Changeset 28382 for main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/DepositorAction.java

Timestamp:

2013-10-10T17:21:30+13:00 (11 years ago)

Author:

davidb

Message:

Elimination of the 'this.doc' field from the Action baseclass and the subclasses that rely on it. For Greenstone3 purposes it is unsafe to create this object in the constructor to the action and then store it for other methods to access. This is because the Greenstone 3 (and in particular calls to 'process' operate in a multi-threaded context, that is managed by the Servlet server (e.g. Tomcat by default). Calls to DOM methods are not guaranteed to be thread safe, this became apparent when we started looking in to an exception that was being thrown, and centred around use of the DOM method 'item(i)'. The change this commit makes is to remove 'this.doc' being stored as a field. A document is now created in the top level of a call to 'process()' and when a DOM reference is needed in a subsequent method an Element variable (typically passed in as a parameter to the method) is used (through 'Document doc = element.getOwnerDocument()') to gain access to the DOM

File:

• main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/DepositorAction.java (modified) (8 diffs)

main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/DepositorAction.java

@@ -43 +43 @@
     {
         Element request = (Element) GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
-
+        Document doc = request.getOwnerDocument();
+        
         UserContext uc = new UserContext((Element) request);
         String currentUsername = uc.getUsername();
 
-        Element responseMessage = this.doc.createElement(GSXML.MESSAGE_ELEM);
-        Element response = GSXML.createBasicResponse(this.doc, this.getClass().getSimpleName());
+        Element responseMessage = doc.createElement(GSXML.MESSAGE_ELEM);
+        Element response = GSXML.createBasicResponse(doc, this.getClass().getSimpleName());
         responseMessage.appendChild(response);
 
@@ -226 +227 @@
             formContainer.appendChild(callToPage);
 
-            Element cachedValueElement = this.doc.createElement("cachedValues");
+            Element cachedValueElement = doc.createElement("cachedValues");
             response.appendChild(cachedValueElement);
             try
@@ -232 +233 @@
                 for (int i = pageNum; i > 0; i--)
                 {
-                    Element page = this.doc.createElement("pageCache");
+                    Element page = doc.createElement("pageCache");
                     page.setAttribute("pageNum", "" + i);
                     String cachedValues = database.getUserData(currentUsername, "DE___" + collection + "___" + i + "___CACHED_VALUES");
                     if (cachedValues != null)
                     {
-                        page.appendChild(this.doc.createTextNode(cachedValues));
+                        page.appendChild(doc.createTextNode(cachedValues));
                         cachedValueElement.appendChild(page);
                     }
@@ -287 +288 @@
                 {
                     ex.printStackTrace();
-                    GSXML.addError(this.doc, responseMessage, "Failed to copy the deposited file into the collection.");
+                    GSXML.addError(doc, responseMessage, "Failed to copy the deposited file into the collection.");
                     return responseMessage;
                 }
@@ -331 +332 @@
                 }
 
-                Element buildMessage = this.doc.createElement(GSXML.MESSAGE_ELEM);
-                Element buildRequest = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, "ImportCollection", uc);
+                Element buildMessage = doc.createElement(GSXML.MESSAGE_ELEM);
+                Element buildRequest = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_PROCESS, "ImportCollection", uc);
                 buildMessage.appendChild(buildRequest);
 
-                Element paramListElem = this.doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
+                Element paramListElem = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
                 buildRequest.appendChild(paramListElem);
 
-                Element collectionParam = this.doc.createElement(GSXML.PARAM_ELEM);
+                Element collectionParam = doc.createElement(GSXML.PARAM_ELEM);
                 paramListElem.appendChild(collectionParam);
                 collectionParam.setAttribute(GSXML.NAME_ATT, GSXML.COLLECTION_ATT);
                 collectionParam.setAttribute(GSXML.VALUE_ATT, collection);
 
-                Element documentsParam = this.doc.createElement(GSXML.PARAM_ELEM);
+                Element documentsParam = doc.createElement(GSXML.PARAM_ELEM);
                 paramListElem.appendChild(documentsParam);
                 documentsParam.setAttribute(GSXML.NAME_ATT, "documents");
@@ -350 +351 @@
                 Element buildResponseMessage = (Element) this.mr.process(buildMessage);
 
-                response.appendChild(this.doc.importNode(buildResponseMessage, true));
+                response.appendChild(doc.importNode(buildResponseMessage, true));
             }
         }
@@ -364 +365 @@
         else
         {
-            Element depositorPage = this.doc.createElement("depositorPage");
+            Element depositorPage = doc.createElement("depositorPage");
             response.appendChild(depositorPage);
 
-            Element collList = getCollectionsInSite();
-            depositorPage.appendChild(this.doc.importNode(collList, true));
+            Element collList = getCollectionsInSite(doc);
+            depositorPage.appendChild(doc.importNode(collList, true));
         }
 
@@ -374 +375 @@
     }
 
-    public Element getCollectionsInSite()
+    public Element getCollectionsInSite(Document doc) 
     {
-        Element message = this.doc.createElement(GSXML.MESSAGE_ELEM);
-        Element request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_DESCRIBE, "", new UserContext());
+        Element message = doc.createElement(GSXML.MESSAGE_ELEM);
+        Element request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, "", new UserContext());
         message.appendChild(request);
         Element responseMessage = (Element) this.mr.process(message);