Debug JSP using Lomboz

Debug JSP using Lomboz

Ube bun (james.hu@chinacodeline.com)

Xi'an Software Co., Ltd.

September 2003

Foreword

Anyone who has JSP written experience has a hard experience in JSP debugging. Since the lack of automated debugging tools makes a lot of print statements that have to be used in the file when debugging JSP. This approach is a simple and effective means for the location of the JSP range, but how to quickly and efficiently position the internal error of the object called in the JSP. It is a bit unhappy. Because this will have to compile, release, start and stop the server, bringing great inconvenience to debugging.

The Legend of the JSP debugging tools you have obtained, don't exist on the situation currently mastering. If the reader has the hope of this information, huh, huh. But JSP debugging tools do exist, and it is free! IT's Lomboz. Download address: http://www.objectLearn.com/products/download.jsp

From a simple example, this paper describes how to use Lomboz to debug JSP. The development environment of this example is as follows:

- JDK version: 1.4.1;

- Java Ide: Eclipse 2.1;

- Lomboz: Suitable for plugins for Eclipse2.1;

- JSP / servlet container: Tomcat 4.1.18.

Introduction to Lomboz

Strictly said that Lomboz is a J2EE plugin for Eclipse. It integrates many Java application servers, J2EE components, and web applications to Eclipse, which can help Java developers use Eclipse to build, test, deploy J2EE applications. For the focus of this article, JSP debugging, it also has related support:

- Support JSP writing, including: syntax coloring and syntax check;

- Support JSP debugging.

For JSP debugging, the principle of Lomboz is to debug the Java code generated by the JSP page to be debugged. The entire debugging process is the same as the debugging process of the Java application, whether it is a JSP itself debugging or a debugging of the object called by JSP, it is seamlessly coupled to a piece.

Before you begin this article, let's first look at the Lomboz installation and configures for normal use of its JSP debugging.

Installation and configuration

Lomboz installation process is very simple, and the plugin installation process of Eclipse is very simple, the main steps are as follows:

1. Download the plugin that supports Eclipse2.1 (or other versions of Eclipse) from the Lomboz download address (http://www.objectlearn.com/products/download.jsp).

2. If the Eclipse has run, then turn it off first.

3. Extract the downloaded file to the plugins directory in the Eclipse installation directory.

4. Restart Eclipse to open "About Eclipse Platform Plug-Ins" (Help -> About Eclipse Platform -> Plug-in Details), if the Lomboz installation will appear information about it. As shown below:

Note: If you want to remove Lomboz, you only need to delete the directory of the PLUGINS directory.

5. Set the Lomboz J2EE View, open Window -> Customize Perspective, as shown in Figure Set:

The next is how to configure Lomboz to make it work. Contrary to the installation process, the configuration process is not that simple, J. The Lomboz configuration steps are as follows:

1. Configure JDK, select "Windows -> Preferences", select Lomboz, and configure the JDK. This is as follows:

2. Define the server if your server is already included in the Lomboz default server list, this step can be skipped. The Lomboz default server list can be obtained by expanding Lomboz in the previous interface, then select "Server Definitions". The following is to add Tomcat4.1.18 as an example to show how to add a server. The relevant steps are as follows:

a) Enter the servers subdirector of the Lomboz installation directory, copy one .server file (such as Tomcat410.server) and rename it to tomcat418.server.

b) Open this file to change the following location of this file:

- , change the value of the name to a name you want (such as Apache Tomcat V4.1.8), this name is used to display the list of servers in the "Server Definitions" interface;

- , where default's value is changed to Tomcat on your machine, such as D: / Program Files / Java / Tomcat-4.1.18;

- , where default is changed to any name (such as Tomcat418), this name is used to represent the default ClassPath of the Lomboz project;

- , where default value is changed to the directory where Tomcat is located, such as D: / Program Files / Java / Tomcat-4.1.18;

c) Add Jasper-Runtime.jar. By default, only 2 JAR files are included in the Tomcatx.Server file: servlet.jar and bootstrap.jar, but lack jasper-runtime.jar. And this JAR file has played a very important role in JSP debugging, so please add it. There are two ways to add JAR to a server:

method 1:

Add a line in the section of the .server file: $ {classpathvariablename} /common/lib/jasper-runtime.jar ;

Method 2: Use the "Server Definitions" interface, no more details here.

Configured servers are displayed in the "Server Definitions" form, as shown below:

Note: For Tomcat4.x servers, you need to put patch to make Lomboz work, patch download address:

http://www.sysdeo.com/

At this point, Lomboz installation and configuration has all been completed, let us create an example of "Hello World!" To experience the process of lomboz debugging JSP. Debug JSP

Create project

To use Lomboz debugging JSP, you must first create a Lomboz project. Proceed as follows:

1. Open File-> New-> Lomboz J2EE Project, create a project called debugjsp;

2. Select "Next" to enter the Lomboz Engineering Properties Select page, add web modules and servers used. Since our main task is to debug JSP, the EJB module can be empty. As shown below:

3. Choose Finish, Lomboz project is created. At this point, the file structure generated by Lomboz is shown below:

Next, we can create the JSP file you need. In this example I use the default index.jsp, change its content to: