The following figure shows the mechanism of the JSP debug functionality:

Figure 2-1 JSP debug mechanism

The following points describe the flow of data in the figure:

1. Convert the JSP file to the servlet java file.
2. Create SMAP (Source MAP) that describes the mapping of the JSP file lines and the lines of the java file converted from the JSP file.
3. Use java compiler to create the class file from the java file.
4. Embed the SMAP information in the extension attribute (SourceDebugExtension attribute) of the created class file.
5. During debug, use JPDA (Java Platform Debugger Architecture) to acquire embedded SMAP from the extension information embedded in the class file in the debug tool.

Note that if an attempt to embed the SMAP information fails, the message KDJE39324-E is output.

Note

Class names when the JSP debug functionality is used

The names of the classes created during the compilation are different for the case when the JSP debug functionality is used and when the functionality is not used. For details on the class names in the JSP compilation results, see 2.5.7 Class names in JSP compilation results.