GWT and Spring Framework 3.0 integration

DateService.java

import java.util.Date;

public interface DateService {
   Date getCurrentTime();
}

DateServiceImpl.java

import java.util.Date;

@Controller
@RequestMapping( value = "/date" )
public class DateServiceImpl extends GwtSpringController implements DateService {

    @Override
    public Date getCurrentTime() {
        return new Date();
    }
}

GwtSpringController.java

import com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.server.rpc.RPC;
import com.google.gwt.user.server.rpc.RPCRequest;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Enumeration;
import java.util.Properties;

public abstract class GwtSpringController extends RemoteServiceServlet implements InitializingBean, DisposableBean {
    private String servletName;

    private Properties initParameters = new Properties();

    @Autowired
    private ServletContext servletContext;

    protected GwtSpringController() {
    }

    protected GwtSpringController( String servletName ) {
        this( servletName, new Properties() );
    }

    protected GwtSpringController( String servletName, 
            Properties initParameters ) {
        Assert.notNull( initParameters, "'initParameters' should be specified" );

        this.servletName = servletName;
        this.initParameters = initParameters;
    }

    @RequestMapping( method = {
            RequestMethod.POST, RequestMethod.GET, RequestMethod.PUT, 
            RequestMethod.DELETE, RequestMethod.HEAD, 
            RequestMethod.OPTIONS, RequestMethod.TRACE
    } )
    public void handleRequest( HttpServletRequest httpServletRequest, 
HttpServletResponse httpServletResponse ) throws Exception {
        service( httpServletRequest, httpServletResponse );
    }

    public String processCall( String payload ) throws SerializationException {
        try {
            RPCRequest rpcRequest = RPC.decodeRequest( payload, getClass() );

            // delegate work to the spring injected service
            return RPC.invokeAndEncodeResponse( this, rpcRequest.getMethod(),
rpcRequest.getParameters() );
        } catch ( IncompatibleRemoteServiceException e ) {
            return RPC.encodeResponseForFailure( null, e );
        }
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        init( new ServletConfigStub() );
    }

    private class ServletConfigStub implements ServletConfig {
        public String getServletName() {
            return servletName;
        }

        public ServletContext getServletContext() {
            return servletContext;
        }

        public String getInitParameter( String paramName ) {
            return initParameters.getProperty( paramName );
        }

        public Enumeration getInitParameterNames() {
            return initParameters.keys();
        }
    }
}