Servlet Update Database : Database « Servlet « Java Tutorial





import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class MyServlet extends HttpServlet {

  public void doPost(HttpServletRequest req, HttpServletResponse res)
                                throws ServletException, IOException {
    res.setContentType("text/plain");
    PrintWriter out = res.getWriter();

    Connection con = null;
    try {
      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
      con = DriverManager.getConnection("jdbc:odbc:ordersdb", "user", "passwd");

      // Turn on transactions
      con.setAutoCommit(false);

      Statement stmt = con.createStatement();
      stmt.executeUpdate("UPDATE INVENTORY SET STOCK = (STOCK - 10) ");
      stmt.executeUpdate("UPDATE SHIPPING SET SHIPPED = (SHIPPED + 10)");

      con.commit();
      out.println("Order successful!  Thanks for your business!");
    }
    catch (Exception e) {
      // Any error is grounds for rollback
      try {
        con.rollback();
      }
      catch (SQLException ignored) { }
      out.println("Order failed. Please contact technical support.");
    }
    finally {
      // Clean up.
      try {
        if (con != null) con.close();
      }
      catch (SQLException ignored) { }
    }
  }
}
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>

    <servlet><servlet-name>MyServletName</servlet-name>
             <servlet-class>MyServlet</servlet-class>
    </servlet>
    
    <servlet-mapping><servlet-name>MyServletName</servlet-name>
        <url-pattern>*.htm</url-pattern>
    </servlet-mapping>

  <context-param>
    <param-name>javax.servlet.jsp.jstl.fmt.timeZone</param-name>
    <param-value>US/Central</param-value>
  </context-param>

  <context-param>
    <param-name>database-driver</param-name>
    <param-value>org.gjt.mm.mysql.Driver</param-value>
  </context-param>

  <context-param>
    <param-name>database-url</param-name>
    <param-value>
    jdbc:mysql://localhost/forum?user=forumuser</param-value>
  </context-param>
</web-app>
  Download:  ServletUpdateDatabase.zip( 1,067 k)










25.33.Database
25.33.1.Servlet Database Connection
25.33.2.Servlet Update Database
25.33.3.Servlet Database ResultSet Display Helper
25.33.4.Servlet Database Gif Decoder
25.33.5.Returns the list of the most popular flavors
25.33.6.Read data from Database and display it in a HTML table