This Function Will Return the substring as specified.
First i use to make a database named ‘dbase’ within the reference of mySql(php myAdmin). Then i use to import all required java package from java library. Then after calling all the packages, i made a class named ‘MySqlSUBSTRINGFunction’, which extends ‘HttpServlet’. I use service()Method which will use to getting the request from doGet()Method for output. Then i loaded all the required drivers for database accessing. After loading driver, I declare the variables as i use ‘connection’ variable that will use to create a link between the database and the java code. Then after, I use ‘resultSet’ that will act as to fetching value from the selected column and rows. I use ‘preparedStatement’ that will use to executing the selected query like executeQuery as (Select SUBSTRING (‘servletmysql’,5)). I use doGet()Method in last interface which will use to get output on the web browser.
I use here some tags of ‘HTML’ that will bring output in a tabular form as required.
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 MySqlSUBSTRINGFunction 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 SUBSTRING('servletmysql',5)"); rs = ps.executeQuery(); String title = "Using SUBSTRING 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>MySqlSUBSTRINGFunction</servlet-name> <servlet-class>MySqlSUBSTRINGFunction</servlet-class> </servlet> <!-- servlet mapping --> <servlet-mapping> <servlet-name>MySqlSUBSTRINGFunction</servlet-name> <url-pattern>/MySqlSUBSTRINGFunction</url-pattern> </servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular