content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.chemistry.opencmis.client.bindings.spi.http;
  
  import static org.apache.chemistry.opencmis.commons.impl.CollectionsHelper.isNotEmpty;
  
  import java.io.BufferedOutputStream;
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.math.BigInteger;
  import java.net.Socket;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.zip.GZIPOutputStream;
  
  import javax.net.ssl.HostnameVerifier;
  import javax.net.ssl.SSLException;
  import javax.net.ssl.SSLSocket;
  
  import org.apache.chemistry.opencmis.client.bindings.impl.ClientVersion;
  import org.apache.chemistry.opencmis.client.bindings.impl.CmisBindingsHelper;
  import org.apache.chemistry.opencmis.client.bindings.spi.BindingSession;
  import org.apache.chemistry.opencmis.commons.SessionParameter;
  import org.apache.chemistry.opencmis.commons.exceptions.CmisConnectionException;
  import org.apache.chemistry.opencmis.commons.exceptions.CmisRuntimeException;
  import org.apache.chemistry.opencmis.commons.impl.IOUtils;
  import org.apache.chemistry.opencmis.commons.impl.UrlBuilder;
  import org.apache.chemistry.opencmis.commons.spi.AuthenticationProvider;
  import org.apache.http.Header;
  import org.apache.http.HttpEntity;
  import org.apache.http.HttpResponse;
  import org.apache.http.HttpVersion;
  import org.apache.http.client.HttpClient;
  import org.apache.http.client.methods.HttpDelete;
  import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.client.methods.HttpPut;
  import org.apache.http.client.methods.HttpRequestBase;
  import org.apache.http.conn.ssl.X509HostnameVerifier;
  import org.apache.http.entity.AbstractHttpEntity;
  import org.apache.http.impl.client.DefaultHttpClient;
  import org.apache.http.params.BasicHttpParams;
  import org.apache.http.params.HttpConnectionParams;
  import org.apache.http.params.HttpParams;
  import org.apache.http.params.HttpProtocolParams;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * A {@link HttpInvoker} that uses The Apache HTTP client.
   */
  public abstract class AbstractApacheClientHttpInvoker implements HttpInvoker {
  
      protected static final Logger LOG = LoggerFactory.getLogger(AbstractApacheClientHttpInvoker.class);
  
      protected static final String HTTP_CLIENT = "org.apache.chemistry.opencmis.client.bindings.spi.http.ApacheClientHttpInvoker.httpClient";
      protected static final int BUFFER_SIZE = 2 * 1024 * 1024;
  
      @Override
      public Response invokeGET(UrlBuilder url, BindingSession session) {
          return invoke(url, "GET", null, null, null, session, null, null);
      }
  
      @Override
      public Response invokeGET(UrlBuilder url, BindingSession session, BigInteger offset, BigInteger length) {
          return invoke(url, "GET", null, null, null, session, offset, length);
      }
  
      @Override
      public Response invokePOST(UrlBuilder url, String contentType, Output writer, BindingSession session) {
          return invoke(url, "POST", contentType, null, writer, session, null, null);
      }
  
      @Override
      public Response invokePUT(UrlBuilder url, String contentType, Map<String, String> headers, Output writer,
              BindingSession session) {
          return invoke(url, "PUT", contentType, headers, writer, session, null, null);
      }
  
      @Override
      public Response invokeDELETE(UrlBuilder url, BindingSession session) {
          return invoke(url, "DELETE", null, null, null, session, null, null);
      }
  
      protected Response invoke(UrlBuilder url, String method, String contentType, Map<String, String> headers,
              final Output writer, final BindingSession session, BigInteger offset, BigInteger length) {
          int respCode = -1;
  
          try {
              // log before connect
              if (LOG.isDebugEnabled()) {
                  LOG.debug("Session {}: {} {}", session.getSessionId(), method, url);
              }
  
              // get HTTP client object from session
              DefaultHttpClient httpclient = (DefaultHttpClient) session.get(HTTP_CLIENT);
              if (httpclient == null) {
                  session.writeLock();
                  try {
                      httpclient = (DefaultHttpClient) session.get(HTTP_CLIENT);
                      if (httpclient == null) {
                          httpclient = createHttpClient(url, session);
                          session.put(HTTP_CLIENT, httpclient, true);
                      }
                  } finally {
                      session.writeUnlock();
                  }
              }
  
