Added means to define and implement REST web-service and its clients.

Added missing copyright headers.
Added TypedKey based methods in request/response classes.

wsclient/src/main/java/com/google/gson/webservice/client/ResponseReceiver.java

@@ -32,6 +32,7 @@ import com.google.gson.webservice.definition.ResponseBody;
 import com.google.gson.webservice.definition.ResponseBodySpec;
 import com.google.gson.webservice.definition.ResponseSpec;
 import com.google.gson.webservice.definition.WebServiceResponse;
+import com.google.gson.webservice.definition.WebServiceSystemException;
 
 /**
  * Receives a response coming on an {@link HttpURLConnection}.
@@ -63,7 +64,7 @@ public final class ResponseReceiver {
       ResponseBody responseBody = readResponseBody(conn, bodySpec);
       return new WebServiceResponse(responseParams, responseBody);
     } catch (IOException e) {
-      throw new RuntimeException(e);
+      throw new WebServiceSystemException(e);
     }
   }
 

wsclient/src/main/java/com/google/gson/webservice/client/RestClient.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2008 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.client;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.webservice.definition.WebServiceSystemException;
+import com.google.gson.webservice.definition.rest.RestCallSpec;
+import com.google.gson.webservice.definition.rest.RestRequest;
+import com.google.gson.webservice.definition.rest.RestResponse;
+
+/**
+ * Main class used by clients to access a Gson Web service.
+ * 
+ * @author inder
+ */
+public final class RestClient {
+  private final WebServiceConfig config;
+  private final Logger logger;
+  private final Level logLevel;
+
+  public RestClient(WebServiceConfig serverConfig) {
+    this(serverConfig, null);
+  }
+
+  public RestClient(WebServiceConfig serverConfig, Level logLevel) {
+    this.config = serverConfig;
+    this.logger = logLevel == null ? null : Logger.getLogger(RestClient.class.getName());
+    this.logLevel = logLevel;
+  }
+  
+  private URL getWebServiceUrl(RestCallSpec<?> callSpec) {
+    String url = config.getServiceBaseUrl() + callSpec.getPath().get();
+    try {
+      return new URL(url);
+    } catch (MalformedURLException e) {
+      throw new RuntimeException(e);
+    }
+  }
+  
+  public <R> RestResponse<R> getResponse(RestCallSpec<R> callSpec, RestRequest<R> request) {
+    Gson gson = new GsonBuilder().create();
+    return getResponse(callSpec, request, gson);
+  }
+
+  public <R> RestResponse<R> getResponse(
+      RestCallSpec<R> callSpec, RestRequest<R> request, Gson gson) {
+    try {
+      URL webServiceUrl = getWebServiceUrl(callSpec);
+      if (logger != null) {
+        logger.log(logLevel, "Opening connection to " + webServiceUrl);
+      }
+      HttpURLConnection conn = (HttpURLConnection) webServiceUrl.openConnection();
+      RestRequestSender requestSender = new RestRequestSender(gson, logLevel);
+      requestSender.send(conn, request);
+      RestResponseReceiver<R> responseReceiver =
+        new RestResponseReceiver<R>(gson, callSpec.getResponseSpec(), logLevel);
+      return responseReceiver.receive(conn);
+    } catch (IOException e) {
+      throw new WebServiceSystemException(e);
+    } catch (IllegalArgumentException e) {
+      throw new WebServiceSystemException(e);
+    }
+  }
+  
+  @Override
+  public String toString() {
+    return String.format("config:%s", config);
+  }
+}

