Implemented MSqlConnectionPool for database connection pooling.

diff --git a/4.x/src/java/com/marcozanon/macaco/sql/MSqlConnectionPool.java b/4.x/src/java/com/marcozanon/macaco/sql/MSqlConnectionPool.java
new file mode 100644 (file)
index 0000000..940eaff
--- /dev/null
+++ b/4.x/src/java/com/marcozanon/macaco/sql/MSqlConnectionPool.java
@@ -0,0 +1,89 @@
+/**
+ * Macaco
+ * Copyright (c) 2009-2015 Marco Zanon <info@marcozanon.com>.
+ * Released under MIT license (see LICENSE for details).
+ */
+
+package com.marcozanon.macaco.sql;
+
+import com.marcozanon.macaco.MObject;
+import java.util.LinkedList;
+
+public class MSqlConnectionPool extends MObject {
+
+    protected MSqlConnectionGenerator connectionGenerator = null;
+
+    protected int minimumSize = 0;
+    protected int maximumSize = 0;
+    protected LinkedList<MSqlConnection> connectionPool = new LinkedList<MSqlConnection>();
+
+    /* */
+
+    public MSqlConnectionPool(String driver, String url, String username, String password, int minimumSize, int maximumSize) throws MSqlConnectionFailureException {
+        super();
+        //
+        if (0 > minimumSize) {
+            throw new IllegalArgumentException(String.format("Invalid 'minimumSize': %s.", minimumSize));
+        }
+        if (1 > maximumSize) {
+            throw new IllegalArgumentException(String.format("Invalid 'maximumSize': %s.", maximumSize));
+        }
+        else if (minimumSize > maximumSize) {
+            throw new IllegalArgumentException(String.format("Invalid 'maximumSize': %s < %s ('minimumSize').", maximumSize, minimumSize));
+        }
+        //
+        this.connectionGenerator = new MSqlConnectionGenerator(driver, url, username, password);
+        this.minimumSize = minimumSize;
+        this.maximumSize = maximumSize;
+        //
+        this.initializeConnectionPool();
+    }
+
+    /* Connection generator */
+
+    protected MSqlConnectionGenerator getConnectionGenerator() {
+        return this.connectionGenerator;
+    }
+
+    /* Connection pool */
+
+    protected int getMinimumSize() {
+        return this.minimumSize;
+    }
+
+    protected int getMaximumSize() {
+        return this.maximumSize;
+    }
+
+    protected LinkedList<MSqlConnection> getConnectionPool() {
+        return this.connectionPool;
+    }
+
+    protected void initializeConnectionPool() throws MSqlConnectionFailureException {
+        for (int c = 0; c < this.getMinimumSize(); c++) {
+            MSqlConnection connection = this.getConnectionGenerator().getConnection();
+            this.getConnectionPool().add(connection);
+        }
+    }
+
+    public synchronized MSqlConnection popConnection() throws MSqlConnectionFailureException {
+        LinkedList<MSqlConnection> connectionPool = this.getConnectionPool();
+        MSqlConnection connection = connectionPool.removeLast();
+        if (this.getMinimumSize() > connectionPool.size()) {
+            connectionPool.add(this.getConnectionGenerator().getConnection());
+        }
+        return connection;
+    }
+
+    public synchronized void pushConnection(MSqlConnection connection) {
+        if (null == connection) {
+            throw new IllegalArgumentException("Invalid 'connection': null.");
+        }
+        //
+        LinkedList<MSqlConnection> connectionPool = this.getConnectionPool();
+        if (this.getMaximumSize() >= connectionPool.size()) {
+            connectionPool.add(connection);
+        }
+    }
+
+}