New sample application: CachedPreparedStatements.

h2/src/test/org/h2/samples/CachedPreparedStatements.java

+/*
+ * Copyright 2004-2010 H2 Group. Multiple-Licensed under the H2 License,
+ * Version 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.samples;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * This sample application shows how to cache prepared statements.
+ */
+public class CachedPreparedStatements {
+
+    private Connection conn;
+    private Statement stat;
+    private Map<String, PreparedStatement> prepared = 
+        Collections.synchronizedMap(
+                new HashMap<String, PreparedStatement>());
+    
+    /**
+     * This method is called when executing this sample application from the
+     * command line.
+     *
+     * @param args the command line parameters
+     */
+    public static void main(String... args) throws Exception {
+        new CachedPreparedStatements().run();
+    }
+
+    private void run() throws Exception {
+        Class.forName("org.h2.Driver");
+        conn = DriverManager.getConnection(
+                "jdbc:h2:mem:", "sa", "");
+        stat = conn.createStatement();
+        stat.execute(
+                "create table test(id int primary key, name varchar)");
+        PreparedStatement prep = prepare(
+                "insert into test values(?, ?)");
+        prep.setInt(1, 1);
+        prep.setString(2, "Hello");
+        prep.execute();
+        conn.close();    
+    }
+
+    private PreparedStatement prepare(String sql) 
+            throws SQLException {
+        PreparedStatement prep = prepared.get(sql);
+        if (prep == null) {
+            prep = conn.prepareStatement(sql);
+            prepared.put(sql, prep);
+        }
+        return prep;
+    }
+
+}