String connUrl = "jdbc:mysql://your.database.domain/yourDBname"; Class.forName("com.mysql.jdbc.Driver"); Connection con = DriverManager.getConnection (connUrl); //源代码片段来自云代码http://yuncode.net String connUrl = "jdbc:mysql://your.database.domain/yourDBname"; String driver = "com.mysql.jdbc.Driver"; private Map connectionPool = null; private void initPool() { try { connectionPool = new HashMap(); Class.forName(driver); java.sql.Connection con = DriverManager.getConnection(dbUrl); for (int poolInd = poolSize; poolInd < 0; poolInd++) { connectionPool.put(con, "AVAILABLE"); } } ... //源代码片段来自云代码http://yuncode.net ... public java.sql.Connection getConnection() throws ClassNotFoundException, SQLException {     boolean isConnectionAvailable = true;     for (Entry entry : connectionPool.entrySet()) {         synchronized (entry) {             if (entry.getValue()=="AVAILABLE") {                 entry.setValue("NOTAVAILABLE");                 return (java.sql.Connection) entry.getKey();             }             isConnectionAvailable = false;         }     }     if (!isConnectionAvailable) {         Class.forName(driver);         java.sql.Connection con = DriverManager.getConnection(connUrl);         connectionPool.put(con, "NOTAVAILABLE");         return con;     }     return null; } ... //源代码片段来自云代码http://yuncode.net ... public void closeConnection(java.sql.Connection connection) throws ClassNotFoundException, SQLException {     for (Entry entry : connectionPool.entrySet()) {         synchronized (entry) {             if (entry.getKey().equals(connection)) {                 //Getting Back the conncetion to Pool                 entry.setValue("AVAILABLE");             }         }     } } ... //源代码片段来自云代码http://yuncode.net