| // Copyright (C) 2012 The Android Open Source Project |
| // |
| // 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.gerrit.client.rpc; |
| |
| import static com.google.gwt.http.client.RequestBuilder.DELETE; |
| import static com.google.gwt.http.client.RequestBuilder.GET; |
| import static com.google.gwt.http.client.RequestBuilder.POST; |
| import static com.google.gwt.http.client.RequestBuilder.PUT; |
| |
| import com.google.gerrit.client.Gerrit; |
| import com.google.gerrit.client.RpcStatus; |
| import com.google.gwt.core.client.GWT; |
| import com.google.gwt.core.client.JavaScriptObject; |
| import com.google.gwt.http.client.Request; |
| import com.google.gwt.http.client.RequestBuilder; |
| import com.google.gwt.http.client.RequestBuilder.Method; |
| import com.google.gwt.http.client.RequestCallback; |
| import com.google.gwt.http.client.RequestException; |
| import com.google.gwt.http.client.Response; |
| import com.google.gwt.http.client.URL; |
| import com.google.gwt.json.client.JSONException; |
| import com.google.gwt.json.client.JSONObject; |
| import com.google.gwt.json.client.JSONParser; |
| import com.google.gwt.json.client.JSONValue; |
| import com.google.gwt.user.client.rpc.AsyncCallback; |
| import com.google.gwt.user.client.rpc.StatusCodeException; |
| |
| /** Makes a REST API call to the server. */ |
| public class RestApi { |
| private static final int SC_UNAVAILABLE = 2; |
| private static final int SC_BAD_TRANSPORT = 3; |
| private static final int SC_BAD_RESPONSE = 4; |
| private static final String JSON_TYPE = "application/json"; |
| private static final String JSON_UTF8 = JSON_TYPE + "; charset=utf-8"; |
| private static final String TEXT_TYPE = "text/plain"; |
| |
| /** |
| * Expected JSON content body prefix that prevents XSSI. |
| * <p> |
| * The server always includes this line as the first line of the response |
| * content body when the response body is formatted as JSON. It gets inserted |
| * by the server to prevent the resource from being imported into another |
| * domain's page using a <script> tag. This line must be removed before |
| * the JSON can be parsed. |
| */ |
| private static final String JSON_MAGIC = ")]}'\n"; |
| |
| /** True if err is a StatusCodeException reporting Not Found. */ |
| public static boolean isNotFound(Throwable err) { |
| return isStatus(err, Response.SC_NOT_FOUND); |
| } |
| |
| /** True if err is describing a user that is currently anonymous. */ |
| public static boolean isNotSignedIn(Throwable err) { |
| if (err instanceof StatusCodeException) { |
| StatusCodeException sce = (StatusCodeException) err; |
| if (sce.getStatusCode() == Response.SC_UNAUTHORIZED) { |
| return true; |
| } |
| return sce.getStatusCode() == Response.SC_FORBIDDEN |
| && (sce.getEncodedResponse().equals("Authentication required") |
| || sce.getEncodedResponse().startsWith("Must be signed-in")); |
| } |
| return false; |
| } |
| |
| /** True if err is a StatusCodeException with a specific HTTP code. */ |
| public static boolean isStatus(Throwable err, int status) { |
| return err instanceof StatusCodeException |
| && ((StatusCodeException) err).getStatusCode() == status; |
| } |
| |
| /** Is the Gerrit Code Review server likely to return this status? */ |
| public static boolean isExpected(int statusCode) { |
| switch (statusCode) { |
| case SC_UNAVAILABLE: |
| case 400: // Bad Request |
| case 401: // Unauthorized |
| case 403: // Forbidden |
| case 404: // Not Found |
| case 405: // Method Not Allowed |
| case 409: // Conflict |
| case 412: // Precondition Failed |
| case 422: // Unprocessable Entity |
| case 429: // Too Many Requests (RFC 6585) |
| return true; |
| |
| default: |
| // Assume any other code is not expected. These may be |
| // local proxy server errors outside of our control. |
| return false; |
| } |
| } |
| |
| private static class HttpCallback<T extends JavaScriptObject> |
| implements RequestCallback { |
| private final boolean background; |
| private final AsyncCallback<T> cb; |
| |
| HttpCallback(boolean bg, AsyncCallback<T> cb) { |
| this.background = bg; |
| this.cb = cb; |
| } |
| |
| @Override |
| public void onResponseReceived(Request req, Response res) { |
| int status = res.getStatusCode(); |
| if (status == Response.SC_NO_CONTENT) { |
| cb.onSuccess(null); |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| |
| } else if (200 <= status && status < 300) { |
| if (!isJsonBody(res)) { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| cb.onFailure(new StatusCodeException(SC_BAD_RESPONSE, "Expected " |
| + JSON_TYPE + "; received Content-Type: " |
| + res.getHeader("Content-Type"))); |
| return; |
| } |
| |
| T data; |
| try { |
| // javac generics bug |
| data = RestApi.<T>cast(parseJson(res)); |
| } catch (JSONException e) { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| cb.onFailure(new StatusCodeException(SC_BAD_RESPONSE, |
| "Invalid JSON: " + e.getMessage())); |
| return; |
| } |
| |
| cb.onSuccess(data); |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| |
| } else { |
| String msg; |
| if (isTextBody(res)) { |
| msg = res.getText().trim(); |
| } else if (isJsonBody(res)) { |
| JSONValue v; |
| try { |
| v = parseJson(res); |
| } catch (JSONException e) { |
| v = null; |
| } |
| if (v != null && v.isString() != null) { |
| msg = v.isString().stringValue(); |
| } else { |
| msg = trimJsonMagic(res.getText()).trim(); |
| } |
| } else { |
| msg = res.getStatusText(); |
| } |
| |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| cb.onFailure(new StatusCodeException(status, msg)); |
| } |
| } |
| |
| @Override |
| public void onError(Request req, Throwable err) { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcComplete(); |
| } |
| if (err.getMessage().contains("XmlHttpRequest.status")) { |
| cb.onFailure(new StatusCodeException( |
| SC_UNAVAILABLE, |
| RpcConstants.C.errorServerUnavailable())); |
| } else { |
| cb.onFailure(new StatusCodeException(SC_BAD_TRANSPORT, err.getMessage())); |
| } |
| } |
| } |
| |
| private StringBuilder url; |
| private boolean hasQueryParams; |
| private boolean background; |
| private String ifNoneMatch; |
| |
| /** |
| * Initialize a new API call. |
| * <p> |
| * By default the JSON format will be selected by including an HTTP Accept |
| * header in the request. |
| * |
| * @param name URL of the REST resource to access, e.g. {@code "/projects/"} |
| * to list accessible projects from the server. |
| */ |
| public RestApi(String name) { |
| if (name.startsWith("/")) { |
| name = name.substring(1); |
| } |
| |
| url = new StringBuilder(); |
| url.append(GWT.getHostPageBaseURL()); |
| url.append(name); |
| } |
| |
| public RestApi view(String name) { |
| return idRaw(name); |
| } |
| |
| public RestApi id(String id) { |
| return idRaw(URL.encodeQueryString(id)); |
| } |
| |
| public RestApi id(int id) { |
| return idRaw(Integer.toString(id)); |
| } |
| |
| public RestApi idRaw(String name) { |
| if (hasQueryParams) { |
| throw new IllegalStateException(); |
| } |
| if (url.charAt(url.length() - 1) != '/') { |
| url.append('/'); |
| } |
| url.append(name); |
| return this; |
| } |
| |
| public RestApi addParameter(String name, String value) { |
| return addParameterRaw(name, URL.encodeQueryString(value)); |
| } |
| |
| public RestApi addParameter(String name, String... value) { |
| for (String val : value) { |
| addParameter(name, val); |
| } |
| return this; |
| } |
| |
| public RestApi addParameterTrue(String name) { |
| return addParameterRaw(name, null); |
| } |
| |
| public RestApi addParameter(String name, boolean value) { |
| return addParameterRaw(name, value ? "t" : "f"); |
| } |
| |
| public RestApi addParameter(String name, int value) { |
| return addParameterRaw(name, String.valueOf(value)); |
| } |
| |
| public RestApi addParameter(String name, Enum<?> value) { |
| return addParameterRaw(name, value.name()); |
| } |
| |
| public RestApi addParameterRaw(String name, String value) { |
| if (hasQueryParams) { |
| url.append("&"); |
| } else { |
| url.append("?"); |
| hasQueryParams = true; |
| } |
| url.append(name); |
| if (value != null) { |
| url.append("=").append(value); |
| } |
| return this; |
| } |
| |
| public RestApi ifNoneMatch() { |
| return ifNoneMatch("*"); |
| } |
| |
| public RestApi ifNoneMatch(String etag) { |
| ifNoneMatch = etag; |
