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510

Chapter 18 JDBC and Database Connection Pooling

Listing 18.20 ConnectionPoolServlet.java (continued)

      table = results.toHTMLTable("#FFAD00");

    } catch(Exception e) {

      table = "Error: " + e;

    }

    response.setContentType("text/html");

    // Prevent the browser from caching the response. See

    // Section 7.2 of Core Servlets and JSP for details.

    response.setHeader("Pragma", "no cache"); // HTTP 1.0

    response.setHeader("Cache Control", "no cache"); // HTTP 1.1

    PrintWriter out = response.getWriter();

    String title = "Connection Pool Test";

    out.println(ServletUtilities.headWithTitle(title) +

                "\n" +

                "\n" +

                table + "\n" +

                "\n");

  }

  /** Initialize the connection pool when servlet is

   *  initialized. To avoid a delay on first access, load

   *  the servlet ahead of time yourself or have the

   *  server automatically load it after reboot.

   */

  public void init() {

    int vendor = DriverUtilities.SYBASE;

    String driver = DriverUtilities.getDriver(vendor);

    String host = "dbhost2.apl.jhu.edu";

    String dbName = "605741";

    String url = DriverUtilities.makeURL(host, dbName, vendor);

    String username = "hall";

    String password = "xxxx"; // Changed : )

    try {

      connectionPool =

        new ConnectionPool(driver, url, username, password,

                           initialConnections(),

                           maxConnections(),

                           true);

    } catch(SQLException sqle) {

      System.err.println("Error making pool: " + sqle);

      getServletContext().log("Error making pool: " + sqle);

      connectionPool = null;

    }

  }

  public void destroy() {

    connectionPool.closeAllConnections();

  }

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