JSP2 Custom Labels

To develop a custom label in a JSP:

1 · Developing custom Label Processing classes

2 · Create a *.tid file that corresponds to a tag library for each TLD tag, with multiple tags for each tag library

3 · Using tags in JSPs

Considerations for developing Custom label classes:

1 · The custom label class should inherit a parent class Javax.servlet.jsp.tagext.SimpleTagSupport

2 · If a custom label class contains attributes, each attribute should have a corresponding Getter/setter method

3 · Overriding the Dotag () method This method is responsible for generating the contents of the page

Example:

public class Helloworldtag extends simpletagsupprt{

Overriding the Dotag () method

public void Dotag () throws jspexception,ioexception{

This.getjspcontext (). Getout (). Write ("Hello World" + New Date ())

}

}

Creating TLD Labels

TLD is the abbreviation for Tag library definition

We can copy a file template into Tomcat \webapps\examples\web_inf\jsp2 contains a jsp2-example-taglib.tld

Copy the file to the Web app's Web-inf path and make a simple modification

Example:

<!--define Labels--

Root node:

Tag

Using labels

Using labels requires two points:

1 • Tag library URL determines which label is used

2 · Label name: Determine which label to use

There are two steps to using a tag library:

1 · Import Tag Library import tag library using taglib compilation directives

<%@ taglib uri= "Http://tomcat.apache.org/debug-taglib" prefix= "MyTag"%>

URI: The URI of the tag library

Prefix: Short name

2 • Use tags; use custom tags in jsps

As we set the

<body-content>TAGDEPENDENT</body-content> define the label body as empty

We just need to call:

<mytag:log/> Prefix + label signature

JSP2 Custom Labels