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

   1 /*
   2  * Copyright 2009 Electronic Business Systems Ltd.
   3  *
   4  * This file is part of GSS.
   5  *
   6  * GSS is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GSS is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with GSS.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 package gr.ebs.gss.client.rest;
  20
  21 import gr.ebs.gss.client.GSS;
  22 import gr.ebs.gss.client.exceptions.ObjectNotFoundException;
  23 import gr.ebs.gss.client.rest.resource.FileResource;
  24 import gr.ebs.gss.client.rest.resource.FolderResource;
  25 import gr.ebs.gss.client.rest.resource.GroupResource;
  26 import gr.ebs.gss.client.rest.resource.GroupUserResource;
  27 import gr.ebs.gss.client.rest.resource.GroupsResource;
  28 import gr.ebs.gss.client.rest.resource.RestResource;
  29 import gr.ebs.gss.client.rest.resource.SharedResource;
  30 import gr.ebs.gss.client.rest.resource.TrashResource;
  31 import gr.ebs.gss.client.rest.resource.UserResource;
  32
  33 import com.google.gwt.core.client.GWT;
  34 import com.google.gwt.http.client.Request;
  35 import com.google.gwt.http.client.RequestBuilder;
  36 import com.google.gwt.http.client.Response;
  37
  38
  39 /**
  40  * @author kman
  41  *
  42  */
  43 public  abstract class HeadCommand<T extends RestResource> extends RestCommand{
  44
  45         boolean complete = false;
  46         T result = null;
  47         Class<T> aclass;
  48         private boolean requestSent = false;
  49         T cached;
  50         final String path;
  51
  52         public HeadCommand(Class<T> theclass, String pathToGet, T theCached){
  53                 this(theclass, pathToGet, true, theCached);
  54         }
  55
  56         public HeadCommand(Class<T> theClass, String pathToGet, boolean showLoading, T theCached){
  57                 setShowLoadingIndicator(showLoading);
  58                 this.aclass = theClass;
  59                 if(isShowLoadingIndicator())
  60                         GSS.get().showLoadingIndicator();
  61
  62                 if(theClass.equals(FileResource.class))
  63                         path = pathToGet;
  64                 else
  65                         path = fixPath(pathToGet);
  66                 this.cached = theCached;
  67
  68         }
  69
  70         private void sendRequest(){
  71                 if(requestSent)
  72                         return;
  73                 requestSent=true;
  74                 RequestBuilder builder = new RequestBuilder(RequestBuilder.HEAD, path);
  75                 if(cached!=null && cached.getLastModifiedSince() != null){
  76                         GWT.log("ADDING IF MODIFIED HEADERS", null);
  77                         builder.setHeader("If-Modified-Since", cached.getLastModifiedSince());
  78                 }
  79                 try {
  80                         handleHeaders(builder, path);
  81                         builder.sendRequest("", new RestCallback(path) {
  82
  83                                 @Override
  84                                 public Object deserialize(Response response) {
  85                                         return deserializeResponse(path, response);
  86                                 }
  87
  88                                 @Override
  89                                 public void handleError(Request request, Throwable exception) {
  90                                         if(exception instanceof RestException)
  91                                                 if(((RestException)exception).getHttpStatusCode() == 304 && cached != null){
  92                                                         GWT.log("Using cache:"+cached.getUri(), null);
  93                                                         handleSuccess(cached);
  94                                                         return;
  95                                                 }
  96                                         complete = true;
  97                                         HeadCommand.this.onError(exception);
  98                                 }
  99
 100                                 @Override
 101                                 public void handleSuccess(Object object) {
 102                                         result = (T) object;
 103                                         complete = true;
 104                                 }
 105
 106                         });
 107                 } catch (Exception ex) {
 108                         complete = true;
 109                         onError(ex);
 110                 }
 111         }
 112
 113         public boolean isComplete() {
 114                 return complete;
 115         }
 116
 117         public T getResult(){
 118                 return result;
 119         }
 120
 121         @Override
 122         public boolean execute() {
 123                 if(!requestSent)
 124                         sendRequest();
 125                 boolean com = isComplete();
 126                 if(com){
 127                         if(isShowLoadingIndicator())
 128                                 GSS.get().hideLoadingIndicator();
 129                         if(getResult() != null)
 130                                 onComplete();
 131                         else
 132                                 onError(new ObjectNotFoundException("Resource Not Found"));
 133                         return false;
 134                 }
 135                 return true;
 136         }
 137
 138         public  Object deserializeResponse(String aPath, Response response){
 139                 RestResource result1 = null;
 140                 if(aclass.equals(FolderResource.class)){
 141                         result1 = new FolderResource(aPath);
 142                         result1.createFromJSON(response.getText());
 143
 144                 }
 145                 else if(aclass.equals(FileResource.class)){
 146                         result1 = new FileResource(aPath);
 147                         result1.createFromJSON(response.getHeader("X-GSS-Metadata"));
 148                 }
 149                 else if(aclass.equals(GroupsResource.class)){
 150                         result1 = new GroupsResource(aPath);
 151                         result1.createFromJSON(response.getText());
 152                 }
 153                 else if(aclass.equals(TrashResource.class)){
 154                         result1 = new TrashResource(aPath);
 155                         result1.createFromJSON(response.getText());
 156
 157                 }
 158                 else if(aclass.equals(SharedResource.class)){
 159                         result1 = new SharedResource(aPath);
 160                         result1.createFromJSON(response.getText());
 161
 162                 }
 163                 else if(aclass.equals(GroupResource.class)){
 164                         result1 = new GroupResource(aPath);
 165                         result1.createFromJSON(response.getText());
 166
 167                 }
 168                 else if(aclass.equals(GroupUserResource.class)){
 169                         result1 = new GroupUserResource(aPath);
 170                         result1.createFromJSON(response.getText());
 171
 172                 }
 173                 else if(aclass.equals(UserResource.class)){
 174                         result1 = new UserResource(aPath);
 175                         result1.createFromJSON(response.getText());
 176
 177                 }
 178                 return result1;
 179         }
 180 }