JabRef · koppor · Aug 9, 2016 · May 10, 2016
diff --git a/.gitignore b/.gitignore
@@ -1,6 +1,9 @@
 # no generated files in version control
 src/main/gen/
 
+# do not distribute Oracle's JDBC driver
+lib/ojdbc.jar
+
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err*
 

diff --git a/.travis.yml b/.travis.yml
@@ -26,6 +26,7 @@ install: true
 # allow gui testing on travis
 before_script:
   - psql -c 'create database jabref;' -U postgres
+  - mysql -u root -e 'create database jabref'
 
 script:
   - ./gradlew check

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -12,6 +12,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 ## [Unreleased]
 
 ### Changed
+- [#970](https://github.com/JabRef/jabref/issues/970): Implementation of shared database support (full system) with event based synchronization for MySQL, PostgreSQL and Oracle database systems.
 - Externally fetched information can be merged for entries with an ISBN
 - Externally fetched information can be merged for entries with an ArXiv eprint
 - [#462](https://github.com/JabRef/jabref/issues/462) Extend the OpenConsoleFeature by offering a selection between default terminal emulator and configurable command execution.

diff --git a/src/main/java/net/sf/jabref/BibDatabaseContext.java b/src/main/java/net/sf/jabref/BibDatabaseContext.java
@@ -10,8 +10,10 @@
 import net.sf.jabref.model.database.BibDatabase;
 import net.sf.jabref.model.database.BibDatabaseMode;
 import net.sf.jabref.model.database.BibDatabaseModeDetection;
+import net.sf.jabref.model.database.DatabaseLocation;
 import net.sf.jabref.model.entry.FieldName;
 import net.sf.jabref.preferences.JabRefPreferences;
+import net.sf.jabref.shared.DBMSSynchronizer;
 
 /**
  * Represents everything related to a BIB file.
@@ -25,6 +27,8 @@ public class BibDatabaseContext {
     private final Defaults defaults;
     /** The file where this database was last saved to. */
     private File file;
+    private DBMSSynchronizer dbmsSynchronizer;
+    private DatabaseLocation location;
 
     public BibDatabaseContext() {
         this(new Defaults());
@@ -43,9 +47,15 @@ public BibDatabaseContext(BibDatabase database, Defaults defaults) {
     }
 
     public BibDatabaseContext(BibDatabase database, MetaData metaData, Defaults defaults) {
+        this(database, metaData, defaults, DatabaseLocation.LOCAL);
+    }
+
+    public BibDatabaseContext(BibDatabase database, MetaData metaData, Defaults defaults, DatabaseLocation location) {
         this.defaults = Objects.requireNonNull(defaults);
         this.database = Objects.requireNonNull(database);
         this.metaData = Objects.requireNonNull(metaData);
+
+        updateDatabaseLocation(location);
     }
 
     public BibDatabaseContext(BibDatabase database, MetaData metaData) {
@@ -62,6 +72,10 @@ public BibDatabaseContext(BibDatabase database, MetaData metaData, File file) {
         this(database, metaData, file, new Defaults());
     }
 
+    public BibDatabaseContext(Defaults defaults, DatabaseLocation location) {
+        this(new BibDatabase(), new MetaData(), defaults, location);
+    }
+
     public BibDatabaseMode getMode() {
         Optional<BibDatabaseMode> mode = metaData.getMode();
 
@@ -181,4 +195,28 @@ private String getFileDirectoryPath(String directoryName) {
     public List<String> getFileDirectory() {
         return getFileDirectory(FieldName.FILE);
     }
+
+    public DBMSSynchronizer getDBSynchronizer() {
+        return this.dbmsSynchronizer;
+    }
+
+    public DatabaseLocation getLocation() {
+        return this.location;
+    }
+
+    public void updateDatabaseLocation(DatabaseLocation newLocation) {
+
+        if ((this.location == DatabaseLocation.SHARED) && (newLocation == DatabaseLocation.LOCAL)) {
+            this.database.unregisterListener(dbmsSynchronizer);
+            this.metaData.unregisterListener(dbmsSynchronizer);
+        }
+
+        if (newLocation == DatabaseLocation.SHARED) {
+            this.dbmsSynchronizer = new DBMSSynchronizer(this);
+            this.database.registerListener(dbmsSynchronizer);
+            this.metaData.registerListener(dbmsSynchronizer);
+        }
+
+        this.location = newLocation;
+    }
 }
diff --git a/src/main/java/net/sf/jabref/MetaData.java b/src/main/java/net/sf/jabref/MetaData.java
@@ -31,6 +31,8 @@
 import java.util.TreeMap;
 import java.util.Vector;
 
