code.grnet.gr Git - pithos/blob - src/gr/ebs/gss/web/client/rest/GetCommand.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.web.client.rest;
  20
  21 import gr.ebs.gss.web.client.GSS;
  22 import gr.ebs.gss.web.client.rest.resource.FileResource;
  23 import gr.ebs.gss.web.client.rest.resource.FolderResource;
  24 import gr.ebs.gss.web.client.rest.resource.GroupResource;
  25 import gr.ebs.gss.web.client.rest.resource.GroupUserResource;
  26 import gr.ebs.gss.web.client.rest.resource.GroupsResource;
  27 import gr.ebs.gss.web.client.rest.resource.OtherUserResource;
  28 import gr.ebs.gss.web.client.rest.resource.OthersResource;
  29 import gr.ebs.gss.web.client.rest.resource.RestResource;
  30 import gr.ebs.gss.web.client.rest.resource.SearchResource;
  31 import gr.ebs.gss.web.client.rest.resource.SharedResource;
  32 import gr.ebs.gss.web.client.rest.resource.TagsResource;
  33 import gr.ebs.gss.web.client.rest.resource.TrashResource;
  34 import gr.ebs.gss.web.client.rest.resource.UploadStatusResource;
  35 import gr.ebs.gss.web.client.rest.resource.UserResource;
  36 import gr.ebs.gss.web.client.rest.resource.UserSearchResource;
  37
  38 import java.util.HashMap;
  39 import java.util.Map;
  40
  41 import com.google.gwt.core.client.GWT;
  42 import com.google.gwt.http.client.Request;
  43 import com.google.gwt.http.client.RequestBuilder;
  44 import com.google.gwt.http.client.Response;
  45
  46 /**
  47  * @author kman
  48  */
  49 public abstract class GetCommand<T extends RestResource> extends RestCommand{
  50
  51         boolean complete = false;
  52         T result = null;
  53         Throwable exception = null;
  54         Class<T> aclass;
  55         private final String path;
  56         private String username;
  57         private boolean requestSent = false;
  58         T cached;
  59
  60         private static final long MAX_CACHE_AGE = 1000;
  61
  62         private static class RequestData {
  63                 public String path;
  64                 public String username;
  65
  66                 public RequestData(String _path, String _username) {
  67                         path = _path;
  68                         username = _username;
  69                 }
  70
  71                 @Override
  72                 public int hashCode() {
  73                         final int prime = 31;
  74                         int result = 1;
  75                         result = prime * result + ((path == null) ? 0 : path.hashCode());
  76                         result = prime * result + ((username == null) ? 0 : username.hashCode());
  77                         return result;
  78                 }
  79
  80                 @Override
  81                 public boolean equals(Object obj) {
  82                         if (this == obj)
  83                                 return true;
  84                         if (obj == null)
  85                                 return false;
  86                         if (getClass() != obj.getClass())
  87                                 return false;
  88                         RequestData other = (RequestData) obj;
  89                         if (path == null) {
  90                                 if (other.path != null)
  91                                         return false;
  92                         } else if (!path.equals(other.path))
  93                                 return false;
  94                         if (username == null) {
  95                                 if (other.username != null)
  96                                         return false;
  97                         } else if (!username.equals(other.username))
  98                                 return false;
  99                         return true;
 100                 }
 101         }
 102
 103         private static class ResponseData {
 104                 public long timestamp;
 105                 public Object result;
 106                 public ResponseData(long _timestamp, Object _result) {
 107                         timestamp = _timestamp;
 108                         result = _result;
 109                 }
 110         }
 111
 112         private static Map<RequestData, ResponseData> cache = new HashMap<RequestData, ResponseData>();
 113
 114
 115         public GetCommand(Class<T> theclass, String pathToGet, T theCached){
 116                 this(theclass, pathToGet, true, theCached);
 117         }
 118
 119         public GetCommand(Class<T> theclass, String pathToGet, boolean showLoading, T theCached){
 120                 setShowLoadingIndicator(showLoading);
 121                 if(isShowLoadingIndicator())
 122                         GSS.get().showLoadingIndicator();
 123                 this.aclass = theclass;
 124                 if(pathToGet.indexOf("?") != -1)
 125                         path = pathToGet;
 126                 else
 127                         path =fixPath(pathToGet);
 128                 this.cached = theCached;
 129         }
 130
 131         public GetCommand(Class<T> theclass, String aUsername , String pathToGet, T theCached){
 132                 this(theclass, aUsername, pathToGet, true, theCached);
 133         }
 134
 135         public GetCommand(Class<T> theclass, String aUsername , String pathToGet, boolean showLoading, T theCached){
 136                 setShowLoadingIndicator(showLoading);
 137                 if(isShowLoadingIndicator())
 138                         GSS.get().showLoadingIndicator();
 139                 this.aclass = theclass;
 140                 path = fixPath(pathToGet);
 141                 this.username = aUsername;
 142                 this.cached = theCached;
 143         }
 144
 145         private void sendRequest(){
 146                 if(requestSent)
 147                         return;
 148                 requestSent=true;
 149                 RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, path);
 150                 if(cached!=null && cached.getLastModifiedSince() != null)
 151                         builder.setHeader("If-Modified-Since", cached.getLastModifiedSince());
 152                 try {
 153                         if(username == null)
 154                                 handleHeaders(builder, path);
 155                         else
 156                                 handleHeaders(username, builder, path);
 157                         builder.sendRequest("", new RestCallback(path) {
 158
 159                                 @Override
 160                                 public Object deserialize(Response response) {
 161                                         return deserializeResponse(path, response);
 162                                 }
 163
 164                                 @Override
 165                                 public void handleError(Request request, Throwable _exception) {
 166                                         result = null;
 167                                         complete = true;
 168                                         exception = _exception;
 169                                         if(_exception instanceof RestException)
 170                                                 if(((RestException)_exception).getHttpStatusCode() == 304 && cached != null){
 171                                                         GWT.log("Using cache:"+cached.getUri(), null);
 172                                                         handleSuccess(cached);
 173                                                         return;
 174                                                 }
 175
 176                                 }
 177
