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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
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| JDBC|Servlets : Tomcat Connection Pooling - DBCP- Oracle |
EmployeeInfoServlet.java
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
public class EmployeeInfoServlet extends HttpServlet
{
private static final long serialVersionUID = 1L;
DataSource dataSource = null;
public void init( ServletConfig config )
{
try
{
System.out
.println("-----------------------------------------------------");
System.out
.println("init method has been called and servlet is initialized");
/*
* Using JDNI lookup get the DataSource.
*/
Context initContext = new InitialContext();
Context envContext = (Context) initContext.lookup("java:/comp/env");
dataSource = (DataSource) envContext.lookup("jdbc/HRDB");
System.out.println("Using JDNI lookup got the DataSource : "
+ dataSource);
System.out
.println("-----------------------------------------------------");
}
catch( Exception exe )
{
exe.printStackTrace();
}
}
public void doGet( HttpServletRequest request, HttpServletResponse response )
throws ServletException, IOException
{
System.out
.println("-----------------------------------------------------");
System.out.println("doGet method has been called");
System.out
.println("-----------------------------------------------------");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String title = "Employee Information From Oracle Database";
out.print("<html><body bgcolor=\"#f0f0f0\">");
out.print("<h1 align=\"center\">" + title + "</h1>\n");
showEmployeeInformation(out);
out.print("</body></html>");
}
public void destroy()
{
System.out
.println("-----------------------------------------------------");
System.out
.println("destroy method has been called and servlet is destroyed");
System.out
.println("-----------------------------------------------------");
}
private void showEmployeeInformation( PrintWriter out )
{
Connection connection = null;
Statement stmt = null;
try
{
/*
* Get connection from the DataSource
*/
connection = dataSource.getConnection();
/*
* Execute the Query
*/
stmt = connection.createStatement();
String sql = "select employee_id,first_name,last_name,email,phone_number from employees";
ResultSet rs = stmt.executeQuery(sql);
/*
* Iterate the ResultSet and get each row Information.
*/
while( rs.next() )
{
/*
* Retrieve by column name
*/
int id = rs.getInt("employee_id");
String firstName = rs.getString("first_name");
String lastName = rs.getString("last_name");
String email = rs.getString("email");
String phoneNumber = rs.getString("phone_number");
/*
* Display values
*/
out.print("employee_id: " + id+"<br>");
out.print("first_name: " + firstName+"<br>");
out.print("last_name: " + lastName+"<br>");
out.print("email: " + email+"<br>");
out.println("phone_number: " + phoneNumber+"<br>");
out.println("-------------------------------------------");
}
rs.close();
}
catch( Exception e )
{
e.printStackTrace();
}
finally
{
/*
* finally block used to close resources
*/
try
{
if( stmt != null )
{
stmt.close();
}
}
catch( SQLException sqlException )
{
sqlException.printStackTrace();
}
try
{
if( connection != null )
{
connection.close();
}
}
catch( SQLException sqlException )
{
sqlException.printStackTrace();
}
}
}
}
