src/com/owncloud/android/operations/ExistenceCheckOperation.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012 ownCloud Inc.
   3  *
   4  *   This program is free software: you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License version 2,
   6  *   as published by the Free Software Foundation.
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details.
  12  *
  13  *   You should have received a copy of the GNU General Public License
  14  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  */
  17
  18 package com.owncloud.android.operations;
  19
  20 import org.apache.commons.httpclient.HttpStatus;
  21 import org.apache.commons.httpclient.methods.HeadMethod;
  22
  23 import com.owncloud.android.Log_OC;
  24
  25 import eu.alefzero.webdav.WebdavClient;
  26 import eu.alefzero.webdav.WebdavUtils;
  27 import android.content.Context;
  28 import android.net.ConnectivityManager;
  29
  30 /**
  31  * Operation to check the existence or absence of a path in a remote server.
  32  *
  33  * @author David A. Velasco
  34  */
  35 public class ExistenceCheckOperation extends RemoteOperation {
  36
  37     /** Maximum time to wait for a response from the server in MILLISECONDs.  */
  38     public static final int TIMEOUT = 10000;
  39
  40     private static final String TAG = ExistenceCheckOperation.class.getSimpleName();
  41
  42     private String mPath;
  43     private Context mContext;
  44     private boolean mSuccessIfAbsent;
  45
  46
  47     /**
  48      * Full constructor. Success of the operation will depend upon the value of successIfAbsent.
  49      *
  50      * @param path              Path to append to the URL owned by the client instance.
  51      * @param context           Android application context.
  52      * @param successIfAbsent   When 'true', the operation finishes in success if the path does NOT exist in the remote server (HTTP 404).
  53      */
  54     public ExistenceCheckOperation(String path, Context context, boolean successIfAbsent) {
  55         mPath = (path != null) ? path : "";
  56         mContext = context;
  57         mSuccessIfAbsent = successIfAbsent;
  58     }
  59
  60
  61         @Override
  62         protected RemoteOperationResult run(WebdavClient client) {
  63         if (!isOnline()) {
  64             return new RemoteOperationResult(RemoteOperationResult.ResultCode.NO_NETWORK_CONNECTION);
  65         }
  66         RemoteOperationResult result = null;
  67         HeadMethod head = null;
  68         try {
  69             head = new HeadMethod(client.getBaseUri() + WebdavUtils.encodePath(mPath));
  70             int status = client.executeMethod(head, TIMEOUT, TIMEOUT);
  71             client.exhaustResponse(head.getResponseBodyAsStream());
  72             boolean success = (status == HttpStatus.SC_OK && !mSuccessIfAbsent) || (status == HttpStatus.SC_NOT_FOUND && mSuccessIfAbsent);
  73             result = new RemoteOperationResult(success, status, head.getResponseHeaders());
  74             Log_OC.d(TAG, "Existence check for " + client.getBaseUri() + WebdavUtils.encodePath(mPath) + " targeting for " + (mSuccessIfAbsent ? " absence " : " existence ") + "finished with HTTP status " + status + (!success?"(FAIL)":""));
  75
  76         } catch (Exception e) {
  77             result = new RemoteOperationResult(e);
  78             Log_OC.e(TAG, "Existence check for " + client.getBaseUri() + WebdavUtils.encodePath(mPath) + " targeting for " + (mSuccessIfAbsent ? " absence " : " existence ") + ": " + result.getLogMessage(), result.getException());
  79
  80         } finally {
  81             if (head != null)
  82                 head.releaseConnection();
  83         }
  84         return result;
  85         }
  86
  87     private boolean isOnline() {
  88         ConnectivityManager cm = (ConnectivityManager) mContext
  89                 .getSystemService(Context.CONNECTIVITY_SERVICE);
  90         return cm != null && cm.getActiveNetworkInfo() != null
  91                 && cm.getActiveNetworkInfo().isConnectedOrConnecting();
  92     }
  93
  94
  95 }