 178                                 @Override
 179                                 public void handleSuccess(Object object) {
 180                                         result = (T) object;
 181                                         complete = true;
 182                                 }
 183
 184                         });
 185                 } catch (Exception ex) {
 186                         complete = true;
 187                         exception = ex;
 188                 }
 189         }
 190         public boolean isComplete() {
 191                 return complete;
 192         }
 193
 194         public T getResult(){
 195                 return result;
 196         }
 197
 198         @Override
 199         public boolean execute() {
 200                 boolean com = isComplete();
 201                 RequestData key = new RequestData(path, username);
 202                 if (!com) {
 203                         if (cache.containsKey(key)) {
 204                                 ResponseData resp = cache.get(key);
 205                                 if (resp==null) {
 206                                         return true;
 207                                 }
 208
 209                                 // Cache hit
 210                                 if (System.currentTimeMillis()-resp.timestamp>MAX_CACHE_AGE) {
 211                                         // Cache stale, remove
 212                                         cache.put(key,null);
 213                                 }
 214                                 else {
 215                                         // Use cache data
 216                                         if(isShowLoadingIndicator())
 217                                                 GSS.get().hideLoadingIndicator();
 218                                         if (resp.result instanceof Throwable) {
 219                                                 // Error to be handled
 220                                                 Throwable ex = (Throwable) resp.result;
 221                                                 onError(ex);
 222                                                 return false;
 223                                         }
 224                                         result = (T) resp.result;
 225                                         if (result != null) {
 226                                                 onComplete();
 227                                         }
 228                                         complete = true;
 229                                         return false;
 230                                 }
 231                         }
 232
 233                         if(!requestSent) {
 234                                 cache.put(key,null);
 235                                 sendRequest();
 236                         }
 237                 }
 238
 239                 if(com){
 240                         if(isShowLoadingIndicator())
 241                                 GSS.get().hideLoadingIndicator();
 242                         if(getResult() != null) {
 243                                 // Add to cache
 244                                 cache.put(key, new ResponseData(System.currentTimeMillis(), getResult()));
 245                                 onComplete();
 246                         }
 247                         else {
 248                                 cache.put(key, new ResponseData(System.currentTimeMillis(), exception));
 249                                 onError(exception);
 250                         }
 251                         return false;
 252                 }
 253                 return true;
 254         }
 255
 256         public Object deserializeResponse(String aPath, Response response) {
 257                 RestResource result1 = null;
 258                 if(aclass.equals(FolderResource.class)){
 259                         result1 = new FolderResource(aPath);
 260                         result1.createFromJSON(response.getText());
 261                 }
 262                 else if(aclass.equals(FileResource.class)){
 263                         result1 = new FileResource(aPath);
 264                         result1.createFromJSON(response.getHeader("X-GSS-Metadata"));
 265                 }
 266                 else if(aclass.equals(GroupsResource.class)){
 267                         result1 = new GroupsResource(aPath);
 268                         result1.createFromJSON(response.getText());
 269                 }
 270                 else if(aclass.equals(TrashResource.class)){
 271                         result1 = new TrashResource(aPath);
 272                         result1.createFromJSON(response.getText());
 273                 }
 274                 else if(aclass.equals(SharedResource.class)){
 275                         result1 = new SharedResource(aPath);
 276                         result1.createFromJSON(response.getText());
 277                 }
 278                 else if(aclass.equals(OthersResource.class)){
 279                         result1 = new OthersResource(aPath);
 280                         result1.createFromJSON(response.getText());
 281                 }
 282                 else if(aclass.equals(OtherUserResource.class)){
 283                         result1 = new OtherUserResource(aPath);
 284                         result1.createFromJSON(response.getText());
 285                 }
 286                 else if(aclass.equals(GroupResource.class)){
 287                         result1 = new GroupResource(aPath);
 288                         result1.createFromJSON(response.getText());
 289                 }
 290                 else if(aclass.equals(GroupUserResource.class)){
 291                         result1 = new GroupUserResource(aPath);
 292                         result1.createFromJSON(response.getText());
 293                 }
 294                 else if(aclass.equals(UserResource.class)){
 295                         result1 = new UserResource(aPath);
 296                         result1.createFromJSON(response.getText());
 297                 }
 298                 else if(aclass.equals(TagsResource.class)){
 299                         result1 = new TagsResource(aPath);
 300                         result1.createFromJSON(response.getText());
 301                 }
 302                 else if(aclass.equals(SearchResource.class)){
 303                         result1 = new SearchResource(aPath);
 304                         result1.createFromJSON(response.getText());
 305                 }
 306                 else if(aclass.equals(UserSearchResource.class)){
 307                         result1 = new UserSearchResource(aPath);
 308                         result1.createFromJSON(response.getText());
 309                 }
 310                 else if(aclass.equals(UploadStatusResource.class)){
 311                         result1 = new UploadStatusResource(aPath);
 312                         result1.createFromJSON(response.getText());
 313                 }
 314                 return result1;
 315         }
 316
 317         public T getCached() {
 318                 return cached;
 319         }
 320
 321         public void setCached(T theCached) {
 322                 this.cached = theCached;
 323         }
 324
 325         public boolean usedCachedVersion(){
 326                 if(exception !=null && exception instanceof RestException)
 327                         if(((RestException)exception).getHttpStatusCode() == 304){
 328                                 return true;
 329                         }
 330                 return false;
 331         }
 332 }