              HttpRequestBase request = null;
  
              if ("GET".equals(method)) {
                  request = new HttpGet(url.toString());
              } else if ("POST".equals(method)) {
                  request = new HttpPost(url.toString());
              } else if ("PUT".equals(method)) {
                  request = new HttpPut(url.toString());
              } else if ("DELETE".equals(method)) {
                  request = new HttpDelete(url.toString());
              } else {
                  throw new CmisRuntimeException("Invalid HTTP method!");
              }
  
              // set content type
              if (contentType != null) {
                  request.setHeader("Content-Type", contentType);
              }
              // set other headers
              if (headers != null) {
                  for (Map.Entry<String, String> header : headers.entrySet()) {
                      request.addHeader(header.getKey(), header.getValue());
                  }
              }
  
              // authenticate
              AuthenticationProvider authProvider = CmisBindingsHelper.getAuthenticationProvider(session);
              if (authProvider != null) {
                  Map<String, List<String>> httpHeaders = authProvider.getHTTPHeaders(url.toString());
                  if (httpHeaders != null) {
                      for (Map.Entry<String, List<String>> header : httpHeaders.entrySet()) {
                          if (header.getKey() != null && isNotEmpty(header.getValue())) {
                              String key = header.getKey();
                              if (key.equalsIgnoreCase("user-agent")) {
                                  request.setHeader("User-Agent", header.getValue().get(0));
                              } else {
                                  for (String value : header.getValue()) {
                                      if (value != null) {
                                          request.addHeader(key, value);
                                      }
                                  }
                              }
                          }
                      }
                  }
              }
  
              // range
              if ((offset != null) || (length != null)) {
                  StringBuilder sb = new StringBuilder("bytes=");
  
                  if ((offset == null) || (offset.signum() == -1)) {
                      offset = BigInteger.ZERO;
                  }
  
                  sb.append(offset.toString());
                  sb.append('-');
  
                  if ((length != null) && (length.signum() == 1)) {
                      sb.append(offset.add(length.subtract(BigInteger.ONE)).toString());
                  }
  
                  request.setHeader("Range", sb.toString());
              }
  
              // compression
              Object compression = session.get(SessionParameter.COMPRESSION);
              if ((compression != null) && Boolean.parseBoolean(compression.toString())) {
                  request.setHeader("Accept-Encoding", "gzip,deflate");
              }
  
              // locale
              if (session.get(CmisBindingsHelper.ACCEPT_LANGUAGE) instanceof String) {
                  request.setHeader("Accept-Language", session.get(CmisBindingsHelper.ACCEPT_LANGUAGE).toString());
              }
  
              // send data
              if (writer != null) {
                  Object clientCompression = session.get(SessionParameter.CLIENT_COMPRESSION);
                  final boolean clientCompressionFlag = (clientCompression != null)
                          && Boolean.parseBoolean(clientCompression.toString());
                  if (clientCompressionFlag) {
                      request.setHeader("Content-Encoding", "gzip");
                  }
  
                  AbstractHttpEntity streamEntity = new AbstractHttpEntity() {
                      @Override
                      public boolean isChunked() {
                          return true;
                      }
  
                      @Override
                      public boolean isRepeatable() {
                          return false;
                      }
  
                      @Override
                      public long getContentLength() {
                          return -1;
                      }
  
                      @Override
                      public boolean isStreaming() {
                          return false;
                      }
  
                      @Override
                      public InputStream getContent() throws IOException {
                          throw new UnsupportedOperationException();
                      }
  
                      @Override
                      public void writeTo(final OutputStream outstream) throws IOException {
                          OutputStream connOut = null;
  
                          if (clientCompressionFlag) {
                              connOut = new GZIPOutputStream(outstream, 4096);
                          } else {
                              connOut = outstream;
                          }
  
