其实一直对gwt servlet 如何与 spring frame work结合有点疑惑,今天瞄了两眼RemoteServiceServlet 的代码, 大概有点思路了,GWT RPC service client端提交数据,应该用的仍然是post方法,所以servlet处理客户端的Request调用的是doPost方法
RemoteServiceServlet 的基类 AbstractRemoteServiceServlet 里定义了doPost 方法如下:
@Override public final void doPost(HttpServletRequest request, HttpServletResponse response) { ...... processPost(request, response); ...... }
省略了一些check,try,catch,就剩 processPost 方法了. 该方法定义在 RemoteServiceServlet 中
@Override public final void processPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException, SerializationException { // Read the request fully. // String requestPayload = readContent(request); // Let subclasses see the serialized request. // onBeforeRequestDeserialized(requestPayload); // Invoke the core dispatching logic, which returns the serialized // result. // String responsePayload = processCall(requestPayload); // Let subclasses see the serialized response. // onAfterResponseSerialized(responsePayload); // Write the response. // writeResponse(request, response, responsePayload); }
接着是这里调用的processCall方法
public String processCall(String payload) throws SerializationException { // First, check for possible XSRF situation checkPermutationStrongName(); try { RPCRequest rpcRequest = RPC.decodeRequest(payload, delegate.getClass(), this); onAfterRequestDeserialized(rpcRequest); return RPC.invokeAndEncodeResponse(delegate, rpcRequest.getMethod(), rpcRequest.getParameters(), rpcRequest.getSerializationPolicy(), rpcRequest.getFlags()); } catch (IncompatibleRemoteServiceException ex) { log( "An IncompatibleRemoteServiceException was thrown while processing this call.", ex); return RPC.encodeResponseForFailure(null, ex); } catch (RpcTokenException tokenException) { log("An RpcTokenException was thrown while processing this call.", tokenException); return RPC.encodeResponseForFailure(null, tokenException); } }
看到这里已经大致有点想法了,其实 RPC.invokeAndEncodeResponse 的调用已经完成了 调用server端方法,将结果组织成为String(serizable, 不知道这个词用的对不对,用错了见笑,请指正哈)的过程 ,该方法的第一个参数就是包含要调用的server端的方法(第二个参数)的实例,因此我们若想将spring框架和 GWT的 Servlet 结合起来 其实是要将第一个参数替换为通过spring的 beanfactory得到的各种bean实例.