Servlet Connection pool eaxmple

Connection pooling:

 

Create context.xml

Create employee class

package com.jsl.servlet.demo;

public class Employee {
        private int empno;
        private String ename;
        private String job;
        private double sal;
        public int getEmpno() {
            return empno;
        }
        public void setEmpno(int empno) {
            this.empno = empno;
        }
        public String getEname() {
            return ename;
        }
        public void setEname(String ename) {
            this.ename = ename;
        }
        public String getJob() {
            return job;
        }
        public void setJob(String job) {
            this.job = job;
        }
        public double getSal() {
            return sal;
        }
        public void setSal(double sal) {
            this.sal = sal;
        }
}

Creating a EmployeeServlet Class

   

package com.jsl.servlet.demo;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
 
@WebServlet("/getEmployee")
public class EmployeeServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    Connection con=null;
    Statement st=null;
    ResultSet rs=null;
    DataSource ds=null;
    Context cx=null;
    @Override
    public void init() throws ServletException {
            try {
                cx=new InitialContext();
                Context envContext = (Context) cx.lookup("java:/comp/env");
                ds = (DataSource) envContext.lookup("jdbc/employee");
 
            } catch (NamingException e) {
                e.printStackTrace();
            }
            
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            PrintWriter out=response.getWriter();
            response.setContentType("text/html");
            out.print("");
            out.print("");
            List list=getEmployeeList();
            out.print("");
            out.print("");
            for(Employee emp:list){
                out.print("");
                out.print("");
                out.print("");
                out.print("");
                
            }
            out.print("

EmpNo
Empname
Job
Sal
"+emp.getEmpno()+"
"+emp.getEname()+"
"+emp.getJob()+"
"+emp.getSal()+"

");
            
        out.print("");
        out.print("");
    }
    private List getEmployeeList() {
        List emplist=new ArrayList();
        try{
            con=ds.getConnection();
            st=con.createStatement();
            rs=st.executeQuery("select empno,ename,job,sal from emp");
            while(rs.next()){
                Employee emp=new Employee();
                emp.setEmpno(rs.getInt("empno"));
                emp.setEname(rs.getString("ename"));
                emp.setJob(rs.getString("job"));
                emp.setSal(rs.getDouble("sal"));
                emplist.add(emp);
            }
            
        }catch(Exception e){
            e.printStackTrace();
        }
        
        return emplist;
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            doGet(request, response);
    }
}

http://localhost:8089/Employee/getEmployee

 Download the SourceCode     Download the post

Hibernate Simple Example

Download distribution  file

http://sourceforge.net/projects/hibernate/files/hibernate3/3.6.10.Final/hibernate-distribution-3.6.10.Final-dist.zip/download

Extract the zip file

Create new java project

then add the  lib folder copy the all the jar

Member.java

package com.jsl.hibernate.demo;
public class Member {

  private int mid;
  private String name;
  private String email;
  private String city;
  
  public void setMid(int mid) {
   this.mid = mid;
  }
  public int getMid() {
   return mid;
  }
  public void setName(String name) {
   this.name = name;
  }
  public String getName() {
   return name;
  }
  public void setEmail(String email) {
   this.email = email;
  }
  public String getEmail() {
   return email;
  }
  public void setCity(String city) {
   this.city = city;
  }
  public String getCity() {
   return city;
  }
}

hibernate.cfg.xml

  
   
        oracle.jdbc.driver.OracleDriver
        jdbc:oracle:thin:@localhost:1521:xe
        java
        java

        
        1

        
        org.hibernate.dialect.OracleDialect


        
        true

        
        create

        

    

 

member.hbm.xml

Manager.java

package com.jsl.hibernate.demo;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class Manager {
  public static void main(String[] args) {
   Member member=new Member();
   member.setMid(1001);
   member.setName("Krish");
   member.setEmail("krish@gmail.com");
   member.setCity("Bangalore");
   
   SessionFactory factory=new Configuration().configure().buildSessionFactory();
   Session session=factory.openSession();
   org.hibernate.Transaction tx=session.beginTransaction();
   session.save(member);
   tx.commit();
   session.close();
  }
}

if run the manger.java the output will be

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

Hibernate: insert into MEMBER (NAME, EMAIL, CITY, MID) values (?, ?, ?, ?)