Starting a Local Debugging Session

Local debugging is the process of debugging a program that is running on the same computer as the IDE. The IDE starts the debugger, then runs the application inside the debugger. When you start a debugging session, the IDE automatically opens the debugger windows and prints debugger output to the Output window.

Debugging the Main Project

All of the debugging commands in the Run menu are run on the main project. No matter what file or project is selected in the Projects window or Source Editor, these commands begin the debugging session in the main class of the main project.

Command	Shortcut	Description
Run > Debug Main Project	Ctrl-F5 or	Runs the program until it reaches a breakpoint or exception or until the program terminates normally.
Run > Step Into	F7 or	Runs the program to the first line after the main routine and pauses execution before any changes have been made to the state of the program.
Run > Run to Cursor	F4 or	Runs the program to the cursor location in the Source Editor and pauses the program. The file you have selected in the Source Editor must be called from the main class of the main project.

Debugging an Individual Project

• Right-click the project in the Projects window and choose Debug Project.

The IDE runs the project in the debugger until execution stops or a breakpoint is reached.

Debugging an Individual File

• Select any runnable file in the Projects window and choose Run > Run File > Debug my_file.

The IDE runs the file in the debugger until execution stops or a breakpoint is reached.

 

Starting a Remote Debugging Session

Remote debugging is the process of debugging an application that is running on a different computer. This technique is useful when you are developing an application that runs on a web server or on a different environment than the computer on which you are developing the application.

To start a remote debugging session:

1. On the computer where the application is located, start the application in debugging mode. See your VM documentation for instructions on starting an application in debugging mode. For the Sun Microsystems Java Virtual Machine, the options can be found at:
   http://java.sun.com/products/jpda/doc/conninv.html
2. On the computer where the IDE is running, open the projects that contain the source for the application.
3. Choose Run > Attach Debugger.
4. Select the connector type and enter any required process information, then click OK. See your VM documentation for information about the connectors it provides.

About Debugging and Testing Web Applications

At the end of the development cycle, you need to debug and test your web application. The IDE has a number of features that help you to do so. The following are the most important ones:

• Detection of syntax problems in JSP files during compilation.
• Viewing the translated servlet after deployment.
• JUnit testing.
• Using the debugger to debug web applications, JSP files, and servlets.
• Using the profiler to profile web application performance and check for memory leaks.
• Monitoring by means of the HTTP Monitor. When you run web applications, JSP files, or servlets, the HTTP Monitor can gather data about HTTP requests that the servlet engine processes. For each HTTP request that the engine processes, the monitor records data about the incoming request, the data states maintained on the server, and the servlet context. You can view data, store data for future sessions, and replay and edit previous requests.
• Writing a target to debug and test free-form web projects.

Debugging a Web Application

You can use the Sun Microsystems JPDA debugger from the IDE to debug web applications, servlets, and JSP files. Just as with Java programs, the IDE enables you to set new watches, evaluate a variable by holding the cursor over the variable, and set breakpoints in JSP files, JSP documents, and JSP segments. A tag file is debugged when you debug the JSP file that references it.

The method that you use to start a debugging session depends on the type of web component that you want to debug.

To debug a web application:

1. Set breakpoints and watches in the web application's JSP files, servlets, and other source files.
2. If necessary, specify request parameters in the JSP files and servlets.
3. Right-click the project node in the Projects window and choose Debug Project from the pop-up menu.

To debug a JSP file:

1. Set breakpoints and watches in the JSP file and, optionally, its tag files.
2. If necessary, specify request parameters in the JSP file.
3. Right-click the JSP file's node and choose Debug File. Optionally, choose Run > Run File > Debug file.jsp (Ctrl-Shift-F5) from the main menu.

When you change a JSP file while in a debugging session, you do not need to start a new debugging session. Just reload the page.

To debug a servlet:

1. Set breakpoints and watches in the servlet.
2. If necessary, specify request parameters in the servlet.

Right-click the servlet's node and choose Debug File. Optionally, choose Run > Run File > Debug file.java (Ctrl-Shift-F5) from the main menu.

-- Wagner R. Santos