Java Web Services: Up and Running, 2nd Edition

The Transport Level

So far this chapter has focused on the distinction, within JAX-WS, between the application and handler levels. JAX-WS also provides access, on either the client side or the service side, to the transport level, which is usually HTTP(S). Such access has been used but not studied in earlier examples. This section focuses on the transport level with the deliberately minimalist Echo service and a sample EchoClient. Access to the transport level will be especially useful in the next chapter on security.

The Echo service (see Example 5-13) relies upon dependency injection through the @Resource annotation to get a non-null reference to the WebServiceContext (line 1). The WebServiceContext, in turn, can be used to access the MessageContext (line 2), which provides information about the transport level. To illustrate such access, the echo method gets the HTTP request headers as a Map (line 3) and then prints the map’s contents to the standard output (line 4).

Example 5-13. The Echo service, which accesses the transport level

package mctx;

import java.util.Map;
import java.util.Set;
import javax.annotation.Resource;
import javax.jws.WebService;
import javax.jws.WebMethod;
import javax.xml.ws.WebServiceContext;
import javax.xml.ws.handler.MessageContext;


@WebService
public class Echo {
    @Resource
    WebServiceContext wctx;                                                       
    @WebMethod
    public String echo(String in) {
        String out