JTextField & JPasswordField on JPanel

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A text field is a basic text control that lets the user enter a small amount of text. Generally used with GUI based data entry screens in commercial application or Applets.

Text fields are implemented in Swing by the JTextField class.

JTextField class constructors include the following:

1. JTextField(int) A text field with the specified width.
2. JTextField(String, int) A text field with the specified text and width.

Example:

The following example creates a text field having a column width of 10 units.

JTextField txt=new JTextField(10);

The JPasswordFiled class creates a text field that can use a character to obscure input.
The JPasswordField class is a subclass of JTextField class.

This class has constructor methods similar to the constructors of the JTextField class.

1. JPasswordField(imt)The int argument specifies the desired width of the column.
2. JPasswordField(String, int) The string argument contains the fields initial text, and The int argument specifies the desired width of the column.

Once a password text field is created, setEchoChar(char) method can be used to obscure input with the specified character.

The following table describes some of the methods provided by the JTextField class

Methods	Description
void setEditable(boolean) boolean isEditable()	Sets of gets whether the user can edit the text in the text field.
void setColumns(int) int getColumns()	Set or get the number of columns displayed by the text field.
void getColumnWidth()	Get the width of the text field's columns.
void setHorizontalAlignment(int) int getHorizontalAlignment()	Set or get how the text is aligned horizontally within its area. One can use JTextField.LEFT , JTextField.CENTER, and JTextField.RIGHT for aligning text in the text field.
void setEchoChar(char) char getEchoChar() (in JPasswordField)	Set or get the echo character -- the character displayed instead of the characters typed by the user.

The following example creates an object of the JPasswordField class and sets the echo character as a Bintu symbol

JPasswordField passwdtxt=new JPasswordField(10); passwdtxt.setEchoChar("*");

Example:

The following example displayed one text field and one password field.

/* =========================================================== File Name : PassDemo.java WebSite : http://javaproglang.blogspot.in/ Facebook : https://www.facebook.com/AdvanceJavaProgramming Twitter ID : https://twitter.com/AdvanceJava Created By : Bintu Chaudhary =========================================================== */ import javax.swing.*; import java.awt.event.*; public class PassDemo extends JPanel { // create an object of the JLabel class JLabel lblName; JLabel lblPasswd; // create an object of the JPassword class JTextField txtName; JPasswordField txtPasswd; public PassDemo() { lblName = new JLabel("Enter the User Name: "); txtName = new JTextField(10); lblPasswd = new JLabel("Enter the Password: "); txtPasswd = new JPasswordField(10); txtPasswd.setEchoChar('*'); // Add tooltips to the text fields txtName.setToolTipText("Enter User Name"); txtPasswd.setToolTipText("Enter Password"); //Add labels to the Panel. add(lblName); add(txtName); add(lblPasswd); add(txtPasswd); } public static void main(String[] args) { // calls the PassDemo constructor. PassDemo demo = new PassDemo(); // set the text on the frame JFrame frm = new JFrame("Password Demo"); frm.setContentPane(demo); /* setSize() method is used to specify the width and height of the frame */ frm.setSize(275,300); // To display the Frame frm.setVisible(true); WindowListener listener = new WindowAdapter() { public void windowClosing(WindowEvent winEvt) { System.exit(0); } }; // End of WindowAdaptor() method // Window listener activates the windowClosing() method frm.addWindowListener(listener); } // End of main() method } // End of class declaration

C:\>jdk1.4\bin>javac PassDemo.java
C:\>jdk1.4\bin>java PassDemo

"Output of PassDemo.class"

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Java Swing-1

JFrame	JPanel	JApplet
JButtons	JLabels	JTextFields
JPasswordField	JTextAreas	JCheckBoxes
JRadioButtons	JList	JComboBox