Java Debugging with Eclipse.doc

Java Debugging with Eclipse Learn how to use the debugger. Don’t be “too busy sawing to sharpen the saw”! Starting the program under the debugger is similar to running it. Eclipse provides two options: Use the full-service Run-Debug menu selection to use a launch configuration, or use the express Run-Debug As-Java Application selection if the default options are okay. Here you can use the latter. Create the following class: public class HelloWorld { public static void main(String[] args) { String msg = Hello World; System.out.println(msg); for(int i = 0; i5; i++){ System.out.println(debug test + i); } } Save the file and run the program. When you want to run it again, you can run it again by pressing Ctrl+F11 or by clicking Run on the toolbar. The console will print out the following: Hello worlddebug test 0debug test 1debug test 2 debug test 3debug test 4 In order to debug something, we need to add a breakpoint to the class. Add a breakpoint by double-clicking in the left margin of the text editor on the line that prints out debug test. A blue dot will appear in the left margin. Press F11 to run HelloWorld again. This time, since there is a breakpoint, Eclipse switches to the Debug perspective. The Debug perspective opens and highlights the line of code with the breakpoint. Another way of starting to debug is to make sure the source for HelloWorld is selected in the editor and select Run-Debug As-Java Application from the main menu. Eclipse will start the program, change to the Debug perspective, and suspend execution at the breakpoint. The best way of starting the debugger (especially when you have multiple projects) is to right click on the java file that contains the main program and select Run As or Debug As. I appeared to have less trouble with it running the wrong project that way. The Debug perspective includes several new views that are especially useful for debugging. First, at top left, is the Debug view (not to be confused wit