What do you need for this tutorial?
- Java
- Tomcat
- Java IDE (For example Eclipse or NetBeans)
- Struts 1.x version http://struts.apache.org/download.cgi#struts1310
I’ll write another document for Struts 2.x. They are different frameworks with somehow different ideas but both are excellent choice.
For clearness it would be very simple code - I won’t use packages or other good practices. Consider this only as an introduction not a reference.
Struts programming is centered at the MVC pattern. MVC stands for Model-View-Controller, an idea to separate the business logic, application data and the presentation layer. I won’t discuss here what the advantages of using MVC architecture in web application are – just make a fast search, there is plenty of information out there.
Let’s start with creating a new project. Our web application would ask visitors for a name and redirect them to a Hi! page. At part 2 it won’t like some of the visitors and will return back them with an error message.
Here is my directory and file structure for Struts1Example project:
Struts1Example src NameAction.java NameActionForm.java webroot WEB-INF classes lib struts-config.xml web.xml ask.jsp greet.jsp
Lets start with writing our ActionForm – I’ll name the class NameActionForm. It would be very plain – only one field and a setter-getter pair. Here is the code:
NameActionForm.java
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
public class NameActionForm extends ActionForm {
private String name = null;
public void reset(ActionMapping mapping,
HttpServletRequest request) {
this.name = null;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
And our action:
NameAction.java
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public class NameAction extends Action {
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) {
return mapping.findForward("success");
}
}
In Struts the Action class goal is to process a request, do the logic and pass a forward object (ActionForward). Our Action is very simple – it is doing nothing, just passes our forward object. The “success” forward is defined in our struts-config.xml.
We will have two jsp files – ask.jsp and greet.jsp. In ask.jsp we will ask visitors for a name.
ask.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" %> <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %> <html:html> <head> <title>Say Hi!</title> </head> <body> <html:form action="nameAction"> What's your name? <html:text property="name"></html:text> <html:submit>Send!</html:submit> </html:form> </body> </html:html>
greet.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" %> <%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %> <%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %> <html:html> <head> <title>Say Hi!</title> </head> <body> Hi, <bean:write name="nameForm" property="name" /> </body> </html:html>
And now the cool part – web.xml
web.xml
<?xml version="1.0"?>
<web-app>
<display-name>Struts 1x Example</display-name>
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>
org.apache.struts.action.ActionServlet
</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>
/WEB-INF/struts-config.xml
</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
And our struts configuration – struts-config.xml
struts-config.xml
<?xml version="1.0" ?>
<struts-config>
<form-beans>
<form-bean
name="nameForm"
type="NameActionForm"/>
</form-beans>
<global-forwards>
<forward
name="/nameAction"
path="/nameAction.do"/>
</global-forwards>
<action-mappings>
<action path="/nameAction"
type="NameAction"
input="ask.jsp"
name="nameForm" >
<forward name="success"
path="/greet.jsp"/>
<forward name="failure"
path="/ask.jsp"/>
</action>
</action-mappings>
</struts-config>
struts-config.xml is used to initialize Struts. It describes the action mappings for the project and must be placed in the WEB-INF directory. We have a form-bean tag describing our NameActionForm and an action-mapping for our NameAction.
This is our base code. In some future post I’ll add field validation, error handling and some other good stuff.
