Tricks/Solutions

How to set shortcut keys to menu-items in java easy way:

JMenuItem mi=new JMenuItem("Item");

mi.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_I, ActionEvent.CTRL_MASK));

JMenu menu=new JMenu("Menu");

menu.add(mi);

where, VK_I=the key which is to used as shortcut key

           CTRL_MASK=which key is to pressed with shortcut key

Java Database Connectivity to MySQL Server Database easyway:

        MySQL server database connectivity a connector , that can be download from internet. A jar file is there to download as JConnector in various versions.I use mysql-connector-java-5.1.8-bin.jar. Extract that jar file where your database connectivity program saved. This jar file contains drivers that are required to connect to MySQL database.
        Database connectivity code is as follows:

Class.forName("com.mysql.jdbc.Driver").newInstance();             
con = DriverManager.getConnection("jdbc:mysql://localhost/ database_name","root","MySQL root password"); 

Click here: Example of java MySQL database connectivity

How to create a jar file of application created in java :

Step 1:- Copy all the class files & file & folders required for application in folder

Step 2:- Setting environmental variable

             Open command prompt. Go to folder where your application exists.

             Set environmental variable by executing following command

             set path="c:/program files/ java/ jdk 1.5/ bin"; 

where path string is path of jdk/bin installed in your PC

Step 3:- Creating a jar file:

             Execute following command at command prompt.

             jar cvf application_name.jar *.*

             press enter. Your jar file is created.

Step 4:- Now open that jar file with winrar.

             Open manifest.mf file in notepad. manifest.mf file exists in folder META-INF folder. Write following line in last of file

             Main-Class: Name of first opening frame main class file of your application without .class extension without extension, for example password screen.

             Example, Main-Class: password_screen

             save changes to file.

                Double click on jar file. See what happens.