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