We Keep Coding

Changing httpservletrequest to restcontroller in Spring

I have a servlet class which has a method "process", over ridden from HttpServlet
#override
protected void process(HttpServletRequest request, HttpServletResponse response) {
InputStream in = null;
OutputStream out = null;
String inXml = null;
//some more code..
}
It is reading whatever is coming into the servlet.
How can I rewrite this as rest controller in spring??

Just code it as:
#RestController
public ReturnType process(HttpServletRequest request, HttpServletResponse response {
//...
}
and check this part of the Spring MVC documentation as well:
#RequestMapping handler methods have a flexible signature and can choose from a range of supported controller method arguments and return values.
Note, that:
whatever you return from your Rest-Controller turns into HTTP Response Body;
you can define #RestController on the class level.

Spring #RequestMapping

I have a question with Spring MVC RequestMapping annotation. need your help.
I have created one IPSLcontroller and i want that IPSLcontroller to handle all request url.i have created two method in this controller.
1)handleLogoutRequest :- this method should invoke on below url.
2)handleRequest :- this method should invoke on all request url otherthan logout.
http://localhost:9086/webapp/login
or
http://localhost:9086/webapp/add
or
http://localhost:9086/webapp/remove
here is my sample code. but it's not working as expected.
#Controller
public class IPSLController {
#RequestMapping(value={"/logout/*"},method = RequestMethod.POST)
protected void handleLogoutRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController logout request.......................................");
}
#RequestMapping(method = RequestMethod.POST,value={"/*"})
protected void handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController all request Post.......................................");
}
}

You should use a general Prefix for every controller you use, so you can differ between them better. Also you don´t need any "/" for calls like this.
#Controller
#RequestMapping("ispl")
public class IPSLController {
#RequestMapping(value={"logout"},method = RequestMethod.POST)
protected void handleLogoutRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController logout request.......................................");
}
#RequestMapping(method = RequestMethod.POST,value={"hello"})
protected void handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController all request Post.......................................");
}
}
If you now want to call them over a ServletRequest or with a restService or something similar you should declare them like this
#GET
#Path("ispl/logout")
public void Method (HttpServletResponse ...)

Well it is working the way it should. You have a mapping for /* and for /logout/*. So when you post to /logout it invokes the method for /*. I suspect that if you post to /logout/something it would invoke your logout handler.
If you want it to work, you cannot have a wildcard mapping for the second method. At least use /something/* so that spring can make a correct decision on mappings.

Spring 3 HandlerInterceptor passing information to Controller

I've setup a Spring HandlerInterceptor to add an attribute to the HttpServletRequest to be able to read it from the Controller, sadly this does not seem to work which seems strange to me. Am I doing things wrong? Any idea how to transmit the data from the Interceptor to the Controller?
Here is the simplified code of the two impacted classes
public class RequestInterceptor implements HandlerInterceptor {
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
request.setAttribute("my-role", "superman");
}
[...]
}
#RestController
#RequestMapping("Test")
public class TestController {
public final Logger logger = LoggerFactory.getLogger(getClass());
#RequestMapping(value = "something")
public void something(HttpServletRequest request) {
logger.info(request.getAttribute("my-role"));
}
[...]
}
The request.getAttribute("my-role") returns null... but does return the excepted value if I read it in the postHandle of the HandlerInterceptor, I feel like I'm missing something...
EDIT : I found out that going thru the session with "request.getSession().setAttribute" works as a charm, still i do not understand why the request itself does not work in this use case.

Can you try with session instead of request like below.
public boolean preHandle(HttpServletRequest request,
HttpServletResponse response, Object handler) throws Exception {
...
HttpSession session = request.getSession();
session.setAttribute("attributeName", objectYouWantToPassToHandler);
....
}
In your handler handleRequest method:
public ModelAndView handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
....
HttpSession session = request.getSession();
objectYouWantToPassToHandler objectYouWantToPassToHandler = session.getAttribute("attributeName");
....
}

how to mock a servletContext instead of Servlet or HttpServletRequest?

I have an independent project for writing test cases; the problem is I can't mock HttpServletRequest, simply because in my servlet there are calls like getServletContext() as test cases are running from the outside servlet container. It will always return an error saying "no context found". This is just one dependency with the servlet container; there can be hundreds. For example, initialContext.lookup() also depends on a container.
How can I use Mockito to write a test case in this scenario? Please don't ask for an error message; it's more of a logical problem than technical.
Looking on the internet for tutorials makes me wonder if I am doing something seriously wrong. No one seems to have encountered this problem before... How can you mock HttpServletRequest without ever having getServletContext() called in the servlet? I mean seriously, how rare can it be?

