by Dinesh Thakur Category: Servlet with MySql Database

This function is been used to Check Pattern with regular expressions.

In the first instance of programming i made a database named 'dbase' that within the reference of mySql(php myAdmin).Then i import all the required java packages from java library. Then i made a class named 'MySqlREGEXPFunction' extends 'HttpServlet'. I use here service()Method that will getting the request from doGet()Method for output on the web browser. I loaded all the required drivers for database accessing. Here i use variables for database link I use 'connection' this will create a link a between database and the java code. I use 'resultSet' this will use to get the value from the selected columns and the rows. Then i use 'preparedStatement' that will use to executing the query like executeQuery as (SELECT 'Mysql!' REGEXP '.*')). I use here doGet()Method for output on the web browser.

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

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 MySqlREGEXPFunction 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 'Mysql!' REGEXP '.*'");
                rs = ps.executeQuery();
            String title = "Using Regular Expression 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 Is </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>MySqlREGEXPFunction</servlet-name>
   <servlet-class>MySqlREGEXPFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlREGEXPFunction</servlet-name>
   <url-pattern>/MySqlREGEXPFunction</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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