database

package DatabaseAccess;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.*;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class database_servlet
 */
@WebServlet("/database_servlet")
public class database_servlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public database_servlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // JDBC driver name and database URL
          String JDBC_DRIVER = "com.mysql.jdbc.Driver";
          String DB_URL="jdbc:mysql://localhost/servlet_test";

          //  Database credentials
          String USER = "root";
          String PASS = "";

          // Set response content type
          response.setContentType("text/html");
          PrintWriter out = response.getWriter();
          String title = "Database Result";

          String docType =
             "<!doctype html public \"-//w3c//dtd html 4.0 " + "transitional//en\">\n";

          out.println(docType +
             "<html>\n" +
             "<head><title>" + title + "</title></head>\n" +
             "<body bgcolor = \"#f0f0f0\">\n" +
             "<h1 align = \"center\">" + title + "</h1>\n");
          Connection conn = null;
          Statement stmt = null;

          try {
             // Register JDBC driver
             Class.forName("com.mysql.jdbc.Driver");

             // Open a connection
             conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/servlet_test","root","");

             // Execute SQL query
             stmt = conn.createStatement();
             String sql;
             sql = "SELECT id, first, last, age FROM employees";
             ResultSet rs = stmt.executeQuery(sql);

             // Extract data from result set
             while(rs.next()){
                //Retrieve by column name
                int id  = rs.getInt("id");
                int age = rs.getInt("age");
                String first = rs.getString("first");
                String last = rs.getString("last");

                //Display values
                out.println("ID: " + id + "<br>");
                out.println(", Age: " + age + "<br>");
                out.println(", First: " + first + "<br>");
                out.println(", Last: " + last + "<br>");
             }
             out.println("</body></html>");

             // Clean-up environment
             rs.close();
             stmt.close();
             conn.close();
          } catch(SQLException se) {
             //Handle errors for JDBC
             System.out.println(se);
          } catch(Exception e) {
             //Handle errors for Class.forName
              //System.out.println("hello");
             e.printStackTrace();
          } finally {
             //finally block used to close resources
             try {
                if(stmt!=null)
                   stmt.close();
             } catch(SQLException se2) {
             } // nothing we can do
             try {
                if(conn!=null)
                conn.close();
             } catch(SQLException se) {
                se.printStackTrace();
             } //end finally try
          } //end try
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}