| return this; |
| } |
| |
| public RestApi background() { |
| background = true; |
| return this; |
| } |
| |
| public String url() { |
| return url.toString(); |
| } |
| |
| public <T extends JavaScriptObject> void get(AsyncCallback<T> cb) { |
| send(GET, cb); |
| } |
| |
| public <T extends JavaScriptObject> void delete(AsyncCallback<T> cb) { |
| send(DELETE, cb); |
| } |
| |
| private <T extends JavaScriptObject> void send( |
| Method method, AsyncCallback<T> cb) { |
| HttpCallback<T> httpCallback = new HttpCallback<T>(background, cb); |
| try { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcStart(); |
| } |
| request(method).sendRequest(null, httpCallback); |
| } catch (RequestException e) { |
| httpCallback.onError(null, e); |
| } |
| } |
| |
| public <T extends JavaScriptObject> void post( |
| JavaScriptObject content, |
| AsyncCallback<T> cb) { |
| sendJSON(POST, content, cb); |
| } |
| |
| public <T extends JavaScriptObject> void post(String content, |
| AsyncCallback<T> cb) { |
| sendRaw(POST, content, cb); |
| } |
| |
| public <T extends JavaScriptObject> void put(AsyncCallback<T> cb) { |
| send(PUT, cb); |
| } |
| |
| public <T extends JavaScriptObject> void put( |
| JavaScriptObject content, |
| AsyncCallback<T> cb) { |
| sendJSON(PUT, content, cb); |
| } |
| |
| private <T extends JavaScriptObject> void sendJSON( |
| Method method, JavaScriptObject content, |
| AsyncCallback<T> cb) { |
| HttpCallback<T> httpCallback = new HttpCallback<T>(background, cb); |
| try { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcStart(); |
| } |
| String body = new JSONObject(content).toString(); |
| RequestBuilder req = request(method); |
| req.setHeader("Content-Type", JSON_UTF8); |
| req.sendRequest(body, httpCallback); |
| } catch (RequestException e) { |
| httpCallback.onError(null, e); |
| } |
| } |
| |
| private <T extends JavaScriptObject> void sendRaw(Method method, String body, |
| AsyncCallback<T> cb) { |
| HttpCallback<T> httpCallback = new HttpCallback<T>(background, cb); |
| try { |
| if (!background) { |
| RpcStatus.INSTANCE.onRpcStart(); |
| } |
| RequestBuilder req = request(method); |
| req.setHeader("Content-Type", TEXT_TYPE); |
| req.sendRequest(body, httpCallback); |
| } catch (RequestException e) { |
| httpCallback.onError(null, e); |
| } |
| } |
| |
| private RequestBuilder request(Method method) { |
| RequestBuilder req = new RequestBuilder(method, url()); |
| if (ifNoneMatch != null) { |
| req.setHeader("If-None-Match", ifNoneMatch); |
| } |
| req.setHeader("Accept", JSON_TYPE); |
| if (Gerrit.getXGerritAuth() != null) { |
| req.setHeader("X-Gerrit-Auth", Gerrit.getXGerritAuth()); |
| } |
| return req; |
| } |
| |
| private static boolean isJsonBody(Response res) { |
| return isContentType(res, JSON_TYPE); |
| } |
| |
| private static boolean isTextBody(Response res) { |
| return isContentType(res, TEXT_TYPE); |
| } |
| |
| private static boolean isContentType(Response res, String want) { |
| String type = res.getHeader("Content-Type"); |
| if (type == null) { |
| return false; |
| } |
| int semi = type.indexOf(';'); |
| if (semi >= 0) { |
| type = type.substring(0, semi).trim(); |
| } |
| return want.equals(type); |
| } |
| |
| private static JSONValue parseJson(Response res) |
| throws JSONException { |
| String json = trimJsonMagic(res.getText()); |
| if (json.isEmpty()) { |
| throw new JSONException("response was empty"); |
| } |
| return JSONParser.parseStrict(json); |
| } |
| |
| private static String trimJsonMagic(String json) { |
| if (json.startsWith(JSON_MAGIC)) { |
| json = json.substring(JSON_MAGIC.length()); |
| } |
| return json; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private static <T extends JavaScriptObject> T cast(JSONValue val) { |
| if (val.isObject() != null) { |
| return (T) val.isObject().getJavaScriptObject(); |
| } else if (val.isArray() != null) { |
| return (T) val.isArray().getJavaScriptObject(); |
| } else if (val.isString() != null) { |
| return (T) NativeString.wrap(val.isString().stringValue()); |
| } else if (val.isNull() != null) { |
| return null; |
| } else { |
| throw new JSONException("unsupported JSON type"); |
| } |
| } |
| } |