Custom JSP tag - How do I get the body of the tag?
I have a custom jsp tag like this:
<a:customtag>
The body of the custom t开发者_StackOverflowag...
More lines of the body...
</a:customtag>
In the custom tag, how can I get the text of what the body is?
It's complicated because there are two mechanisms.
If you're extending SimpleTagSupport, you get getJspBody() method. It returns a JspFragment that you can invoke(Writer writer) to have the body content written to the writer.
You should use SimpleTagSupport unless you have a specific reason to use BodyTagSupport (like legacy tag support) as it is - well - simpler.
If you are using classic tags, you extend BodyTagSupport and so get access to a getBodyContent() method. That gets you a BodyContent object that you can retrieve the body content from.
If you are using a custom tag with jsp 2.0 approach, you can do it as:
make-h1.tag
<%@tag description="Make me H1 " pageEncoding="UTF-8"%>
<h1><jsp:doBody/></h1>
Use it in JSP as:
<%@ taglib prefix="t" tagdir="/WEB-INF/tags"%>
<t:make-h1>An important head line </t:make-h1>
To expand on Brabster's answer, I've used SimpleTagSupport.getJspBody()
to write the JspFragment
to an internal StringWriter
for inspection and manipulation:
public class CustomTag extends SimpleTagSupport {
@Override public void doTag() throws JspException, IOException {
final JspWriter jspWriter = getJspContext().getOut();
final StringWriter stringWriter = new StringWriter();
final StringBuffer bodyContent = new StringBuffer();
// Execute the tag's body into an internal writer
getJspBody().invoke(stringWriter);
// (Do stuff with stringWriter..)
bodyContent.append("<div class='custom-div'>");
bodyContent.append(stringWriter.getBuffer());
bodyContent.append("</div>");
// Output to the JSP writer
jspWriter.write(bodyContent.toString());
}
}
}
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