by Dinesh Thakur Category: Servlet with MySql Database

The 'BIT_LENGTH' Function will returns the arguments length.

Now i make a table into a database named 'dbase' within the reference of mySql(php myAdmin). I import all the required java packages from java library. Then i make a class named 'MySqlBITLENGTHFunc' which extends the 'Http Servlet'. Then i use serviceMethod() which will use to get the request from doGet() method for Output on web Browser. Then i loaded all the mandatory drivers for database accessing. After that I’ll have to declare the variables like 'connection' (this variable will responsible for the creating a link between database and the java code (actual code). the other variable is 'resultSet' (that will help to fetch value from the selected columns and rows as required).the next will be 'preparedStatement' that will be used to execute the selected query like executeQuery() as (Select BIT_LENGTH('mysql')). The last instance will be to call the doGet()Method that will bring Output on the web browser.

To get Output in a manner form i use 'Html' tags which will appear Output in a tabular form on the 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 MySqlBITLENGTHFunc 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 BIT_LENGTH('mysql')");
       rs = ps.executeQuery();
       String title = "Using BIT LENGTH 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>MySqlBITLENGTHFunc</servlet-name>
   <servlet-class>MySqlBITLENGTHFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlBITLENGTHFunc</servlet-name>
   <url-pattern>/MySqlBITLENGTHFunc</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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