wsclient/src/main/java/com/google/gson/webservice/client/RestRequestSender.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.client;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.net.HttpURLConnection;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.google.gson.Gson;
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.HeaderMapSpec;
+import com.google.gson.webservice.definition.WebServiceSystemException;
+import com.google.gson.webservice.definition.rest.RestRequest;
+
+/**
+ * Class to send Web service requests on a {@link HttpURLConnection}.
+ * 
+ * @author inder
+ */
+public final class RestRequestSender {
+  private final Gson gson;
+  private final Logger logger;
+  private final Level logLevel;
+
+  public RestRequestSender(Gson gson) {
+    this(gson, null);
+  }
+
+  public RestRequestSender(Gson gson, Level logLevel) {
+    this.gson = gson;
+    logger = logLevel == null ? null : Logger.getLogger(RestRequestSender.class.getName());
+    this.logLevel = logLevel;
+  }
+  
+  public <R> void send(HttpURLConnection conn, RestRequest<R> request) {    
+    try {
+      conn.setRequestMethod(request.getHttpMethod().toString());
+      setHeader(conn, "Content-Type", request.getContentType(), true);
+      
+      // Assume conservatively that the response will need to be read.
+      // This is done here instead of in the response receiver because this property must be set
+      // before sending any data on the connection.
+      conn.setDoInput(true);
+      
+      R requestBody = request.getBody();
+      String requestBodyContents = "";
+      // Android Java VM ignore Content-Length if setDoOutput is not set
+      conn.setDoOutput(true);    
+      if (requestBody != null) {
+        requestBodyContents = gson.toJson(requestBody);
+      }
+      String contentLength = String.valueOf(requestBodyContents.length());
+      setHeader(conn, "Content-Length", contentLength, true);
+      addRequestParams(conn, request.getHeaders());
+      if (requestBodyContents != null) {
+        Streams.copy(requestBodyContents, conn.getOutputStream(), false);
+      }
+      
+      // Initiate the sending of the request.
+      conn.connect();
+    } catch (IOException e) {
+      throw new WebServiceSystemException(e);
+    }
+  }
+
+  private void addRequestParams(HttpURLConnection conn, HeaderMap requestParams) {
+    HeaderMapSpec spec = requestParams.getSpec();
+    for (Map.Entry<String, Object> entry : requestParams.entrySet()) {
+      String paramName = entry.getKey();
+      Type type = spec.getTypeFor(paramName);
+      Object value = entry.getValue();
+      String json = gson.toJson(value, type);
+      setHeader(conn, paramName, json, false);
+    }
+  }
+
+  private void setHeader(HttpURLConnection conn, String name, String value, boolean overwrite) {
+    if (logger != null) {
+      logger.log(logLevel, String.format("Request param: %s:%s", name, value));
+    }
+    if (overwrite) {
+      conn.setRequestProperty(name, value);
+    } else {
+      conn.addRequestProperty(name, value);
+    }
+  }  
+}

wsclient/src/main/java/com/google/gson/webservice/client/RestResponseReceiver.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.client;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.lang.reflect.Type;
+import java.net.HttpURLConnection;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.google.gson.Gson;
+import com.google.gson.webservice.definition.ContentBodySpec;
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.HeaderMapSpec;
+import com.google.gson.webservice.definition.WebServiceSystemException;
+import com.google.gson.webservice.definition.rest.RestResponse;
+import com.google.gson.webservice.definition.rest.RestResponseSpec;
+
+/**
+ * Receives a response coming on an {@link HttpURLConnection}.
+ * 
+ * @author inder
+ */
+public final class RestResponseReceiver<R> {
+  private final Gson gson;
+  private final RestResponseSpec<R> spec;
+  private final Logger logger;
+  private final Level logLevel;
+
+  public RestResponseReceiver(Gson gson, RestResponseSpec<R> spec) {
+    this(gson, spec, null);
+  }
+  public RestResponseReceiver(Gson gson, RestResponseSpec<R> spec, Level logLevel) {
+    this.gson = gson;
+    this.spec = spec;
+    this.logger = logLevel == null ? null : Logger.getLogger(RestResponseReceiver.class.getName());
+    this.logLevel = logLevel;
+  }
+  
+  public RestResponse<R> receive(HttpURLConnection conn) {
+    try {
+      HeaderMapSpec paramSpec = spec.getHeadersSpec();
+      Class<R> bodySpec = spec.getResourceClass();
+      // read response
+      HeaderMap responseParams = readResponseHeaders(conn, paramSpec);
+      R responseBody = readResponseBody(conn, bodySpec);
+      return new RestResponse<R>(responseParams, responseBody);
+    } catch (IOException e) {
+      throw new WebServiceSystemException(e);
+    }
+  }
+
+  private HeaderMap readResponseHeaders(HttpURLConnection conn, HeaderMapSpec paramsSpec) {    
+    HeaderMap.Builder paramsBuilder = new HeaderMap.Builder(paramsSpec);    
+    for (Map.Entry<String, Type> entry : paramsSpec.entrySet()) {
+      String paramName = entry.getKey();
+      String json = conn.getHeaderField(paramName);
+      if (json != null) {
+        if (logger != null) {
+          logger.log(logLevel, String.format("Response Header: %s:%s\n", paramName, json));
+        }
+        Type typeOfT = paramsSpec.getTypeFor(paramName);
+        Object value = gson.fromJson(json, typeOfT);
+        paramsBuilder.put(paramName, value, typeOfT);
+      }
+    }
+    return paramsBuilder.build();
+  }
+
+  private R readResponseBody(HttpURLConnection conn, Class<R> resourceClass) throws IOException {
+    String connContentType = conn.getContentType();
+    Preconditions.checkArgument(connContentType.contains(ContentBodySpec.JSON_CONTENT_TYPE), conn);
+    Reader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
+    R body = gson.fromJson(reader, resourceClass);
+    return body;
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/ContentBodySpec.java