+import net.sf.jabref.event.GroupUpdatedEvent;
+import net.sf.jabref.event.MetaDataChangedEvent;
 import net.sf.jabref.importer.fileformat.ParseException;
 import net.sf.jabref.logic.config.SaveOrderConfig;
 import net.sf.jabref.logic.exporter.FieldFormatterCleanups;
@@ -43,8 +45,8 @@
 import net.sf.jabref.logic.util.strings.StringUtil;
 import net.sf.jabref.model.database.BibDatabaseMode;
 import net.sf.jabref.model.entry.FieldName;
-import net.sf.jabref.sql.DBStrings;
 
+import com.google.common.eventbus.EventBus;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -66,14 +68,12 @@ public class MetaData implements Iterable<String> {
 
     private final Map<String, List<String>> metaData = new HashMap<>();
     private GroupTreeNode groupsRoot;
+    private final EventBus eventBus = new EventBus();
 
     private AbstractLabelPattern labelPattern;
 
-    private DBStrings dbStrings = new DBStrings();
-
     private Charset encoding = Globals.prefs.getDefaultEncoding();
 
-
     /**
      * The MetaData object stores all meta data sets in Vectors. To ensure that
      * the data is written correctly to string, the user of a meta data Vector
@@ -82,7 +82,22 @@ public class MetaData implements Iterable<String> {
      */
     private MetaData(Map<String, String> inData) throws ParseException {
         Objects.requireNonNull(inData);
+        setData(inData);
+    }
 
+    /**
+     * The MetaData object can be constructed with no data in it.
+     */
+    public MetaData() {
+        // No data
+    }
+
+    public static MetaData parse(Map<String, String> data) throws ParseException {
+        return new MetaData(data);
+    }
+
+    public void setData(Map<String, String> inData) throws ParseException {
+        clearMetaData();
         for (Map.Entry<String, String> entry : inData.entrySet()) {
             StringReader data = new StringReader(entry.getValue());
             List<String> orderedData = new ArrayList<>();
@@ -98,25 +113,15 @@ private MetaData(Map<String, String> inData) throws ParseException {
             if (GROUPSTREE.equals(entry.getKey())) {
                 putGroups(orderedData);
                 // the keys "groupsversion" and "groups" were used in JabRef versions around 1.3, we will not support them anymore
+                eventBus.post(new GroupUpdatedEvent(this));
             } else if (SAVE_ACTIONS.equals(entry.getKey())) {
-                setSaveActions(FieldFormatterCleanups.parse(orderedData));
+                metaData.put(SAVE_ACTIONS, FieldFormatterCleanups.parse(orderedData).getAsStringList()); // Without MetaDataChangedEvent
             } else {
-                putData(entry.getKey(), orderedData);
+                metaData.put(entry.getKey(), orderedData);
             }
         }
     }
 
-    /**
-     * The MetaData object can be constructed with no data in it.
-     */
-    public MetaData() {
-        // No data
-    }
-
-    public static MetaData parse(Map<String, String> data) throws ParseException {
-        return new MetaData(data);
-    }
-
     public Optional<SaveOrderConfig> getSaveOrderConfig() {
         List<String> storedSaveOrderConfig = getData(SAVE_ORDER_CONFIG);
         if (storedSaveOrderConfig != null) {
@@ -161,7 +166,10 @@ public List<String> getData(String key) {
      * @param key the key to remove
      */
     public void remove(String key) {
-        metaData.remove(key);
+        if (metaData.containsKey(key)) { //otherwise redundant and disturbing events are going to be posted
+            metaData.remove(key);
+            postChange();
+        }
     }
 
     /**
@@ -172,6 +180,7 @@ public void remove(String key) {
      */
     public void putData(String key, List<String> orderedData) {
         metaData.put(key, orderedData);
+        postChange();
     }
 
