You can use various attributes along with your custom tags. To accept an attribute value, a custom tag class needs to implement the setter methods, identical to the JavaBean setter methods as shown below −
package com.tutorialspoint;
import javax.servlet.jsp.tagext.*;
import javax.servlet.jsp.*;
import java.io.*;
public class HelloTag extends SimpleTagSupport {
private String message;
public void setMessage(String msg) {
this.message = msg;
}
StringWriter sw = new StringWriter();
public void doTag()
throws JspException, IOException {
if (message != null) {
/* Use message from attribute */
JspWriter out = getJspContext().getOut();
out.println( message );
} else {
/* use message from the body */
getJspBody().invoke(sw);
getJspContext().getOut().println(sw.toString());
}
}
}The attribute's name is "message", so the setter method is setMessage(). Let us now add this attribute in the TLD file using the <attribute> element as follows −
<taglib> <tlib-version>1.0</tlib-version> <jsp-version>2.0</jsp-version> <short-name>Example TLD with Body</short-name> <tag> <name>Hello</name> <tag-class>com.tutorialspoint.HelloTag</tag-class> <body-content>scriptless</body-content> <attribute> <name>message</name> </attribute> </tag> </taglib>
Let us follow JSP with message attribute as follows −
<%@ taglib prefix = "ex" uri = "WEB-INF/custom.tld"%> <html> <head> <title>A sample custom tag</title> </head> <body> <ex:Hello message = "This is custom tag" /> </body> </html>
This will produce the following result −
This is custom tag