How can I get access to the HttpServletRequest object when using Java Web Services

Question

I'm using Java 6, Tomcat 6, and Metro. I use WebService and WebMethod annotations to expose my web service. I would like to obtain information about the request. I tried the following code, but wsCtxt is always null. What step must I take to not get null for the WebServiceContext.

In other words: how can I execute the following line to get a non-null value for wsCtxt?

MessageContext msgCtxt = wsCtxt.getMessageContext();

@WebService
public class MyService{

  @Resource
  WebServiceContext wsCtxt;

  @WebMethod
  public void myWebMethod(){
    MessageContext msgCtxt = wsCtxt.getMessageContext();
    HttpServletRequest req = (HttpServletRequest)msgCtxt.get(MessageContext.SERVLET_REQUEST);
    String clientIP = req.getRemoteAddr();
  }

Answer 1

I recommend you either rename your variable from wsCtxt to wsContext or assign the name attribute to the @Resource annotation. The J2ee tutorial on @Resource indicates that the name of the variable is used as part of the lookup. I've encountered this same problem using resource injection in Glassfish injecting a different type of resource.

Though your correct name may not be wsContext. I'm following this java tip . If you like the variable name wsCtxt, then use the name attribute in the variable declaration:

@Resource(name="wsContext") WebServiceContext wsCtxt;

Answer 2

The following code works for me using Java 5, Tomcat 6 and Metro

Could it possibly be that there is a conflict between the WS support in Java 6 and the version of Metro you are using. Have you tried it on a Java 5 build?

@WebService
public class Sample {
    @WebMethod
    public void sample() {
        HttpSession session = findSession();
        //Stuff

    }
    private HttpSession findSession() {
        MessageContext mc = wsContext.getMessageContext();
        HttpServletRequest request = (HttpServletRequest)mc.get(MessageContext.SERVLET_REQUEST);
        return request.getSession();
    }
    @Resource
    private WebServiceContext wsContext;
}

Answer 3

I still have this problem. Here is my work-around was to write a ServletRequestListener that puts the request into a ThreadLocal var. Then the WebService can obtain the request from the ThreadLocal. In other words, I'm reimplementing something that just doesn't work for me.

Here's the Listener:

import javax.servlet.ServletRequest;
import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;

public class SDMXRequestListener implements ServletRequestListener {

    public SDMXRequestListener() {
    }

    public void requestDestroyed(ServletRequestEvent event) {
    }

    public void requestInitialized(ServletRequestEvent event) {
        final ServletRequest request = event.getServletRequest();
        ServletRequestStore.setServletRequest(request);
    }

}

Here's the ThreadLocal wrapper:

import javax.servlet.ServletRequest;

public class ServletRequestStore {

    private final static ThreadLocal<ServletRequest> servletRequests = new ThreadLocal<ServletRequest>();

    public static void setServletRequest(ServletRequest request) {
        servletRequests.set(request);
    }

    public static ServletRequest getServletRequest() {
        return servletRequests.get();
    }

}

And the web.xml wiring:

  <listener>
        <listener-class>ecb.sdw.webservices.SDMXRequestListener</listener-class>
    </listener>

The Web service uses the following code to obtain the request:

final HttpServletRequest request = (HttpServletRequest) ServletRequestStore.getServletRequest();

Answer 4

也许 javax.ws.rs.core.Context 注释是针对您要查找的内容，而不是资源？