Finished up liaison stuff.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@324 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/jdbc/DatabaseLiaison.java

@@ -1,5 +1,5 @@
 //
-// $Id: DatabaseLiaison.java,v 1.1 2001/09/20 01:53:19 mdb Exp $
+// $Id: DatabaseLiaison.java,v 1.2 2001/09/20 02:09:09 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -33,12 +33,13 @@ import java.sql.SQLException;
 public interface DatabaseLiaison
 {
     /**
-     * Indicates whether this particular RDBMS/JDBC driver combination
+     * Indicates whether or not this database liaison is the proper
-     * supports transactions.
+     * liaison for the specified database URL.
      *
-     * @return true if transactions are supported, false if not.
+     * @return true if we should use this liaison for connections created
+     * with the supplied URL, false if we should not.
      */
-    public boolean supportsTransactions ();
+    public boolean matchesURL (String url);
 
     /**
      * Determines whether or not the supplied SQL exception was caused by

projects/samskivert/src/java/com/samskivert/jdbc/DefaultLiaison.java

@@ -0,0 +1,56 @@
+//
+// $Id: DefaultLiaison.java,v 1.1 2001/09/20 02:09:09 mdb Exp $
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001 Michael Bayne
+// 
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.jdbc;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+/**
+ * The default liaison is used if no other liaison could be matched for a
+ * particular database connection. It isn't very smart or useful but we
+ * need something.
+ */
+public class DefaultLiaison implements DatabaseLiaison
+{
+    // documentation inherited
+    public boolean matchesURL (String url)
+    {
+        return true;
+    }
+
+    // documentation inherited
+    public boolean isDuplicateRowException (SQLException sqe)
+    {
+        return false;
+    }
+
+    // documentation inherited
+    public boolean isTransientException (SQLException sqe)
+    {
+        return false;
+    }
+
+    // documentation inherited
+    public int lastInsertedId (Connection conn) throws SQLException
+    {
+        return -1;
+    }
+}

projects/samskivert/src/java/com/samskivert/jdbc/LiaisonRegistry.java

@@ -1,5 +1,5 @@
 //
-// $Id: LiaisonRegistry.java,v 1.1 2001/09/20 01:53:19 mdb Exp $
+// $Id: LiaisonRegistry.java,v 1.2 2001/09/20 02:09:09 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -22,6 +22,12 @@ package com.samskivert.jdbc;
 
 import java.sql.*;
 
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.HashMap;
+
+import com.samskivert.Log;
+
 /**
  * The liaison registry provides access to the appropriate database
  * liaison implementation for a particular database connection.
@@ -33,7 +39,48 @@ public class LiaisonRegistry
      * connection.
      */
     public static DatabaseLiaison getLiaison (Connection conn)
+        throws SQLException
     {
-        return null;
+        DatabaseMetaData dmd = conn.getMetaData();
+        String url = dmd.getURL();
+
+        // see if we already have a liaison mapped for this connection
+        DatabaseLiaison liaison = (DatabaseLiaison)_mappings.get(url);
+
+        if (liaison == null) {
+            // scan the list looking for a matching liaison
+            Iterator iter = _liaisons.iterator();
+            while (iter.hasNext()) {
+                DatabaseLiaison candidate = (DatabaseLiaison)iter.next();
+                if (candidate.matchesURL(url)) {
+                    liaison = candidate;
+                    break;
+                }
+            }
+
+            // if we didn't find a matching liaison, use the default
+            if (liaison == null) {
+                liaison = new DefaultLiaison();
+            }
+
+            // map this URL to this liaison
+            _mappings.put(url, liaison);
+        }
+
+        return liaison;
     }
+
+    protected static void registerLiaisonClass (Class lclass)
+    {
+        // create a new instance and stick it on our list
+        try {
+            _liaisons.add(lclass.newInstance());
+        } catch (Exception e) {
+            Log.warning("Unable to instantiate liaison " +
+                        "[class=" + lclass.getName() + ", error=" + e + "].");
+        }
+    }
+
+    protected static ArrayList _liaisons = new ArrayList();
+    protected static HashMap _mappings = new HashMap();
 }