@@ -25,10 +25,10 @@ import java.util.Set;
  * 
  * @author inder
  */
-class ContentBodySpec implements ParamMapSpec {
+public class ContentBodySpec implements ParamMapSpec {
 
   public static final String JSON_CONTENT_TYPE = "application/json";
-  private static final String JSON_CHARACTER_ENCODING = "utf-8";
+  public static final String JSON_CHARACTER_ENCODING = "utf-8";
   
   private final Map<String, Type> paramsSpec;
 

wsdef/src/main/java/com/google/gson/webservice/definition/HttpMethod.java

@@ -15,6 +15,10 @@
  */
 package com.google.gson.webservice.definition;
 
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
 /**
  * An enum of Http methods to provide strongly-typed versions instead of strings. 
  * 
@@ -29,4 +33,7 @@ public enum HttpMethod {
   public static HttpMethod getMethod(String method) {
     return valueOf(method.trim().toUpperCase());
   }
+  
+  public static final List<HttpMethod> ALL_METHODS =
+    Collections.unmodifiableList(Arrays.asList(values()));
 }

wsdef/src/main/java/com/google/gson/webservice/definition/TypedKey.java

@@ -1,5 +1,27 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.google.gson.webservice.definition;
 
+/**
+ * A typed key for use in a {@link ParamMap} or a {@link ParamMapSpec}.
+ *
+ * @author inder
+ *
+ * @param <T> Intended type of the content for the key
+ */
 public class TypedKey<T> {
   private final String name;
   private final Class<T> classOfT;

wsdef/src/main/java/com/google/gson/webservice/definition/WebServiceResponse.java

@@ -50,6 +50,10 @@ public final class WebServiceResponse {
       return this;
     }
     
+    public <T> Builder putBody(TypedKey<T> paramName, T content) {
+      return putBody(paramName.getName(), content);
+    }
+
     public Builder putBody(String paramName, Object content) {
       body.put(paramName, content);
       return this;

