I'm new in struts so I what know the meaning of "/" in namespace of package.
i.e.
when I put namespace as "/Home"
<package name="base" namespace="/Home" extends="struts-default">
<action name="HelloWorld" class="controller.HelloWorld">
<result>/message.jsp</result>
</action>
</package>
and type this Url : "localhost:8080/Struts2Example/Home/HelloWorld.action" on browser , then page opens.
but when I change the namespace to "Home" then it gives "Error : 404".
So what's this "/" means ?
From Struts Manual http://download.oracle.com/otn_hosted_doc/jdeveloper/j2ee101302/working_with_struts/f1_struts_ide/f1_strutsconfigactionmappings.html
and here
http://struts.apache.org/release/2.1.x/docs/namespace-configuration.html
The request URI path which, when received by the Struts servlet action controller, invokes the action mapping. The path name is a relative path and must include the forward slash (/).
Here's some 101 on name spaces.
The first thing you need to keep in mind is that namespace is not a file path.
Coming to what a namespace does:
What happens is that when a user hits a request to access a struts web application, this url is splitted into hostname, port name, servlet context name, namespace (if any) and the struts action.
Ex. : localhost:8080/myapp/discountModule/getPrice.action
Namespace divides the action configuration into logical modules.
For example if the URL /foo/myfoo/myfooaction.action is requested, the framework will first look for namespace /foo/myfoo. If the action does not exist at /foo/myfoo, the search will immediately fall back to the default namespace "". The framework will not parse the namespace into a series of "folders".
So when do we use names Spaces
Namespace is very useful in large web application that need to seprated into small domains or modules. Example lets say you are managing a shopping cart backend and this has 4 main section - ADMIN, ORDERS, SALES & REFUNDS
As described earlier, namespace is defined inside the tag using namespace attribute. To define these four domain, four tag will be defined with their namespace specification as follows:
Ex - localhost:8080/shoppingCart/admin/doSomeAdmin.action
REMEBER - IT IS NOT MANADTORY TO USE A NAMESPACE.
Struts documentation has few more examples - http://struts.apache.org/release/2.1.x/docs/namespace-configuration.html
Adding to user1428716
only "/" define the root name space.
<package name="base" namespace="/e" extends="struts-default">
<action name="HelloWorld" class="controller.HelloWorld">
<result>/message.jsp</result>
</action>
</package>
root is : "http://localhost:8080/Struts2Example/"
so the url is "http://localhost:8080/Struts2Example/HelloWorld.action"
and when we mention "/namespacename" then it means "~root/namespaceName/your.action"
Related
I have been searching web for hours, and I can't find answer to a simple question in Struts 2. Basically, I have the following action in Struts 1 which is a simple forward, and I want to reproduce the same in Struts 2:
<action path="/az/api/v22/my-tenants" forward="/components/c/apis/v22/my-tenants.jsp">
</action>
I could write an action class to do this, but I think Struts2 has to have some way of doing this without having to write an action class since it is is a simple redirection.
Create actionless result in the struts.xml
struts.xml:
<package name="v22" namespace="/az/api/v22" extends="struts-default">
<action name="my-tenants">
<result>/components/c/apis/v22/my-tenants.jsp</result>
</action>
</package>
This configuration defines a package with namespace /az/api/v22 and action name my-tenants. So if you use path /az/api/v22/my-tenants it will be mapped to the action config above, because default action mapper is using namespace and action name together to get the action config.
There's no class attribute in the action tag, and it uses class ActionSupport instead. This class is configured by default in struts-default package.
In the result it's enough to define the location of the JSP, because struts2 defaults are using a dispatcher that forwards to JSP, and it's using "success" result code by default in the result config which is returned by default by ActionSupport class.