You have a servlet implementation that uses the ServletContext, e.g.
public class SomeServlet extends HttpServlet{
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
ServletContext servletContext = getServletContext();
Object attribute = servletContext.getAttribute("test");
System.out.println(attribute.toString());
}
}
in this case you have 2 options to test the doGet method
Use powermock's partitial mocking to only mock the getServletContext method.
#RunWith(PowerMockRunner.class)
public class SomeServletTest {
#Test
public void onGet() throws ServletException, IOException{
SomeServlet someServlet = PowerMock.createPartialMock(SomeServlet.class, "getServletContext");
ServletContext servletContext = PowerMock.createNiceMock(ServletContext.class);
HttpServletRequest httpServletRequest = PowerMock.createNiceMock(HttpServletRequest.class);
HttpServletResponse httpServletResponse = PowerMock.createNiceMock(HttpServletResponse.class);
someServlet.getServletContext();
PowerMock.expectLastCall().andReturn(servletContext);
servletContext.getAttribute("test");
PowerMock.expectLastCall().andReturn("hello");
PowerMock.replay(someServlet, servletContext, httpServletRequest, httpServletResponse);
someServlet.doGet(httpServletRequest, httpServletResponse);
}
}
or a simpler way is to just override the getServletContext method. In this case you don't need powermock. You can just do it using easymock. e.g.
public class SomeServletTest {
#Test
public void onGet() throws ServletException, IOException{
HttpServletRequest httpServletRequest = EasyMock.createNiceMock(HttpServletRequest.class);
HttpServletResponse httpServletResponse = EasyMock.createNiceMock(HttpServletResponse.class);
final ServletContext servletContext = EasyMock.createNiceMock(ServletContext.class);
SomeServlet someServlet = new SomeServlet(){
public ServletContext getServletContext() {
return servletContext; // return the mock
}
};
EasyMock.expect(servletContext.getAttribute("test")).andReturn("hello");
EasyMock.replay(servletContext, httpServletRequest, httpServletResponse);
someServlet.doGet(httpServletRequest, httpServletResponse);
}
}
there can be 100's. like initialContext.lookup() also dependent on container.
In this case you can either create an InitialContext mock and use this.
If your code creates a new InitialContext, e.g.
public void someMethod(){
InitialContext context = new InitialContext();
context.lookup(....);
}
you can simply extract the InitialContext instantiation to a protected method that you can override in your tests like I showed above with the ServletContext
public void someMethod(){
InitialContext context = createInitialContext();
context.lookup(....);
}
protected InitialContext createInitialContext(){
return new InitialContext(); // can be overridden by a subclass
// and therefore by tests as well to
// return a mock
}
If you don't want or you can't modify the code in this way, then you can use Powermock to intercept the constructor.
EDIT
Can you post your Mockito code? It would be a pleasure, since the methods are named differently.
#Test
public void onGet() throws ServletException, IOException {
HttpServletRequest httpServletRequest = Mockito.mock(HttpServletRequest.class);
HttpServletResponse httpServletResponse = Mockito.mock(HttpServletResponse.class);
final ServletContext servletContext = Mockito.mock(ServletContext.class);
SomeServlet someServlet = new SomeServlet(){
public ServletContext getServletContext() {
return servletContext; // return the mock
}
};
Mockito.doReturn("hello").when(servletContext).getAttribute("test");
someServlet.doGet(httpServletRequest, httpServletResponse);
}

Static or nonstatic action in mvc?

i want to ask you about mvc. How it works. So, this is simple example(I don't use any frameworks)
in Controller(Servlet):
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
private void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String page = null;
AbstractCommand action;
action = ActionFactory.getAction(request);// get command from factory
page = action.execute(request, response);
RequestDispatcher dispatcher = getServletContext()
.getRequestDispatcher(page);
dispatcher.forward(request, response);
}
for action we create a common interface(Strategy pattern):
public interface AbstractAction {
public String execute(HttpServletRequest request, HttpServletResponse response);
}
Simple Action(Example):
public class HelloAction implements AbstractAction {
#Override
public String execute(HttpServletRequest request,
HttpServletResponse response) {
//....(some actions to modify request)
String page = "/main.jsp";
return page;
}
}
And now, our factory:
public class ActionFactory {
private enum Actions{
HELLO;
}
public static AbstractAction getAction(HttpServletRequest request){
String action = request.getParameter("action");//take parameter from jsp
Actions actionEnum = Actions.valueOf(action.toUpperCase());
switch (actionEnum) {
case HELLO:
return new HelloAction();
}
}
}
We came to the place where I am in confused. Servlet is initialized only once, and only one for all requests. Just forwards requests to the actions where we modify request or response. But, we create NEW instance of the class for every request. Here can occur memory overflow!? Or not?
Can we make these actions static(static method, one for all request)? If two requests come at the same time what will happen to them?
What do you think about this, please share your experience.
P.S. sorry for bad english.

How about Singleton pattern to get the instance of the Action class ?
Just add some abstact getInstance() method in AbstractAction.
Make every implementation provide its own instance.
In every implementation class, use Singleton pattern so that only one instance exists.
Make sure no action class stores any data related to a specific request.

As i understood the jsp, the whole thing is stateless, if u access the servlet by http request, the servlet will be created in a new instance.
After leaving the servlet by .forward(), it will be released by garbage collection.
2,3,...,n requests = 2,3,...,n servlets.
by forwarding to a jsp, the only way to access the servlet from jsp is a new http request = new servlet. ( will move to the doPost method)