Allow reinitializatoin of ProjectManager singleton - fixes #787

main/src/com/google/refine/history/HistoryEntry.java

@@ -40,6 +40,8 @@ import java.util.Properties;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.json.JSONWriter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.google.refine.Jsonizable;
 import com.google.refine.ProjectManager;
@@ -53,6 +55,7 @@ import com.google.refine.util.ParsingUtilities;
  * obtain information about a change without actually loading the change.
  */
 public class HistoryEntry implements Jsonizable {
+    final static Logger logger = LoggerFactory.getLogger("HistoryEntry");
     final public long   id;
     final public long   projectID;
     final public String description;
@@ -82,13 +85,7 @@ public class HistoryEntry implements Jsonizable {
     }
 
     public HistoryEntry(long id, Project project, String description, AbstractOperation operation, Change change) {
-        this.id = id;
+        this(id,project.id,description,operation,new Date());
-        this.projectID = project.id;
-        this.description = description;
-        this.operation = operation;
-        this.time = new Date();
-
-        this._manager = ProjectManager.singleton.getHistoryEntryManager();
         setChange(change);
     }
 
@@ -99,6 +96,10 @@ public class HistoryEntry implements Jsonizable {
         this.operation = operation;
         this.time = time;
         this._manager = ProjectManager.singleton.getHistoryEntryManager();
+        if (this._manager == null) {
+            logger.error("Failed to get history entry manager from project manager: " 
+                    + ProjectManager.singleton );
+        }
     }
 
     @Override

main/src/com/google/refine/io/FileProjectManager.java

@@ -69,15 +69,15 @@ public class FileProjectManager extends ProjectManager {
     final static Logger logger = LoggerFactory.getLogger("FileProjectManager");
 
     static public synchronized void initialize(File dir) {
-        if (singleton == null) {
+        if (singleton != null) {
+            logger.warn("Overwriting singleton already set: " + singleton);
+        }
         logger.info("Using workspace directory: {}", dir.getAbsolutePath());
         singleton = new FileProjectManager(dir);
         // This needs our singleton set, thus the unconventional control flow
         ((FileProjectManager) singleton).recover();
     }
 
-    }
-
     protected FileProjectManager(File dir) {
         super();
         _workspaceDir = dir;