1 Introduction

The Jakarta Pages 4.0 specification enables you to create and use custom tags in Jakarta Server Pages (JSPs). Custom tags let developers put reusable presentation behavior behind a tag name that a page author can use without repeating the Java implementation.

You can use custom JSP tag extensions to generate dynamic content in JSP pages. WebLogic Server supports the Jakarta Pages 4.0 tag-extension mechanism. For the portable rules, see the Jakarta Pages 4.0 Specification at https://jakarta.ee/specifications/pages/4.0/jakarta-server-pages-spec-4.0.html.

Note:

Jakarta Pages 4.0 retains classic and simple custom tags but removes APIs deprecated in 3.1. For a classic handler that buffers its body, return BodyTag.EVAL_BODY_BUFFERED from doStartTag(); return IterationTag.EVAL_BODY_AGAIN from doAfterBody() only when another iteration is needed, and SKIP_BODY otherwise. BodyTag.EVAL_BODY_TAG is no longer in the 4.0 API. Replace calls to JspException.getRootCause() with getCause(). For the complete 3.1-to-4.0 change list, see Appendix C.1 of the Jakarta Pages 4.0 Specification.