wsdef/src/main/java/com/google/gson/webservice/definition/rest/Preconditions.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+final class Preconditions {
+
+  public static void checkArgument(boolean condition) {
+    if (!condition) {
+      throw new IllegalArgumentException();
+    }
+  }
+
+  public static void checkNotNull(Object obj) {
+    if (obj == null) {
+      throw new IllegalArgumentException();
+    }
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/ResourceMap.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.google.gson.webservice.definition.CallPath;
+
+/**
+ * A {@link Map} of {@link CallPath} to {@link RestCallSpec}
+ *
+ * @author inder
+ */
+public final class ResourceMap {
+
+  public static final class Builder {
+    private final Map<CallPath, RestCallSpec<?>> resources =
+      new HashMap<CallPath, RestCallSpec<?>>();
+    
+    public <R> Builder set(CallPath callPath, RestCallSpec<R> spec) {
+      resources.put(callPath, spec);
+      return this;
+    }
+
+    public ResourceMap build() {
+      return new ResourceMap(resources);
+    }
+  }
+
+  private final Map<CallPath, RestCallSpec<?>> resources;
+
+  public ResourceMap(Map<CallPath, RestCallSpec<?>> resources) {
+    this.resources = resources;
+  }
+
+  public <T> RestCallSpec<T> get(CallPath callPath) {
+    @SuppressWarnings("unchecked")
+    RestCallSpec<T> restCallSpec = (RestCallSpec<T>)resources.get(callPath);
+    return restCallSpec;
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestCall.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+/**
+ * The data associated with a Rest Web service call. This includes http request header parameters
+ * (form and URL parameters), request body, response header parameters, and resource response body. 
+ * 
+ * @author inder
+ */
+public final class RestCall<R> {
+  
+  private final RestCallSpec<R> callSpec;
+  private final RestRequest<R> request;
+  private final RestResponse<R> response;
+  
+  public RestCall(RestCallSpec<R> callSpec, RestRequest<R> request, RestResponse<R> response) {
+    this.callSpec = callSpec;
+    this.request = request;
+    this.response = response;
+  }
+
+  public RestCallSpec<R> getSpec() {
+    return callSpec;
+  }
+  
+  public RestRequest<R> getRequest() {
+    return request;
+  }
+
+  public RestResponse<R> getResponse() {
+    return response;
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestCallSpec.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import com.google.gson.webservice.definition.CallPath;
+import com.google.gson.webservice.definition.HeaderMapSpec;
+import com.google.gson.webservice.definition.HttpMethod;
+import com.google.gson.webservice.definition.TypedKey;
+
+/**
+ * Specification for a REST service
+ *
+ * @author inder
+ */
+public final class RestCallSpec<R> {
+  public static class Builder<R> {
+    private final CallPath callPath;
+    private final Set<HttpMethod> supportedHttpMethods = new LinkedHashSet<HttpMethod>();
+    private final HeaderMapSpec.Builder reqParamsSpecBuilder = new HeaderMapSpec.Builder();
+    private final HeaderMapSpec.Builder resParamsSpecBuilder = new HeaderMapSpec.Builder();
+    private final Class<R> resourceClass;
+    
+    public Builder(CallPath callPath, Class<R> resourceClass) {
+      this.callPath = callPath;
+      supportedHttpMethods.addAll(HttpMethod.ALL_METHODS);
+      this.resourceClass = resourceClass;
+    }
+
+    public Builder<R> disableHttpMethod(HttpMethod httpMethod) {
+      supportedHttpMethods.remove(httpMethod);
+      return this;
+    }
+    
+    public <T> Builder<R> addRequestParam(TypedKey<T> paramKey, Class<T> typeOfParam) {
+      reqParamsSpecBuilder.put(paramKey.getName(), typeOfParam);
+      return this;
+    }
+
+    public <T> Builder<R> addResponseParam(TypedKey<T> paramKey, Class<T> typeOfParam) {
+      resParamsSpecBuilder.put(paramKey.getName(), typeOfParam);
+      return this;
+    }
+
+    public RestCallSpec<R> build() {
+      if (supportedHttpMethods.isEmpty()) {
+        supportedHttpMethods.addAll(Arrays.asList(HttpMethod.values()));
+      }
+      RestRequestSpec<R> requestSpec = 
+        new RestRequestSpec<R>(reqParamsSpecBuilder.build(), resourceClass);
+      RestResponseSpec<R> responseSpec =
+        new RestResponseSpec<R>(resParamsSpecBuilder.build(), resourceClass);
+      return new RestCallSpec<R>(supportedHttpMethods, callPath, 
+          requestSpec, responseSpec);
+    }
+  }
+
+  private final Set<HttpMethod> supportedHttpMethods;
+  private final CallPath path;
+  private final RestRequestSpec<R> requestSpec;
+  private final RestResponseSpec<R> responseSpec;
+
+  private RestCallSpec(Set<HttpMethod> supportedHttpMethods, CallPath path,
+      RestRequestSpec<R> requestSpec, RestResponseSpec<R> responseSpec) {
+    Preconditions.checkArgument(!supportedHttpMethods.isEmpty());
+    Preconditions.checkNotNull(path);
