Java tutorial
/* * Copyright 2007 Yusuke Yamamoto * * 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 facebook4j.internal.http; import facebook4j.FacebookException; import facebook4j.conf.ConfigurationContext; import facebook4j.internal.logging.Logger; import facebook4j.internal.org.json.JSONArray; import facebook4j.internal.org.json.JSONException; import facebook4j.internal.org.json.JSONObject; import facebook4j.internal.org.json.JSONTokener; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; import java.util.List; import java.util.Map; /** * A data class representing HTTP Response * * @author Yusuke Yamamoto - yusuke at mac.com */ public abstract class HttpResponse { private static final Logger logger = Logger.getLogger(HttpResponseImpl.class); protected final HttpClientConfiguration CONF; HttpResponse() { this.CONF = ConfigurationContext.getInstance(); } public HttpResponse(HttpClientConfiguration conf) { this.CONF = conf; } protected int statusCode; protected String responseAsString = null; protected InputStream is; private boolean streamConsumed = false; public int getStatusCode() { return statusCode; } public abstract String getResponseHeader(String name); public abstract Map<String, List<String>> getResponseHeaderFields(); /** * Returns the response stream.<br> * This method cannot be called after calling asString() or asDcoument()<br> * It is suggested to call disconnect() after consuming the stream. * <p/> * Disconnects the internal HttpURLConnection silently. * * @return response body stream * @throws FacebookException * @see #disconnect() */ public InputStream asStream() { if (streamConsumed) { throw new IllegalStateException("Stream has already been consumed."); } return is; } /** * Returns the response body as string.<br> * Disconnects the internal HttpURLConnection silently. * * @return response body * @throws FacebookException */ public String asString() throws FacebookException { if (null == responseAsString) { BufferedReader br = null; InputStream stream = null; try { stream = asStream(); if (null == stream) { return null; } br = new BufferedReader(new InputStreamReader(stream, "UTF-8")); StringBuilder buf = new StringBuilder(); String line; while ((line = br.readLine()) != null) { buf.append(line).append("\n"); } this.responseAsString = buf.toString(); logger.debug(responseAsString); stream.close(); streamConsumed = true; } catch (IOException ioe) { throw new FacebookException(ioe.getMessage(), ioe); } finally { if (stream != null) { try { stream.close(); } catch (IOException ignore) { } } if (br != null) { try { br.close(); } catch (IOException ignore) { } } disconnectForcibly(); } } return responseAsString; } private JSONObject json = null; /** * Returns the response body as facebook4j.internal.org.json.JSONObject.<br> * Disconnects the internal HttpURLConnection silently. * * @return response body as facebook4j.internal.org.json.JSONObject * @throws FacebookException */ public JSONObject asJSONObject() throws FacebookException { if (json == null) { Reader reader = null; try { if (responseAsString == null) { reader = asReader(); json = new JSONObject(new JSONTokener(reader)); } else { json = new JSONObject(responseAsString); } if (CONF.isPrettyDebugEnabled()) { logger.debug(json.toString(1)); } else { logger.debug(responseAsString != null ? responseAsString : json.toString()); } } catch (JSONException jsone) { if (responseAsString == null) { throw new FacebookException(jsone.getMessage(), jsone); } else { throw new FacebookException(jsone.getMessage() + ":" + this.responseAsString, jsone); } } finally { if (reader != null) { try { reader.close(); } catch (IOException ignore) { } } disconnectForcibly(); } } return json; } private JSONArray jsonArray = null; /** * Returns the response body as facebook4j.internal.org.json.JSONArray.<br> * Disconnects the internal HttpURLConnection silently. * * @return response body as facebook4j.internal.org.json.JSONArray * @throws FacebookException */ public JSONArray asJSONArray() throws FacebookException { if (jsonArray == null) { Reader reader = null; try { if (responseAsString == null) { reader = asReader(); jsonArray = new JSONArray(new JSONTokener(reader)); } else { jsonArray = new JSONArray(responseAsString); } if (CONF.isPrettyDebugEnabled()) { logger.debug(jsonArray.toString(1)); } else { logger.debug(responseAsString != null ? responseAsString : jsonArray.toString()); } } catch (JSONException jsone) { if (logger.isDebugEnabled()) { throw new FacebookException(jsone.getMessage() + ":" + this.responseAsString, jsone); } else { throw new FacebookException(jsone.getMessage(), jsone); } } finally { if (reader != null) { try { reader.close(); } catch (IOException ignore) { } } disconnectForcibly(); } } return jsonArray; } public Reader asReader() { try { return new BufferedReader(new InputStreamReader(is, "UTF-8")); } catch (java.io.UnsupportedEncodingException uee) { return new InputStreamReader(is); } } private void disconnectForcibly() { try { disconnect(); } catch (Exception ignore) { } } public abstract void disconnect() throws IOException; @Override public String toString() { return "HttpResponse{" + "statusCode=" + statusCode + ", responseAsString='" + responseAsString + '\'' + ", is=" + is + ", streamConsumed=" + streamConsumed + '}'; } }