This Function Will Adds a period to a year-month.
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 ‘MySqlPeriodAddFunc’, which extends the ‘HttpServlet’. 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 PERIOD_ADD(20144,3)).The last instance will be to call the doGet()Method that will bring Output on the web browser.
To make output Impressive 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 MySqlPeriodAddFunc 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 PERIOD_ADD(20144,3) AS pa");
rs = ps.executeQuery();
String title = "Using Period Add 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>Result</th>\n"+ "</body> </html>");
while(rs.next())
{
String curr = rs.getString(1);
disp.println("<tr><td align=\"center\">" + curr +"</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>MySqlPeriodAddFunc</servlet-name>
<servlet-class>MySqlPeriodAddFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlPeriodAddFunc</servlet-name>
<url-pattern>/MySqlPeriodAddFunc</url-pattern>
</servlet-mapping>