+    this.supportedHttpMethods = supportedHttpMethods;
+    this.path = path;
+    this.requestSpec = requestSpec;
+    this.responseSpec = responseSpec;
+  }
+
+  public CallPath getPath() {
+    return path;
+  }
+  
+  public Set<HttpMethod> getSupportedHttpMethods() {
+    return supportedHttpMethods;
+  }
+
+  public RestResponseSpec<R> getResponseSpec() {
+    return responseSpec;
+  }
+  
+  public RestRequestSpec<R> getRequestSpec() {
+    return requestSpec;
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestRequest.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import com.google.gson.webservice.definition.ContentBodySpec;
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.HttpMethod;
+import com.google.gson.webservice.definition.RequestBody;
+
+/**
+ * The data associated with a Web service request. This includes HTTP request header parameters 
+ * (form and URL parameters), and {@link RequestBody}. 
+ * 
+ * @author inder
+ */
+public final class RestRequest<R> {
+  private final HttpMethod method;
+  private final HeaderMap headers;
+  private final R body;
+  private final RestRequestSpec<R> spec;
+  
+  public RestRequest(HttpMethod method, HeaderMap requestHeaders,
+      R requestBody, Class<R> resourceClass) {
+    this.method = method;
+    this.body = requestBody;
+    this.headers = requestHeaders;
+    this.spec = new RestRequestSpec<R>(requestHeaders.getSpec(), resourceClass);
+  }
+
+  public HttpMethod getMethod() {
+    return method;
+  }
+
+  public RestRequestSpec<R> getSpec() {
+    return spec;
+  }
+
+  public HttpMethod getHttpMethod() {
+    return method;
+  }
+
+  public R getBody() {
+    return body;
+  }
+
+  public HeaderMap getHeaders() {
+    return headers;
+  }
+
+  public String getContentType() {
+    return ContentBodySpec.JSON_CONTENT_TYPE;
+  }
+  
+  @SuppressWarnings("unchecked")
+  public <T> T getHeader(String headerName) {
+    return (T) headers.get(headerName);
+  }
+  
+  @Override
+  public String toString() {
+    return String.format("{method:%s,headers:%s,body:%s}", method, headers, body);
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestRequestSpec.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import com.google.gson.webservice.definition.HeaderMapSpec;
+
+/**
+ * Specification for a {@link RestRequest}.
+ * 
+ * @author inder
+ */
+public final class RestRequestSpec<R> {
+  private final HeaderMapSpec headersSpec;
+  private final Class<R> resourceClass;
+
+  public RestRequestSpec(HeaderMapSpec headersSpec, Class<R> resourceClass) {
+    this.headersSpec = headersSpec;
+    this.resourceClass = resourceClass;
+  }
+
+  public Class<R> getResourceClass() {
+    return resourceClass;
+  }
+
+  public HeaderMapSpec getHeadersSpec() {
+    return headersSpec;
+  }
+  
+  @Override
+  public String toString() {
+    return String.format("{headersSpec:%s,resourceClass:%s}", headersSpec, resourceClass);
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestResponse.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.TypedKey;
+
+/**
+ * The data associated with a REST Web service response. This includes http response header
+ * parameters, and the response body. 
+ * 
+ * @author inder
+ */
+public final class RestResponse<R> {
+  
+  private final HeaderMap headers;
+  private final R body;
+  private final RestResponseSpec<R> spec;
+  
+  public static class Builder<R> {
+    private final HeaderMap.Builder headers;
+    private R body;
+    private final RestResponseSpec<R> spec;
+    
+    public Builder(RestResponseSpec<R> spec) {
+      this.spec = spec;
+      headers = new HeaderMap.Builder(spec.getHeadersSpec());
+    }
+    
+    public <T> Builder<R> putHeader(TypedKey<T> paramName, T content) {
+      headers.put(paramName.getName(), content, paramName.getClassOfT());
+      return this;
+    }
+    
+    public Builder<R> setBody(R body) {
+      this.body = body;
+      return this;
+    }
+
+    public RestResponse<R> build() {
+      return new RestResponse<R>(spec, headers.build(), body);
+    }
+  }
+  
+  private RestResponse(RestResponseSpec<R> spec, HeaderMap headers, R body) {
+    this.spec = spec;
+    this.headers = headers;
+    this.body = body;
+  }
+  
+  @SuppressWarnings("unchecked")
+  public RestResponse(HeaderMap responseHeaders, R responseBody) {
+    this.spec = new RestResponseSpec<R>(responseHeaders.getSpec(),
+        (Class<R>)responseBody.getClass());
+    this.headers = responseHeaders;
+    this.body = responseBody;
+  }
+
+  public RestResponseSpec<R> getSpec() {
+    return spec;
+  }
+
+  public HeaderMap getHeaders() {
+    return headers;
+  }
+  
+  public R getBody() {
+    return body;
+  }
+
+  @SuppressWarnings("unchecked")
+  public <T> T getHeader(String headerName) {
+    return (T) headers.get(headerName);
+  }
+  
+  @Override
+  public String toString() {
+    return String.format("{headers:%s, body:%s}", headers, body);
+  }
+}

