code.grnet.gr Git - pithos-web-client/blob - src/gr/grnet/pithos/web/client/rest/HeadCommand.java

   1 /*
   2  * Copyright 2011 GRNET S.A. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or
   5  * without modification, are permitted provided that the following
   6  * conditions are met:
   7  *
   8  *   1. Redistributions of source code must retain the above
   9  *      copyright notice, this list of conditions and the following
  10  *      disclaimer.
  11  *
  12  *   2. Redistributions in binary form must reproduce the above
  13  *      copyright notice, this list of conditions and the following
  14  *      disclaimer in the documentation and/or other materials
  15  *      provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
  18  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  20  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
  21  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  24  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  27  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * The views and conclusions contained in the software and
  31  * documentation are those of the authors and should not be
  32  * interpreted as representing official policies, either expressed
  33  * or implied, of GRNET S.A.
  34  */
  35 package gr.grnet.pithos.web.client.rest;
  36
  37 import gr.grnet.pithos.web.client.Pithos;
  38 import gr.grnet.pithos.web.client.ObjectNotFoundException;
  39 import gr.grnet.pithos.web.client.rest.resource.FileResource;
  40 import gr.grnet.pithos.web.client.rest.resource.FolderResource;
  41 import gr.grnet.pithos.web.client.rest.resource.GroupResource;
  42 import gr.grnet.pithos.web.client.rest.resource.GroupUserResource;
  43 import gr.grnet.pithos.web.client.rest.resource.GroupsResource;
  44 import gr.grnet.pithos.web.client.rest.resource.RestResource;
  45 import gr.grnet.pithos.web.client.rest.resource.SharedResource;
  46 import gr.grnet.pithos.web.client.rest.resource.TrashResource;
  47 import gr.grnet.pithos.web.client.rest.resource.UserResource;
  48
  49 import com.google.gwt.core.client.GWT;
  50 import com.google.gwt.http.client.Request;
  51 import com.google.gwt.http.client.RequestBuilder;
  52 import com.google.gwt.http.client.Response;
  53
  54
  55 public  abstract class HeadCommand<T extends RestResource> extends RestCommand{
  56
  57         boolean complete = false;
  58         T result = null;
  59         Class<T> aclass;
  60         private boolean requestSent = false;
  61         T cached;
  62         final String path;
  63
  64         public HeadCommand(Class<T> theclass, String pathToGet, T theCached){
  65                 this(theclass, pathToGet, true, theCached);
  66         }
  67
  68         public HeadCommand(Class<T> theClass, String pathToGet, boolean showLoading, T theCached){
  69                 setShowLoadingIndicator(showLoading);
  70                 this.aclass = theClass;
  71                 if(isShowLoadingIndicator())
  72                         Pithos.get().showLoadingIndicator("Getting ",pathToGet);
  73
  74                 if(theClass.equals(FileResource.class))
  75                         path = pathToGet;
  76                 else
  77                         path = fixPath(pathToGet);
  78                 this.cached = theCached;
  79
  80         }
  81
  82         private void sendRequest(){
  83                 if(requestSent)
  84                         return;
  85                 requestSent=true;
  86                 RequestBuilder builder = new RequestBuilder(RequestBuilder.HEAD, path);
  87                 if(cached!=null && cached.getLastModifiedSince() != null){
  88                         GWT.log("ADDING IF MODIFIED HEADERS", null);
  89                         builder.setHeader("If-Modified-Since", cached.getLastModifiedSince());
  90                 }
  91                 try {
  92                         handleHeaders(builder, path);
  93                         builder.sendRequest("", new RestCallback(path) {
  94
  95                                 @Override
  96                                 public Object deserialize(Response response) {
  97                                         return deserializeResponse(path, response);
  98                                 }
  99
 100                                 @Override
 101                                 public void handleError(Request request, Throwable exception) {
 102                                         if(exception instanceof RestException)
 103                                                 if(((RestException)exception).getHttpStatusCode() == 304 && cached != null){
 104                                                         GWT.log("Using cache:"+cached.getUri(), null);
 105                                                         handleSuccess(cached);
 106                                                         return;
 107                                                 }
 108                                         complete = true;
 109                                         HeadCommand.this.onError(exception);
 110                                 }
 111
 112                                 @Override
 113                                 public void handleSuccess(Object object) {
 114                                         result = (T) object;
 115                                         complete = true;
 116                                 }
 117
 118                         });
 119                 } catch (Exception ex) {
 120                         complete = true;
 121                         onError(ex);
 122                 }
 123         }
 124
 125         public boolean isComplete() {
 126                 return complete;
 127         }
 128
 129         public T getResult(){
 130                 return result;
 131         }
 132
 133         @Override
 134         public boolean execute() {
 135                 if(!requestSent)
 136                         sendRequest();
 137                 boolean com = isComplete();
 138                 if(com){
 139                         if(isShowLoadingIndicator())
 140                                 Pithos.get().hideLoadingIndicator();
 141                         if(getResult() != null)
 142                                 onComplete();
 143                         else
 144                                 onError(new ObjectNotFoundException("Resource Not Found"));
 145                         return false;
 146                 }
 147                 return true;
 148         }
 149
 150         public  Object deserializeResponse(String aPath, Response response){
 151                 RestResource result1 = null;
 152                 if(aclass.equals(FolderResource.class)){
 153                         result1 = new FolderResource(aPath);
 154                         result1.createFromJSON(response.getText());
 155
 156                 }
 157                 else if(aclass.equals(FileResource.class)){
 158                         result1 = new FileResource(aPath);
 159                         result1.createFromJSON(response.getHeader("X-Pithos-Metadata"));
 160                 }
 161                 else if(aclass.equals(GroupsResource.class)){
 162                         result1 = new GroupsResource(aPath);
 163                         result1.createFromJSON(response.getText());
 164                 }
 165                 else if(aclass.equals(TrashResource.class)){
 166                         result1 = new TrashResource(aPath);
 167                         result1.createFromJSON(response.getText());
 168
 169                 }
 170                 else if(aclass.equals(SharedResource.class)){
 171                         result1 = new SharedResource(aPath);
 172                         result1.createFromJSON(response.getText());
 173
 174                 }
 175                 else if(aclass.equals(GroupResource.class)){
 176                         result1 = new GroupResource(aPath);
 177                         result1.createFromJSON(response.getText());
 178
 179                 }
 180                 else if(aclass.equals(GroupUserResource.class)){
 181                         result1 = new GroupUserResource(aPath);
 182                         result1.createFromJSON(response.getText());
 183
 184                 }
 185                 else if(aclass.equals(UserResource.class)){
 186                         result1 = new UserResource(aPath);
 187                         result1.createFromJSON(response.getText());
 188
 189                 }
 190                 return result1;
 191         }
 192 }