         g2.draw(smallCircle);
      }
      else if (clicks >= 2)
      { 
         g2.draw(new Line2D.Double(points[0], points[1]));
         double x1 = points[0].getX();
         double y1 = points[0].getY();
         double x2 = points[1].getX();
         double y2 = points[1].getY();
         String message;
         if (x1 == x2)
            message = "vertical line";
         else
         { 
            double slope = (y1 - y2) / (x2 - x1);
            // note that y coordinates grow downwards
            message = "slope = " + slope;
         } 
         double mx = (x1 + x2) / 2;
         double my = (y1 + y2) / 2; 
         g2.drawString(message, (float)mx, (float)my);
      }     
   }

   private int clicks;
   private Point2D.Double[] points;  
}