Question

I am new in struts and learning it. My question is how struts map request parameter with action instance variable. For Example i have one login form that take username and password. Now it sends request to LoginAction. How this action class will get username in username instance variabel and password in password variable. In servlet we use request.getParameter() method and assign value to particular variable.

Answer 1

in struts2 we use Interceptor, in this case struts2 will set the params for you with param interceptor, you just have to config your interceptor stack (or you just use the default-stack). here is the link to Interceptor, if you are very fresh in struts2, just use the default configuration and take a feel.

example:

<s:form action="my-action">
  <s:textfield name="myField"/>
  <s:submit/>
</s:form>

and

action class:

public class MyActionClass extends ActionSupport{
  private String myField; // getter and setter
  public String execute() throws Exception{
    return "success";
  }
}

configuration:

<package name="default" extends="struts-default">
  <action name="my-action" class="MyActionClass">
    <result>success.jsp</result>
  </action>
</package>

in this case myField will be set automatically by interceptor.