1 files changed, 156 insertions, 0 deletions
diff --git a/java/demo/Database/library/ConnectionPool.java b/java/demo/Database/library/ConnectionPool.java
new file mode 100644
index 00000000000..852f6388115
--- /dev/null
+++ b/java/demo/Database/library/ConnectionPool.java
@@ -0,0 +1,156 @@
+// **********************************************************************
+//
+// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
+//
+// This copy of Ice is licensed to you under the terms described in the
+// ICE_LICENSE file included in this distribution.
+//
+// **********************************************************************
+
+class ConnectionPool
+{
+    public synchronized void
+    destroy()
+    {
+        _destroyed = true;
+        while(_connections.size() != _nconnections)
+        {
+            try
+            {
+                wait();
+            }
+            catch(InterruptedException e)
+            {
+            }
+        }
+
+        while(!_connections.isEmpty())
+        {
+            java.sql.Connection conn = _connections.removeFirst();
+            try
+            {
+                conn.close();
+            }
+            catch(java.sql.SQLException e)
+            {
+            }
+        }
+    }
+
+    public synchronized java.sql.Connection
+    acquire()
+    {
+        while(_connections.isEmpty() && !_destroyed)
+        {
+            try
+            {
+                wait();
+            }
+            catch(InterruptedException e)
+            {
+            }
+        }
+        if(_destroyed)
+        {
+            return null;
+        }
+        java.sql.Connection conn = _connections.removeFirst();
+
+        try
+        {
+            boolean closed = conn.isClosed();
+            if(closed)
+            {
+                _logger.warning("ConnectionPool: lost connection to database");
+                conn = null;
+            }
+            else
+            {
+                // Probe the connection with the database.
+                java.sql.PreparedStatement stmt = conn.prepareStatement("SELECT 1");
+                java.sql.ResultSet rs = stmt.executeQuery();
+                stmt.close();
+            }
+        }
+        catch(java.sql.SQLException e)
+        {
+            java.io.StringWriter sw = new java.io.StringWriter();
+            java.io.PrintWriter pw = new java.io.PrintWriter(sw);
+            e.printStackTrace(pw);
+            pw.flush();
+            _logger.warning("ConnectionPool: lost connection to database:\n" + sw.toString());
+
+            conn = null;
+        }
+
+        // If the connection has been closed, or is otherwise invalid,
+        // we need to re-establish the connection.
+        while(conn == null)
+        {
+            if(_trace)
+            {
+                _logger.trace("ConnectionPool", "establishing new database connection");
+            }
+            try
+            {
+                conn = java.sql.DriverManager.getConnection(_url, _username, _password);
+                conn.setAutoCommit(false);
+            }
+            catch(java.sql.SQLException e)
+            {
+                java.io.StringWriter sw = new java.io.StringWriter();
+                java.io.PrintWriter pw = new java.io.PrintWriter(sw);
+                e.printStackTrace(pw);
+                pw.flush();
+                _logger.warning("ConnectionPool: database connection failed:\n" + sw.toString());
+            }
+        }
+        if(_trace)
+        {
+            _logger.trace("ConnectionPool", "returning connection: " + conn + " " +
+                          _connections.size() + "/" + _nconnections + " remaining");
+        }
+        return conn;
+    }
+
+    public synchronized void
+    release(java.sql.Connection connection)
+    {
+        if(connection != null)
+        {
+            _connections.add(connection);
+            notifyAll();
+        }
+    }
+
+    ConnectionPool(Ice.Logger logger, String url, String username, String password, int numConnections)
+        throws java.sql.SQLException
+    {
+        _logger = logger;
+        _url = url;
+        _username = username;
+        _password = password;
+
+        _nconnections = numConnections;
+        if(_trace)
+        {
+            _logger.trace("ConnectionPool", "establishing " + numConnections + " connections to " + url);
+        }
+        while(numConnections-- > 0)
+        {
+            java.sql.Connection connection = java.sql.DriverManager.getConnection(url, username, password);
+            connection.setAutoCommit(false);
+            _connections.add(connection);
+        }
+    }
+
+
+    private Ice.Logger _logger;
+    private boolean _trace = true;
+    private String _url;
+    private String _username;
+    private String _password;
+    private java.util.LinkedList<java.sql.Connection> _connections = new java.util.LinkedList<java.sql.Connection>();
+    private boolean _destroyed = false;
+    private int _nconnections;
+}