wsdef/src/main/java/com/google/gson/webservice/definition/rest/RestResponseSpec.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.webservice.definition.rest;
+
+import com.google.gson.webservice.definition.HeaderMapSpec;
+
+/**
+ * Specification for a {@link RestResponse}.
+ * 
+ * @author inder
+ */
+public final class RestResponseSpec<R> {
+  private final HeaderMapSpec headersSpec;
+  private final Class<R> resourceClass;
+
+  public RestResponseSpec(HeaderMapSpec headersSpec, Class<R> resourceClass) {
+    this.headersSpec = headersSpec;
+    this.resourceClass = resourceClass;
+  }
+
+  public Class<R> getResourceClass() {
+    return resourceClass;
+  }
+
+  public HeaderMapSpec getHeadersSpec() {
+    return headersSpec;
+  }
+  
+  @Override
+  public String toString() {
+    return String.format("{headersSpec:%s,resourceClass:%s}", headersSpec, resourceClass);
+  }
+}

wsf/src/main/java/com/google/gson/wsf/server/ResponseSender.java

@@ -26,7 +26,6 @@ import com.google.gson.Gson;
 import com.google.gson.webservice.definition.HeaderMap;
 import com.google.gson.webservice.definition.HeaderMapSpec;
 import com.google.gson.webservice.definition.ResponseBody;
-import com.google.gson.webservice.definition.ResponseBodySpec;
 import com.google.gson.webservice.definition.WebServiceResponse;
 
 /**
@@ -45,7 +44,6 @@ public final class ResponseSender {
   
   public void send(HttpServletResponse conn, WebServiceResponse response) {
     try {
-      conn.setContentType(ResponseBodySpec.JSON_CONTENT_TYPE);
       sendHeaders(conn, response.getHeaders());
       sendBody(conn, response.getBody());
     } catch (IOException e) {

