1 files changed, 168 insertions, 0 deletions
diff --git a/server/src/com/vaadin/data/util/sqlcontainer/connection/SimpleJDBCConnectionPool.java b/server/src/com/vaadin/data/util/sqlcontainer/connection/SimpleJDBCConnectionPool.java
new file mode 100644
index 0000000000..21760014b9
--- /dev/null
+++ b/server/src/com/vaadin/data/util/sqlcontainer/connection/SimpleJDBCConnectionPool.java
@@ -0,0 +1,168 @@
+/*
+@VaadinApache2LicenseForJavaFiles@
+ */
+package com.vaadin.data.util.sqlcontainer.connection;
+
+import java.io.IOException;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Simple implementation of the JDBCConnectionPool interface. Handles loading
+ * the JDBC driver, setting up the connections and ensuring they are still
+ * usable upon release.
+ */
+@SuppressWarnings("serial")
+public class SimpleJDBCConnectionPool implements JDBCConnectionPool {
+
+    private int initialConnections = 5;
+    private int maxConnections = 20;
+
+    private String driverName;
+    private String connectionUri;
+    private String userName;
+    private String password;
+
+    private transient Set<Connection> availableConnections;
+    private transient Set<Connection> reservedConnections;
+
+    private boolean initialized;
+
+    public SimpleJDBCConnectionPool(String driverName, String connectionUri,
+            String userName, String password) throws SQLException {
+        if (driverName == null) {
+            throw new IllegalArgumentException(
+                    "JDBC driver class name must be given.");
+        }
+        if (connectionUri == null) {
+            throw new IllegalArgumentException(
+                    "Database connection URI must be given.");
+        }
+        if (userName == null) {
+            throw new IllegalArgumentException(
+                    "Database username must be given.");
+        }
+        if (password == null) {
+            throw new IllegalArgumentException(
+                    "Database password must be given.");
+        }
+        this.driverName = driverName;
+        this.connectionUri = connectionUri;
+        this.userName = userName;
+        this.password = password;
+
+        /* Initialize JDBC driver */
+        try {
+            Class.forName(driverName).newInstance();
+        } catch (Exception ex) {
+            throw new RuntimeException("Specified JDBC Driver: " + driverName
+                    + " - initialization failed.", ex);
+        }
+    }
+
+    public SimpleJDBCConnectionPool(String driverName, String connectionUri,
+            String userName, String password, int initialConnections,
+            int maxConnections) throws SQLException {
+        this(driverName, connectionUri, userName, password);
+        this.initialConnections = initialConnections;
+        this.maxConnections = maxConnections;
+    }
+
+    private void initializeConnections() throws SQLException {
+        availableConnections = new HashSet<Connection>(initialConnections);
+        reservedConnections = new HashSet<Connection>(initialConnections);
+        for (int i = 0; i < initialConnections; i++) {
+            availableConnections.add(createConnection());
+        }
+        initialized = true;
+    }
+
+    @Override
+    public synchronized Connection reserveConnection() throws SQLException {
+        if (!initialized) {
+            initializeConnections();
+        }
+        if (availableConnections.isEmpty()) {
+            if (reservedConnections.size() < maxConnections) {
+                availableConnections.add(createConnection());
+            } else {
+                throw new SQLException("Connection limit has been reached.");
+            }
+        }
+
+        Connection c = availableConnections.iterator().next();
+        availableConnections.remove(c);
+        reservedConnections.add(c);
+
+        return c;
+    }
+
+    @Override
+    public synchronized void releaseConnection(Connection conn) {
+        if (conn == null || !initialized) {
+            return;
+        }
+        /* Try to roll back if necessary */
+        try {
+            if (!conn.getAutoCommit()) {
+                conn.rollback();
+            }
+        } catch (SQLException e) {
+            /* Roll back failed, close and discard connection */
+            try {
+                conn.close();
+            } catch (SQLException e1) {
+                /* Nothing needs to be done */
+            }
+            reservedConnections.remove(conn);
+            return;
+        }
+        reservedConnections.remove(conn);
+        availableConnections.add(conn);
+    }
+
+    private Connection createConnection() throws SQLException {
+        Connection c = DriverManager.getConnection(connectionUri, userName,
+                password);
+        c.setAutoCommit(false);
+        if (driverName.toLowerCase().contains("mysql")) {
+            try {
+                Statement s = c.createStatement();
+                s.execute("SET SESSION sql_mode = 'ANSI'");
+                s.close();
+            } catch (Exception e) {
+                // Failed to set ansi mode; continue
+            }
+        }
+        return c;
+    }
+
+    @Override
+    public void destroy() {
+        for (Connection c : availableConnections) {
+            try {
+                c.close();
+            } catch (SQLException e) {
+                // No need to do anything
+            }
+        }
+        for (Connection c : reservedConnections) {
+            try {
+                c.close();
+            } catch (SQLException e) {
+                // No need to do anything
+            }
+        }
+
+    }
+
+    private void writeObject(java.io.ObjectOutputStream out) throws IOException {
+        initialized = false;
+        out.defaultWriteObject();
+    }
+
+}