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.Response;
  36
  37
  38 /**
  39  * @author kman
  40  *
  41  */
  42 public  abstract class HeadCommand<T extends RestResource> extends RestCommand{
  43
  44         boolean complete = false;
  45         T result = null;
  46         Class<T> aclass;
  47         private boolean requestSent = false;
  48         T cached;
  49         final String path;
  50
  51         public HeadCommand(Class<T> theclass, String pathToGet, T theCached){
  52                 this(theclass, pathToGet, true, theCached);
  53         }
  54
  55         public HeadCommand(Class<T> theClass, String pathToGet, boolean showLoading, T theCached){
  56                 setShowLoadingIndicator(showLoading);
  57                 this.aclass = theClass;
  58                 if(isShowLoadingIndicator())
  59                         GSS.get().showLoadingIndicator();
  60
  61                 if(theClass.equals(FileResource.class))
  62                         path = pathToGet;
  63                 else
  64                         path = fixPath(pathToGet);
  65                 this.cached = theCached;
  66
  67         }
  68
  69         private void sendRequest(){
  70                 if(requestSent)
  71                         return;
  72                 requestSent=true;
  73                 RestRequestBuilder builder = new RestRequestBuilder("HEAD", path);
  74                 if(cached!=null && cached.getLastModifiedSince() != null){
  75                         GWT.log("ADDING IF MODIFIED HEADERS", null);
  76                         builder.setHeader("If-Modified-Since", cached.getLastModifiedSince());
  77                 }
  78                 try {
  79                         handleHeaders(builder, path);
  80                         builder.sendRequest("", new RestCallback(path) {
  81
  82                                 @Override
  83                                 public Object deserialize(Response response) {
  84                                         return deserializeResponse(path, response);
  85                                 }
  86
  87                                 @Override
  88                                 public void handleError(Request request, Throwable exception) {
  89                                         if(exception instanceof RestException)
  90                                                 if(((RestException)exception).getHttpStatusCode() == 304 && cached != null){
  91                                                         GWT.log("Using cache:"+cached.getUri(), null);
  92                                                         handleSuccess(cached);
  93                                                         return;
  94                                                 }
  95                                         complete = true;
  96                                         HeadCommand.this.onError(exception);
  97                                 }
  98
  99                                 @Override
 100                                 public void handleSuccess(Object object) {
 101                                         result = (T) object;
 102                                         complete = true;
 103                                 }
 104
 105                         });
 106                 } catch (Exception ex) {
 107                         complete = true;
 108                         onError(ex);
 109                 }
 110         }
 111
 112         public boolean isComplete() {
 113                 return complete;
 114         }
 115
 116         public T getResult(){
 117                 return result;
 118         }
 119
 120         public boolean execute() {
 121                 if(!requestSent)
 122                         sendRequest();
 123                 boolean com = isComplete();
 124                 if(com){
 125                         if(isShowLoadingIndicator())
 126                                 GSS.get().hideLoadingIndicator();
 127                         if(getResult() != null)
 128                                 onComplete();
 129                         else
 130                                 onError(new ObjectNotFoundException("Resource Not Found"));
 131                         return false;
 132                 }
 133                 return true;
 134         }
 135
 136         public  Object deserializeResponse(String aPath, Response response){
 137                 RestResource result1 = null;
 138                 if(aclass.equals(FolderResource.class)){
 139                         result1 = new FolderResource(aPath);
 140                         result1.createFromJSON(response.getText());
 141
 142                 }
 143                 else if(aclass.equals(FileResource.class)){
 144                         result1 = new FileResource(aPath);
 145                         result1.createFromJSON(response.getHeader("X-GSS-Metadata"));
 146                 }
 147                 else if(aclass.equals(GroupsResource.class)){
 148                         result1 = new GroupsResource(aPath);
 149                         result1.createFromJSON(response.getText());
 150                 }
 151                 else if(aclass.equals(TrashResource.class)){
 152                         result1 = new TrashResource(aPath);
 153                         result1.createFromJSON(response.getText());
 154
 155                 }
 156                 else if(aclass.equals(SharedResource.class)){
 157                         result1 = new SharedResource(aPath);
 158                         result1.createFromJSON(response.getText());
 159
 160                 }
 161                 else if(aclass.equals(GroupResource.class)){
 162                         result1 = new GroupResource(aPath);
 163                         result1.createFromJSON(response.getText());
 164
 165                 }
 166                 else if(aclass.equals(GroupUserResource.class)){
 167                         result1 = new GroupUserResource(aPath);
 168                         result1.createFromJSON(response.getText());
 169
 170                 }
 171                 else if(aclass.equals(UserResource.class)){
 172                         result1 = new UserResource(aPath);
 173                         result1.createFromJSON(response.getText());
 174
 175                 }
 176                 return result1;
 177         }
 178 }