by Dinesh Thakur Category: Servlet with MySql Database

The function 'ASCII'(American standard code for interface and interchange) use to get the numeric value of left most character of a string.

First i made a table in database named 'dbase' with in the reference of mySql(Php myAdmin).I import all the required java packages from java library. After then i declare a class named 'MySqlASCIICode' which extends the 'HttpServlet'. After i use serviceMethod() responsible for the getting request from doGet() method. Then i load all required drivers for database accessing. Then i declare some variables like connection (this will create a bridge between the database and the java code or in other words Frontend and Backend with the help of loaded drivers. The other variable is to declare will be resultset it will use to get the value from required columns and rows into on to the database. The next one will be the preparedStatement the object of the variable is ps. this will be responsible for executing the selected query like executeQuery() as (Select ASCII('mysql')). The next step to use doGet() method which will bring the output on a web browser.

To make output manner able i use 'HTML' tags to get Output in tabular form on a web browser.   

EXAMPLE

 
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySqlASCIICode extends HttpServlet
 {
   public void service(HttpServletRequest rq, HttpServletResponse rp)throws IOException, ServletException
    {
      rp.setContentType("text/html");
      PrintWriter disp = rp.getWriter();
      String driver = "com.mysql.jdbc.Driver";
      String url = "jdbc:mysql://localhost/dbase";
      String uid = "root";
      String psw = "root";
      Connection con=null;
      PreparedStatement ps = null;
      ResultSet rs;
      try
       {
         Class.forName(driver);
         con = DriverManager.getConnection(url,uid,psw);
         ps=con.prepareStatement("Select ASCII('mysql')");
         rs = ps.executeQuery();
             String title = "Using ASCII Function";
         String docType ="<!doctype html public \"-//w3c//dtd html 4.0 " + "transitional//en\">\n";
             disp.println(docType + "<html>\n" + "<head><title>" + title + "</title></head>\n" +
         "<body bgcolor=\"#f4efef\">\n" + "<h1 align=\"center\">" + title + "</h1>\n" + "<ul>\n" +
             "<table width=\"50%\" border=\"1\" align=\"center\">\n" + "<th>Value  </th>\n"+ "</body> </html>");
         while(rs.next())
           {
             String val = rs.getString(1);
                 disp.println("<tr><td align=\"center\">" + val +"</td></tr>" );  
           }     
       }  
                 catch(Exception e) 
                   {
                          e.printStackTrace();
                   }
                          disp.close();
     }
                      public void doPost(HttpServletRequest rq,HttpServletResponse rp)throws IOException,ServletException
                           {
                                 doGet(rq,rp);
                           }
}
 
WEB.XML
 
<servlet>
   <servlet-name>MySqlASCIICode</servlet-name>
   <servlet-class>MySqlASCIICode</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlASCIICode</servlet-name>
   <url-pattern>/MySqlASCIICode</url-pattern>
</servlet-mapping>




About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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