A connection provider that obtains connections from a DataSource, which

supports pooling.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@2477 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/jdbc/DataSourceConnectionProvider.java

@@ -0,0 +1,110 @@
+//
+// $Id$
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001-2008 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;
+import javax.sql.DataSource;
+
+import com.samskivert.io.PersistenceException;
+
+import static com.samskivert.Log.log;
+
+/**
+ * Provides connections using a pair of {@link DataSource} instances (one for read-only operations
+ * and one for read-write operations).
+ */
+public class DataSourceConnectionProvider implements ConnectionProvider
+{
+    /**
+     * Creates a connection provider that will obtain connections from the supplied read-only and
+     * read-write sources. The <code>ident</code> mechanism is not used by this provider.
+     * Responsibility for the lifecycle of the supplied datasources is left to the caller and is
+     * not managed by the connection provider ({@link #shutdown} does nothing).
+     *
+     * @param url a URL prefix that can be used by the {@link DatabaseLiaison} to identify the type
+     * of database being accessed by the supplied data sources, this should be one of "jdbc:mysql"
+     * or "jdbc:postgresql" as those are the only two types of database currently supported.
+     */
+    public DataSourceConnectionProvider (String url, DataSource readSource, DataSource writeSource)
+    {
+        _url = url;
+        _readSource = readSource;
+        _writeSource = writeSource;
+    }
+
+    // from interface ConnectionProvider
+    public Connection getConnection (String ident, boolean readOnly)
+        throws PersistenceException
+    {
+        try {
+            Connection conn;
+            if (readOnly) {
+                conn = _readSource.getConnection();
+                conn.setReadOnly(true);
+            } else {
+                conn = _writeSource.getConnection();
+            }
+            return conn;
+
+        } catch (SQLException sqe) {
+            throw new PersistenceException(sqe);
+        }
+    }
+
+    // from interface ConnectionProvider
+    public void releaseConnection (String ident, boolean readOnly, Connection conn)
+    {
+        try {
+            conn.close();
+        } catch (Exception e) {
+            log.warning("Failure closing connection",
+                        "ident", ident, "ro", readOnly, "conn", conn, e);
+        }
+    }
+
+    // from interface ConnectionProvider
+    public void connectionFailed (String ident, boolean readOnly, Connection conn,
+                                  SQLException error)
+    {
+        try {
+            conn.close();
+        } catch (Exception e) {
+            log.warning("Failure closing failed connection",
+                        "ident", ident, "ro", readOnly, "conn", conn, e);
+        }
+    }
+
+    // from interface ConnectionProvider
+    public String getURL (String ident)
+    {
+        return _url;
+    }
+
+    // from interface ConnectionProvider
+    public void shutdown ()
+    {
+        // nothing doing, the caller has to shutdown the datasources
+    }
+
+    protected String _url;
+    protected DataSource _readSource, _writeSource;
+}