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How to Remove Automatic Selection on Text Field when I Start to run my Java Program

Good Day! Why whenever I start my Java Program, the JtextField is always selected even I am not selecting it. Is there any way I can remove it?
Kindly see the picture. Thanks!
The encircled JTextField is what I am talking about

Note, what you refer to by "selected" is called "focus" in Swing. That said, there's no such thing as "no component has the focus".
The best thing you can do is give the focus to a non-input element, like the "Information" title field.
Assuming that is a JLabel, you'd do something like
JLabel informationHeaderLabel = new JLabel("Information");
// ... layout etc
informationLabel.requestFocusInWindow();
There's a tutorial on the Swing focus subsystem.

JAVA .. validating input when textfields lose focus

I'm (a beginner) creating a sign up form in netbeans. What I really want to happen is, a JOptionPane will appear when the textfield loses focus if a users input is wrong . I've been searching for the answer on the internet for the whole day but the answers I find don't satisfy me.

You need to implement a FocusListener, add it to your textField and in your focusLost implementation of the FocusListener you need to do whatever you want it to do when focus is lost.
http://docs.oracle.com/javase/tutorial/uiswing/events/focuslistener.html
I'm not experienced with NetBeans but I'm assuming you use the graphical tool to create your form. I think you will need to start coding to implement the listener.

You should be using an InputVerifier for this type of validation.

What is the best way to make clickable text in java?

This is for an application so I don't want a hyperlink. I first tried using a Jbutton without all of border/background stuff and then hooking up an actionListener to it but I couldn't get it to the point where I thought it looked nice. I also tried using a JLabel and hooking up a mouse listener to that but I also couldn't get it to look right.
Basically I would like a way using swing to make a button exactly like a url link in an application. What is the standard way of doing this?

but I couldn't get it to the point where I thought it looked nice
You might want to go into greater detail on just what "looked nice" means. I can see you solving this by either a JButton or a JLabel, but the key is perhaps not to look for another solution but to play with the settings of the button or the label til they look nice. If you can't find a nice solution, then post your code (an SSCCE would work best of all) and perhaps we can help you.

that isn't answer to your question but are you tried to add ButtonModel to your JButton example here

It is a rather heavy hammer to use, but SwingX has a JXHyperLink control that is probably exactly what you want. The source is at http://java.net/projects/swingx/sources/svn/content/trunk/swingx-core/src/main/java/org/jdesktop/swingx/JXHyperlink.java?rev=4027 and you can see an article about it at http://www.javalobby.org/java/forums/t18617.html.
It is old, but SwingX continues to do good things.

It's you're trying to make a desktop application which looks like HTML inside a browser, you might try using some of the richer Swing text components in a read-only mode. You could use a mouse-listener to map X/Y clicks to a particular character of text, and then cause an action to occur on that basis.

How to increase the height of Textarea in jtable dynamically

I have a standalone application in which I have a Jtable. In my table, when I type the text, the height of the Textarea should increase dynamically with the text. How can I do this?
Can someone help me with an example how to do this?
Thanking You
Chaithanya

It wasn't clear from your question - are you using a JTextArea or a TextArea? The reason it's ambiguous is people generally don't mix and match the light and heavy-weight frameworks (e.g. put awt components within a swing component).
If it's a JTextArea, I think your best bet is probably to use a DocumentListener.
DocumentListener myListener = ??;
JTextArea myArea = ??;
myArea.getDocument().addDocumentListener(myListener);
http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html#doclisteners
I think what you'll need to do is listen for changes, and whenever something is added to the file, call the getLineCount() method, and compare it with the getRows() method. If it's broken the threshold, then use a setRows() call to increase the number of rows.
Will probably need to file some sort of UI change, especially to propagate up to the JTable.

Linking a variable and a text box in Java

How can I link a variable and a text box in the simplest possible way?
I.e. If the user changes the text box contents the variable changes and if the program changes the variable the text in the text box changes.
N.B. I'm using the swing and awt libraries.
Thanks in advance.

put your variable in an Observable wrapper. It will tell the JTextfield about the changes.
add a DocumentListener to the field.getDocument() to tell your variable that its value should change.

If you find yourself doing lots of custom UI/Bean binding, consider JGoodies Binding.
Using Observable or a DocumentListener is ok.
For more advanced stuff, you may want to look at PropertyEditor, BeanDescriptor, BeanInfo and Customizer classes/interfaces.

I would simply add an ActionListener to the JTextField to listen to changes. When it's time to update the field, make changes to the JTextField and be prepared to ignore the events it fires off as a result.
The other option is to edit the field's Document directly, and add a DocumentListener to listen for changes. I find working with Documents to be more complex than needed, however.