package com.wrox.tourism.db.util;import java.sql.SQLException;import java.sql.Connection;import javax.sql.DataSource;public class ConnectionPool {  private DataSource ds;  private static ConnectionPool mySelf;  private ConnectionPool(DataSource ds) {    this.ds = ds;  }  public static void init(DataSource ds) {    mySelf = new ConnectionPool(ds);  }  public static ConnectionPool getInstance() {    if (mySelf == null) {      throw new IllegalStateException("Pool not initialized.");    }    return mySelf;  }  public Connection getConnection() throws SQLException {    return ds.getConnection();  }}