     /**
@@ -182,6 +191,7 @@ public void putData(String key, List<String> orderedData) {
     private void putGroups(List<String> orderedData) throws ParseException {
         try {
             groupsRoot = GroupTreeNode.parse(orderedData, Globals.prefs);
+            eventBus.post(new GroupUpdatedEvent(this));
         } catch (ParseException e) {
             throw new ParseException(Localization.lang(
                     "Group tree could not be parsed. If you save the BibTeX database, all groups will be lost."), e);
@@ -198,6 +208,7 @@ public GroupTreeNode getGroups() {
      */
     public void setGroups(GroupTreeNode root) {
         groupsRoot = root;
+        eventBus.post(new GroupUpdatedEvent(this));
     }
 
     /**
@@ -225,14 +236,6 @@ private static Optional<String> getNextUnit(Reader reader) throws IOException {
         return Optional.empty();
     }
 
-    public DBStrings getDBStrings() {
-        return dbStrings;
-    }
-
-    public void setDBStrings(DBStrings dbStrings) {
-        this.dbStrings = dbStrings;
-    }
-
     /**
      * @return the stored label patterns
      */
@@ -390,7 +393,6 @@ public Map<String, String> getAsStringMap() {
             }
             serializedMetaData.put(GROUPSTREE, stringBuilder.toString());
         }
-
         return serializedMetaData;
     }
 
@@ -448,6 +450,13 @@ public void clearSaveOrderConfig() {
         remove(SAVE_ORDER_CONFIG);
     }
 
+    /**
+     * Posts a new {@link MetaDataChangedEvent} on the {@link EventBus}.
+     */
+    public void postChange() {
+        eventBus.post(new MetaDataChangedEvent(this));
+    }
+
     /**
      * Returns the encoding used during parsing.
      */
@@ -458,4 +467,16 @@ public Charset getEncoding() {
     public void setEncoding(Charset encoding) {
         this.encoding = Objects.requireNonNull(encoding);
     }
+
+    public void clearMetaData() {
+        metaData.clear();
+    }
+
+    public void registerListener(Object listener) {
+        this.eventBus.register(listener);
+    }
+
+    public void unregisterListener(Object listener) {
+        this.eventBus.unregister(listener);
+    }
 }
diff --git a/src/main/java/net/sf/jabref/event/GroupUpdatedEvent.java b/src/main/java/net/sf/jabref/event/GroupUpdatedEvent.java
@@ -0,0 +1,19 @@
+package net.sf.jabref.event;
+
+import net.sf.jabref.MetaData;
+
+public class GroupUpdatedEvent {
+
+    private final MetaData metaData;
+
+    /**
+     * @param metaData Affected instance
+     */
+    public GroupUpdatedEvent(MetaData metaData) {
+        this.metaData = metaData;
+    }
+
+    public MetaData getMetaData() {
+        return this.metaData;
+    }
+}
diff --git a/src/main/java/net/sf/jabref/event/MetaDataChangedEvent.java b/src/main/java/net/sf/jabref/event/MetaDataChangedEvent.java
@@ -0,0 +1,22 @@
+package net.sf.jabref.event;
+
+import net.sf.jabref.MetaData;
+
+/**
+ * {@link MetaDataChangedEvent} is fired when a tuple of meta data has been put or removed.
+ */
+public class MetaDataChangedEvent {
+
+    private final MetaData metaData;
+
+    /**
+     * @param metaData Affected instance
+     */
+    public MetaDataChangedEvent(MetaData metaData) {
+        this.metaData = metaData;
+    }
+
+    public MetaData getMetaData() {
+        return this.metaData;
+    }
+}
diff --git a/src/main/java/net/sf/jabref/event/source/EntryEventSource.java b/src/main/java/net/sf/jabref/event/source/EntryEventSource.java
@@ -0,0 +1,26 @@
+/*  Copyright (C) 2016 JabRef contributors.
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+package net.sf.jabref.event.source;
+
+/**
+ * This enum represents the context EntryEvents were sent from.
+ */
+public enum EntryEventSource {
+    LOCAL,
+    SHARED,
+    UNDO,
+    SAVE_ACTION
+}