wsf/src/main/java/com/google/gson/wsf/server/rest/RestRequestReceiver.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2008 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.wsf.server.rest;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.lang.reflect.Type;
+import java.util.Map;
+
+import javax.servlet.http.HttpServletRequest;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonParseException;
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.HeaderMapSpec;
+import com.google.gson.webservice.definition.HttpMethod;
+import com.google.gson.webservice.definition.WebServiceSystemException;
+import com.google.gson.webservice.definition.rest.RestRequest;
+import com.google.gson.webservice.definition.rest.RestRequestSpec;
+
+/**
+ * Receives and parses a request at the server side on a {@link HttpServletRequest}.  
+ * 
+ * @author inder
+ */
+public final class RestRequestReceiver<R> {
+
+  private final Gson gson;
+  private final RestRequestSpec<R> spec;
+
+  public RestRequestReceiver(Gson gson, RestRequestSpec<R> spec) {
+    this.gson = gson;
+    this.spec = spec;
+  }
+  
+  public RestRequest<R> receive(HttpServletRequest request) {
+    try {
+      HeaderMap requestParams = buildRequestParams(request);
+      R requestBody = buildRequestBody(request);
+      
+      HttpMethod method = HttpMethod.getMethod(request.getMethod());
+      return new RestRequest<R>(method, requestParams, requestBody, spec.getResourceClass());
+    } catch (IOException e) {
+      throw new WebServiceSystemException(e);
+    } catch (JsonParseException e) {
+      // Not a Web service request
+      throw new WebServiceSystemException(e);
+    }
+  }
+  
+  private HeaderMap buildRequestParams(HttpServletRequest request) {
+    HeaderMapSpec paramsSpec = this.spec.getHeadersSpec();
+    HeaderMap.Builder paramsBuilder = new HeaderMap.Builder(paramsSpec);
+    for (Map.Entry<String, Type> param : paramsSpec.entrySet()) {
+      String name = param.getKey();
+      Type type = param.getValue();
+      String header = request.getHeader(name);
+      if (header == null || header.equals("")) {
+        // check parameter map for the value
+        header = request.getParameter(name);
+      }
+      if (header != null && !header.equals("")) { 
+        Object value = gson.fromJson(header, type);
+        paramsBuilder.put(name, value);
+      }
+    }
+    return paramsBuilder.build();
+  }
+  
+  private R buildRequestBody(HttpServletRequest request) throws IOException {
+    Class<R> resourceClass = spec.getResourceClass();
+    Reader reader = new BufferedReader(new InputStreamReader(request.getInputStream()));
+    R requestBody = gson.fromJson(reader, resourceClass);
+    return requestBody;
+  }
+}

wsf/src/main/java/com/google/gson/wsf/server/rest/RestResponseBuilder.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.wsf.server.rest;
+
+import com.google.gson.webservice.definition.rest.RestRequest;
+import com.google.gson.webservice.definition.rest.RestResponse;
+import com.google.gson.webservice.definition.rest.RestCallSpec;
+
+public interface RestResponseBuilder<R> {
+  public void buildResponse(RestCallSpec<R> callSpec, RestRequest<R> request,
+      RestResponse.Builder<R> responseBuilder); 
+}

wsf/src/main/java/com/google/gson/wsf/server/rest/RestResponseSender.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2008 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.gson.wsf.server.rest;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.Map;
+import java.util.logging.Logger;
+
+import javax.servlet.http.HttpServletResponse;
+
+import com.google.gson.Gson;
+import com.google.gson.webservice.definition.ContentBodySpec;
+import com.google.gson.webservice.definition.HeaderMap;
+import com.google.gson.webservice.definition.HeaderMapSpec;
+import com.google.gson.webservice.definition.rest.RestResponse;
+
+/**
+ * Sends a JSON web service response on {@link HttpServletResponse}.
+ * 
+ * @author inder
+ */
+public final class RestResponseSender<R> {
+  private static final Logger logger = Logger.getLogger(RestResponseSender.class.getCanonicalName());
+
+  private Gson gson;
+
+  public RestResponseSender(Gson gson) {
+    this.gson = gson;
+  }
+  
+  public void send(HttpServletResponse conn, RestResponse<R> response) {
+    try {
+      sendHeaders(conn, response.getHeaders());
+      sendBody(conn, response.getBody());
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+ 
+  private void sendHeaders(HttpServletResponse conn, HeaderMap responseParams) {
+    HeaderMapSpec spec = responseParams.getSpec();
+    for (Map.Entry<String, Object> param : responseParams.entrySet()) {
+      String paramName = param.getKey();
+      Object paramValue = param.getValue();
+      Type paramType = spec.getTypeFor(paramName);
+      String json = gson.toJson(paramValue, paramType);
+      logger.fine("RESPONSE HEADER:{" + paramName + ", " + json + "}");
+      conn.addHeader(paramName, json);
+    }
+  }
+
+  private void sendBody(HttpServletResponse conn, R responseBody) throws IOException {
+    conn.setContentType(ContentBodySpec.JSON_CONTENT_TYPE);
+    conn.setCharacterEncoding(ContentBodySpec.JSON_CHARACTER_ENCODING);
+    String json = gson.toJson(responseBody);
+    logger.fine("RESPONSE BODY:" + json);
+    conn.getWriter().append(json);
+  }
+}