Description
The JSP Action Tags are used to perform a some specific action task. There are many JSP action tags. The actions are used during request processing where as directive tags are used for translation phase. For controlling the behavior of the servlet engine, the JSP action tags are used as constructs in XML syntax.By using this action tags, a file can be inserted dynamically. To reuse JAVABean components, forward the request and response to another page, or create HTML for Java module.
Table
| Tags | Description |
|---|---|
| Jsp:forward | Forwards the request and response to other sources |
| Jsp:include | includes other resources |
| Jsp:element | To define XML elements at runtime. |
| Jsp:getproperty | Prints the property values of the bean |
| Jsp:useBean | Creates bean object |
| Jsp:plugin | Embeds another resource |
| Jsp:param | Set the parameter values. It is used mostly in forward and include pages. |
| Jsp:setProperty | Sets the property estimations in bean objects. |
| Jsp:attribute | Defines XML elements attributes dynamically. |
| Jsp:body | Defines XML elements body. |
Description
The functionality forward action tag is to forward the request and response to another resource like html or JSP.
Syntax:
<jsp:forward page="relativeURL | <%= expression %>" />
//jsp:forwar tag with parameters
<jsp:forward page="relativeURL | <%= expression %>"> <jsp:param name="parametername" value="parametervalue | <%=expression%>" />
</jsp:forward>
Example
Below is an example to jsp:forward tag.
forwardtag.jsp
[html]<html>
<body>
<h2>this is page,here included another file that is printdate.jsp</h2>
<jsp:forward page="printdate.jsp">
<jsp:param name="name" value="WWW.SPLESSONS.COM" />
</jsp:forward>
</body>
</html>
[/html]
Hete used JSP forward tag for the printdate.jsp .
printdate.jsp
[html]
<html>
<body>
<% out.print("Today is:"+java.util.Calendar.getInstance().getTime()); %>
<%= request.getParameter("name") %>
</body>
</html>
[/html]
request.getParameter() method is used to get the name from forwardtag.jsp.
Output:
While compiling the code forwardtag.jsp file should be in active mode,output will be as follows with current time followed by parameter name.
Description
The include action tag is utilized to incorporate the substance of the other asset like JSP, HTML, Servlet.JSP include action tag incorporates the substance at solicitation time so its better for element pages since it is utilized for future changes.
Syntax
<jsp:include page="relativeURL | <%= expression %>" />
//jsp:include action tag with parameter
<jsp:include page="relativeURL | <%= expression %>">
<jsp:param name="parametername" value="parametervalue | <%=expression%>" />
</jsp:include>
Description
The useBean action tag is used to instantiate a bean class. When bean object is not created, it instantiates the bean. If bean object is available already, it doesn't rely on upon the bean extent of the object.
Syntax
<jsp:useBean id= "instanceName" scope= "page | request | session | application" class= "packageName.className" type= "packageName.className" beanName="packageName.className | <%= expression >" >
</jsp:useBean>
Example
Below is an example to usebean action tag.
useBean.jsp
[java]
<jsp:useBean id="obj" class="com.Question">
<%
String name = obj.message();
out.println("Enter a name");
(
<h2>your name is "+name+"</h2>
");
%>
</jsp:useBean>
[/java]
Question.java
[java]
package com;
public class Question
{
public String message(){
String name = "john";
return name;
}
}
[/java]
Output:
Below is an output with name that was provided in .java file.
Description
The jsp: setProperty activity tag is utilized to set property estimations in a bean utilizing setter method. The setProperty uses java bean for the development of web application.
Syntax
<jsp:setProperty name="instanceOfBean" property= "*" |
property="propertyName" param="parameterName" |
property="propertyName" value="{ string | <%= expression %>}"
/>
Description
The jsp: getProperty action tag is utilized to get property values in a bean using getter method. This getProperty is used for web application with java bean.
Syntax
<jsp:getProperty name="instanceOfBean" property="propertyName" />
Example
Below is an example to set and get properties.
setgetproperty.html
[html]
<form action="process1.jsp" method="post">
Name:<input type="text" name="name">
Password:<input type="password" name="password">
Email:<input type="text" name="email">
<input type="submit" value="register">
</form>
[/html]
Here just created three text boxes for Name, Password, Email and submit button.
process1.jsp
[html]<jsp:useBean id="u" class="User"></jsp:useBean>
<jsp:setProperty property="*" name="u"/>
Record:
<jsp:getProperty property="name" name="u"/>
<jsp:getProperty property="password" name="u"/>
<jsp:getProperty property="email" name="u" />
[/html]
Here get property on the name, password, email.
User.java
[java]public class User {
private String name,password,email;
//setters and getters
} [/java]
Output
Output will be as follows with three text fields and one register button.
Description
The plugin action is utilized to insert the applet or bean into a JSP page, This tag is used when there is a need of plugin to run a Bean class or applet.
Syntax
<jsp: plugin type = "bean" code = "nameOfClassFile"
codebase = "directoryNameOfClassFile">
</jsp: plugin>
Description
The element tags are utilized to define XML elements at runtime.
Syntax
<jsp:element name="xmlElement"></jsp:element>
<jsp:attribute name="xmlAttribute"></jsp:attribute>
Description
jsp:text action tag is utilized to write the text template in JSP pages.The body template contains only text and EL expressions.
<jsp: text> Template data </jsp: text>
Key Points
- The jsp:plugin action tag is used to embed applet in the JSP file.
- Action tags to control the flow between the pages.
- jsp:fallback will be used in jsp:plugin to scan the message.