Hi friend,

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class SumRowExample extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Connection con = null;
String url = "jdbc:mysql://localhost:3306/";;
String db = "register";
String driver = "com.mysql.jdbc.Driver";
int amount= 0;
try{
Class.forName(driver);
con = DriverManager.getConnection(url+db,"root","root");
try{
Statement st = con.createStatement();
ResultSet res = st.executeQuery("SELECT SUM(amount) FROM information");
while(res.next()){
amount = res.getInt(1);
}
out.println("Total amount:" + amount);
}
catch (SQLException ex){
System.out.println("SQL statement is not executed!");
}
}
catch (Exception e){
e.printStackTrace();
}
}
}


----------------------------


<servlet>
<servlet-name>sumrow</servlet-name>
<servlet-class>SumRowExample</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>sumrow</servlet-name>
<url-pattern>/SumRowExample</url-pattern>
</servlet-mapping>

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read for more information,

http://www.roseindia.net/servlets/