From the Apache documentation:
While the prefix appears in the browser URI, the tags are "namespace
aware", so the namespace prefix does not need to be embedded in forms
and links.
struts.xml:
<package name="testpkg" namespace="/test" extends="struts-default">
<action name="doTest" class="otes.test.TestAction">
<result>/success.jsp</result>
</action>
</package>
index.jsp: (http://localhost:8080/nsdemo/)
<h2>Using HTML tags:</h2>
<h3>doTest without namespace</h3> <!-- 404 error -->
<h3>doTest with namespace</h3> <!-- works -->
<h2>Using Struts2 tags:</h2>
<h3><s:a href="doTest">doTest without namespace (s:a href)</s:a></h3> <!-- 404 error -->
<h3><s:a href="test/doTest">doTest with namespace (s:a href)</s:a></h3> <!-- works -->
<!-- 404 error -->
<s:url action="doTest" var="myAction" />
<h3><s:a href="%{myAction}">doTest without namespace (s:url action)</s:a></h3>
<!-- works -->
<s:url action="test/doTest" var="myAction" />
<h3><s:a href="%{myAction}">doTest with namespace (s:url action)</s:a></h3>
Does this mean I really have to specify the namespace in my forms and links?
(I am using Struts 2.3.20 if that matters.)
First of all: the tags referred in the docs are Struts2 tags (e.g. <s:url>, <s:a>).
And namespace aware means that if you already executed some action in particular namespace then in the JSP you don't need to prefix S2 links and forms with the current namespace.
E.g. if you have this package configuration:
<package name="testpkg" namespace="/test" extends="struts-default">
<action name="index">/index.jsp</action>
<action name="doTest" class="otes.test.TestAction">
<result>/success.jsp</result>
</action>
</package>
and executed the index action (http://localhost/app/test/index.action). Then in index.jsp you can write
<s:a action="doTest">test</s:a>
and that url will take you to the same namespace.
If you want to change namespace there is namespace attribute in some tags that you can use.
E.g. you are in some page (http://localhost/app/index.action) - note no namespace in url, then following link will execute doTest in /test namespace.
<s:a action="doTest" namespace="/test">test</s:a>
BTW don't add action extension to actions in S2 tags.
This is wrong:
<s:form action="doTest.action">
This is correct:
<s:form action="doTest">
The rule is simple: if you defined a package with the namespace attribute then its actions belong to this namespace. And when you use url or a, or form tags you should specify a namespace attribute along with action name which is in action attribute. If you specify both parameters Struts can easy map your URL to the action from the package with namespace. Don't use action extension in these attributes. Struts is using UrlHelper class to build the url and if it can't find the action mapping it will return the string as is. Also if you are using href attribute then Url helper is not involved, so the string remains as is.
This code should work:
<s:url namespace="/test" action="doTest" var="myAction" />
<h2><s:a href="%{#myAction}">doTest with href (s:url action)</s:a></h2>
<h2><s:a namespace="/test" action="doTest">doTest with namespace and action (s:url action)</s:a></h2>
This is my package structure in Struts.xml file
<package name="default" namespace="/" extends="struts-default">
<!-- Default action name <default-action-ref name="Index" /> -->
<action name="Index" method="index"
class="com.convergent.struts2.actions.UserAction">
<result name="success" type="dispatcher">/WEB-INF/html/index.jsp</result>
</action>
</package>
<include file="struts-admin.xml"></include>
My Index.jsp is access through this url
http://localhost:8888/Index
In Index page there is hyper link that redirect that user to Setting Page. Setting action is in the 'Admin' namespace so it is access as:
Setting
In setting page there is a hyper link to redirect the user to index.jsp page. action is called like this:
go back
As you can seen 'Index' action is in the default package having namespace '/'. So to handle this action namespace is changed and user is redirected to the index.jsp page. My problem is that although user is redirected to index.jsp page but the web url looks like
http://localhost:8888/Admin/Index
I want this url to
http://localhost:8888/Index
I don't know how to solve this problem. can anyone suggest me ?
"As you can see 'Index' action is in the default name space." - no it is in the default package and the namespace "/".
Advice: 1) Don't create namespaces without leading a leading '/', it generally isn't want you want. For basic use of namespaces see http://struts.apache.org/release/2.1.x/docs/namespace-configuration.html although that page does not cover the creation of namespaces without a leading slash, and the interesting behaviour you've experienced.