projects/samskivert/src/java/com/samskivert/jdbc/MySQLLiaison.java

@@ -1,5 +1,5 @@
 //
-// $Id: MySQLLiaison.java,v 1.1 2001/09/20 01:53:19 mdb Exp $
+// $Id: MySQLLiaison.java,v 1.2 2001/09/20 02:09:09 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -28,9 +28,9 @@ import java.sql.*;
 public class MySQLLiaison
 {
     // documentation inherited
-    public boolean supportsTransactions ()
+    public boolean matchesURL (String url)
     {
-        return false;
+        return url.startsWith("jdbc:mysql");
     }
 
     // documentation inherited

projects/samskivert/src/java/com/samskivert/jdbc/SimpleRepository.java

@@ -1,5 +1,5 @@
 //
-// $Id: SimpleRepository.java,v 1.1 2001/09/20 01:53:20 mdb Exp $
+// $Id: SimpleRepository.java,v 1.2 2001/09/20 02:09:09 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -77,19 +77,22 @@ public class SimpleRepository extends Repository
     protected Object execute (Operation op, boolean retryOnTransientFailure)
 	throws PersistenceException
     {
-        // obtain our database connection
         Connection conn = null;
+        DatabaseMetaData dmd = null;
+        DatabaseLiaison liaison = null;
+
+        // obtain our database connection and associated goodies
         try {
             conn = _provider.getConnection(_dbident);
             conn.setAutoCommit(false);
+            dmd = conn.getMetaData();
+            liaison = LiaisonRegistry.getLiaison(conn);
             gotConnection(conn);
         } catch (SQLException sqe) {
             String err = "Unable to obtain connection.";
             throw new PersistenceException(err, sqe);
         }
 
-        // obtain a liaison for this connection
-        DatabaseLiaison liaison = LiaisonRegistry.getLiaison(conn);
         Object rv = null;
 
         try {
@@ -97,7 +100,7 @@ public class SimpleRepository extends Repository
 	    rv = op.invoke(conn, liaison);
 
 	    // commit the transaction
-            if (liaison.supportsTransactions()) {
+            if (dmd.supportsTransactions()) {
                 conn.commit();
             }
 
@@ -106,13 +109,13 @@ public class SimpleRepository extends Repository
 
 	} catch (SQLException sqe) {
 	    // back out our changes if something got hosed
-            if (liaison.supportsTransactions()) {
+            try {
-                try {
+                if (dmd.supportsTransactions()) {
                     conn.rollback();
-                } catch (SQLException rbe) {
-                    Log.warning("Unable to roll back operation.");
-                    Log.logStackTrace(rbe);
                 }
+            } catch (SQLException rbe) {
+                Log.warning("Unable to roll back operation.");
+                Log.logStackTrace(rbe);
             }
 
             // let the connection provider know that the connection failed
@@ -134,25 +137,25 @@ public class SimpleRepository extends Repository
 
 	} catch (PersistenceException pe) {
 	    // back out our changes if something got hosed
-            if (liaison.supportsTransactions()) {
+            try {
-                try {
+                if (dmd.supportsTransactions()) {
                     conn.rollback();
-                } catch (SQLException rbe) {
-                    Log.warning("Unable to roll back operation.");
-                    Log.logStackTrace(rbe);
                 }
+            } catch (SQLException rbe) {
+                Log.warning("Unable to roll back operation.");
+                Log.logStackTrace(rbe);
             }
             throw pe;
 
 	} catch (RuntimeException rte) {
 	    // back out our changes if something got hosed
-            if (conn != null && liaison.supportsTransactions()) {
+            try {
-                try {
+                if (conn != null && dmd.supportsTransactions()) {
                     conn.rollback();
-                } catch (SQLException rbe) {
-                    Log.warning("Unable to roll back operation.");
-                    Log.logStackTrace(rbe);
                 }
+            } catch (SQLException rbe) {
+                Log.warning("Unable to roll back operation.");
+                Log.logStackTrace(rbe);
             }
 	    throw rte;