                          OutputStream out = new BufferedOutputStream(connOut, BUFFER_SIZE);
                          try {
                              writer.write(out);
                          } catch (IOException ioe) {
                              throw ioe;
                          } catch (Exception e) {
                              throw new IOException(e);
                          }
                          out.flush();
  
                          if (connOut instanceof GZIPOutputStream) {
                              ((GZIPOutputStream) connOut).finish();
                          }
                      }
                  };
                  ((HttpEntityEnclosingRequestBase) request).setEntity(streamEntity);
              }
  
              // connect
              HttpResponse response = httpclient.execute(request);
              HttpEntity entity = response.getEntity();
  
              // get stream, if present
              respCode = response.getStatusLine().getStatusCode();
              InputStream inputStream = null;
              InputStream errorStream = null;
  
              if (respCode == 200 || respCode == 201 || respCode == 203 || respCode == 206) {
                  if (entity != null) {
                      inputStream = entity.getContent();
                  } else {
                      inputStream = new ByteArrayInputStream(new byte[0]);
                  }
              } else {
                  if (entity != null) {
                      errorStream = entity.getContent();
                  } else {
                      errorStream = new ByteArrayInputStream(new byte[0]);
                  }
              }
  
              // collect headers
              Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
              for (Header header : response.getAllHeaders()) {
                  List<String> values = responseHeaders.get(header.getName());
                  if (values == null) {
                      values = new ArrayList<String>();
                      responseHeaders.put(header.getName(), values);
                  }
                  values.add(header.getValue());
              }
  
              // log after connect
              if (LOG.isTraceEnabled()) {
                  LOG.trace("Session {}: {} {} > Headers: {}", session.getSessionId(), method, url,
                          responseHeaders.toString());
              }
  
              // forward response HTTP headers
              if (authProvider != null) {
                  authProvider.putResponseHeaders(url.toString(), respCode, responseHeaders);
              }
  
              // get the response
              return new Response(respCode, response.getStatusLine().getReasonPhrase(), responseHeaders, inputStream,
                      errorStream);
          } catch (Exception e) {
              throw new CmisConnectionException(url.toString(), respCode, e);
          }
      }
  
      /**
       * Creates default params for the Apache HTTP Client.
       */
      protected HttpParams createDefaultHttpParams(BindingSession session) {
          HttpParams params = new BasicHttpParams();
  
          HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
          HttpProtocolParams.setUserAgent(params,
                  (String) session.get(SessionParameter.USER_AGENT, ClientVersion.OPENCMIS_USER_AGENT));
          HttpProtocolParams.setContentCharset(params, IOUtils.UTF8);
          HttpProtocolParams.setUseExpectContinue(params, true);
  
          HttpConnectionParams.setStaleCheckingEnabled(params, true);
  
          int connectTimeout = session.get(SessionParameter.CONNECT_TIMEOUT, -1);
          if (connectTimeout >= 0) {
              HttpConnectionParams.setConnectionTimeout(params, connectTimeout);
          }
  
          int readTimeout = session.get(SessionParameter.READ_TIMEOUT, -1);
          if (readTimeout >= 0) {
              HttpConnectionParams.setSoTimeout(params, readTimeout);
          }
  
          return params;
      }
  
      /**
       * Verifies a hostname with the given verifier.
       */
      protected void verify(HostnameVerifier verifier, String host, SSLSocket sslSocket) throws IOException {
          try {
              if (verifier instanceof X509HostnameVerifier) {
                  ((X509HostnameVerifier) verifier).verify(host, sslSocket);
              } else {
                  if (!verifier.verify(host, sslSocket.getSession())) {
                      throw new SSLException("Hostname in certificate didn't match: <" + host + ">");
                  }
              }
          } catch (IOException ioe) {
              closeSocket(sslSocket);
              throw ioe;
          }
      }
  
      /**
       * Closes the given socket and ignores exceptions.
       */
      protected void closeSocket(Socket socket) {
          try {
              socket.close();
          } catch (IOException ioe) {
              // ignore
          }
      }
  
      /**
       * Creates the {@link HttpClient} instance.
       */
      protected abstract DefaultHttpClient createHttpClient(UrlBuilder url, BindingSession session);
  }
  