2) Use the namespace attribute of the struts2 url tag. When using Struts the tag reference is your friend: http://struts.apache.org/release/2.3.x/docs/tag-reference.html
As Roman mentioned, using the anchor tag will be a touch more straight forward.
Using just the url tag you would have:
go back
When this is a bit clearer:
<s:a namespace="/" action="Back">go back</s:a>
To solve this problem what i do rather than redirecting the user to index.jsp I first redirect the user to another action like this
go back
To handle this action mapping in struts-admin.xml is:
<action name="Back">
<result name="success" type="redirectAction">
<param name="namespace">/</param>
<param name="actionName">Index</param>
</result>
</action>
This way I solve the problem.
I'm working on a Struts application.
In order to edit the struts-config.xml file, I think I have to add an attribute - scope, in the action tag. I'm not sure about its meaning, or its usage.
<action path="/WetsVpnSwapTraffic"
type="com.kpn.bop.web.action.vpn.wets.WetsVpnSwapTraffic"
scope="request"
name="WetsVpnSwapTrafficForm"
roles="bop_wetsvpn_migrate"
validate="false">
<forward name="success" path="/WetsVpnSwapTrafficValidate.do"/>
<forward name="failure" path="/WetsVpnList.do"/>
</action>
Can anyone explain me if I have to put this attribute?
The attribute scope is used to define the scope (life of the object, the form) of the object action form that used in that action configuration.
There's also different scopes, page, request, session, application. That's all from servlet specs. If you specify the scope of request that you want the form object is available during servlet http request.
You can check this reference to determine how to use scopes.
There's also link to action mapping configuration.
It determines if the ActionForm is in the request or session.
First off, please forgive me for my lack of understanding... I'm still learning :)
I have 2 packages in my struts.xml that extend a base package and I want to be able to access them by typing in my browser something similar to http://site.com/application/1/ThisAction.action and /application/2/ThisAction.action (examples).
I created two directories in my webapp folder, named '1' and '2' and I am able to navigate to both packages using the urls above. What I want to do is actually put my jsps within the jsp directory, instead of webapps. so instead of my two folders residing inside /webapp, they should reside in /webapp/jsp/.
I tried changing the namespace of the two packages to something like /1/jsp/ instead of simply '/1', but i get nothing. It just keeps telling me there is no action mapped to that action name.
Does anyone have any insight on how I can accomplish this? Google's not giving me a lot of help, but it may just be that I'm not searching for the right thing.
Here's a quick sample of what I'm referring to:
<struts>
<!-- Base-->
<package name="base" extends="struts-default" abstract = "true" namespace="/base">
<global-results>
<result name="cancel" type="redirectAction">CancelAction</result>
<result name="close">closewindow.jsp</result>
<result name="error">/jsp/wizard/GeneralError.jsp</result>
</global-results>
</package>
<package name="1" extends="base" namespace="/1">
In Struts 2 you do not need to put your JSP's in various folders according to the URL that you use to access them. Rather the package and the action comes together to create the URL and the result will determine the next view. So you start by writing your action:
public class MyActionClass ...{
...
public String actionMethod() {
//Your action code here
return SUCCESS;
}
}
Next you will create an entry in struts.xml that points to this action.
<package name="default" extends="struts-default">
<!--Interceptors, Global Results etc.-->
<action name="myaction" class="my.package.MyActionClass" method="actionMethod">
<result>/WEB-INF/path/to/yourpage.jsp</result>
</action>
...
</package>
Now, to access this action in the default package you simply use the URL: http://yourserver/myaction.action.
If you create a second package with a different name like this:
<package name="2" extends="default" namespace="/2" >
<action name="myaction" class="my.package.MyActionClass" method="actionMethod">
<result>/WEB-INF/path/to/yourpage.jsp</result>
</action>
...
</package>
Then you can access that action with the URL: http://yourserver/2/myaction.action.
So you can go ahead and put your JSP in the directory called jsp if you wish and you only have to modify the result to point to the correct place.