How to exclude the submit action from a list of parameters in Struts 2?

Question

I'm trying to exclude a submit action from a parameter list.

The following is the action class:

@Namespace("/admin_side")
@ResultPath("/WEB-INF/content")
@InterceptorRefs({
    @InterceptorRef(value="validation", params={"excludeMethods", "test"}),
    @InterceptorRef(value="params", params={"excludeParams", "action:postAction"})})
public final class TestAction extends ActionSupport implements Serializable, ValidationAware
{
    private static final long serialVersionUID = 1L;
    private static final String SUCCESS = "success";

    private String name;

    @Action(value = "test", results = {
    @Result(name="success", location="Test.jsp"),
    @Result(name = "input", location = "Test.jsp")})
    public String test() throws Exception
    {
        System.out.println("name = "+name);
        return SUCCESS;
    }

    @Action(value = "postAction", results = {
    @Result(name="success", location="Test.jsp"),
    @Result(name = "input", location = "Test.jsp")})
    public String postAction()
    {
        System.out.println("Post invoked");
        System.out.println("name = "+name);
        return SUCCESS;
    }

    @RequiredStringValidator(type= ValidatorType.FIELD, message = "The name is required.")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public void validate()
    {
        if(!hasErrors()&&name.length()<2)
        {
            addFieldError("name", "The name must compose of 2 letters.");
        }
    }
}

The Test.jsp page:

<s:form namespace="/admin_side" action="test" validate="true">
    <s:textfield id="name" name="name" label="Name"/>
    <s:submit id="btnSubmit" name="btnSubmit" value="Submit" action="postAction"/>
</s:form>

The generated HTML code for <s:submit> would be like as follows.

<input type="submit" id="btnSubmit" name="action:postAction" value="Submit"/>

---

The @InterceptorRef above the class:

@InterceptorRef(value="params", params={"excludeParams", "action:postAction"})

doesn't seem to work. The method postAction() is never invoked causing the following warning to be issued.

Dec 24, 2013 10:49:16 PM com.opensymphony.xwork2.interceptor.ParametersInterceptor warn WARNING: Parameter [action:postAction] is on the excludeParams list of patterns!

---

In the struts.properties file, I have the following properties until now.

struts.enable.DynamicMethodInvocation=false
struts.devMode=false
struts.ui.theme=simple

struts.convention.package.locators=actions
struts.convention.action.suffix=Controller
struts.convention.action.mapAllMatches=true

struts.convention.result.path=/WEB-INF/content //No need. It is the default.
struts.mapper.action.prefix.enabled=true

I'm using Struts 2.3.16.

---

Why doesn't it exclude the submit button's parameter? How to invoke the postAction() method, when <s:submit> is clicked?

Answer 1

Why doesn't it exclude the submit button's parameter?

Because this parameter is in the excludeParams list of the params interceptor in the defaultStack which your action is referenced by default.

How to invoke the postAction() method, when <s:submit> is clicked?

In this question you ask how to invoke a method (not an action). The difference between the action and method the first is mapped to a specified URL using a namespace and action name. So, to invoke a method other than an action you should turn DMI on. Struts, since 2.3.16 turned off this option. The following configuration constant to use in struts.xml:

<constant name="struts.enable.DynamicMethodInvocation" value="true"/>

and use a method attribute instead of action attribute.

<s:form namespace="/admin_side" action="test">
  <s:submit value="Submit" method="postAction"/>
</s:form> 

as I already told in this answer.

If you don't want to use DMI, then you have an option to enable action: prefix to the parameter

<constant name="struts.mapper.action.prefix.enabled" value="true"/>

and use an action mapped to the method postAction

<s:form namespace="/admin_side" action="test">
  <s:submit value="Submit" action="postAction"/>
</s:form> 

and use annotation without params.excludeParams.

@InterceptorRef(value="defaultStack" params={"validation.excludeMethods", "test"})

The warning that action:postAction parameter is on exclude list still persist, but it appears only if the struts.devMode=true. You shouldn't worry about it because it warns all parameters from the excludeParams list that passed through. To turn off devMode you should set

<constant name="struts.devMode" value="false" />