The Expressions in Parenthesis (Brackets) will be executed.
I made a table named ‘worker’ into database named ‘dbase’ within the reference of mySql(php myAdmin). Then i import all the required packages from java library. Then i made a class named ‘MySqlParanthesesJavaServlet’ extends the ‘HttpServlet’. Then i use serviceMethod() which will use to getting request from the doGet()Method for Output. Then load all the required Drivers. Then i declare some mandatory variables like connection (Connection variable is been used to make a bridge or link between database and actual code (java code)). As after creating link between both platforms, i declare resultSet, which will be use to fetch the values from required fields according to user. The other one variable is preparedStatement the object of this variable is ‘ps’ this will use to execute the query like executeQuery() as(SELECT name, salary, 12*(salary+100) cal FROM worker). To in the end i use doGet()Method for getting value on the web Browser.
For getting the output in the tabular form, i use ‘HTML’ code and tags that will show output in a manner way on 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 MySqlParanthesesJavaServlet 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 name, salary, 12*(salary+100) cal FROM worker");
rs = ps.executeQuery();
String title = "Employee's Info With Using Of Parantheses";
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>Name</th><th>Salary</th><th>Cal</th>\n"+ "</body> </html>");
while(rs.next())
{
String nm = rs.getString("name");
int sal = rs.getInt("salary");
int c=rs.getInt("cal");
disp.println("<tr><td align=\"center\">" + nm + "<td align=\"center\">" + sal +"<td align=\"center\">" + c +"</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>MySqlParanthesesJavaServlet</servlet-name>
<servlet-class>MySqlParanthesesJavaServlet</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlParanthesesJavaServlet</servlet-name>
<url-pattern>/MySqlParanthesesJavaServlet</url-pattern>
</servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular