ClassNotFoundException while trying to connect to Oracle

[Kiran kk]

hi my program is unable to connect to the database it shows the ClassNotFound Exception
Below is the Program

package model;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class ManageConnectionClass {
private String dbURL="jdbc:oracle:thin:@localhost:1521:ORCL";
private String dbUserName="system";
private String dbPassword="default";

public Connection getConnection(){
Connection conn=null;
try{
try {
Class.forName("oracle.jdbc.OracleDriver");
} catch (ClassNotFoundException e) {
System.out.println("Class not found");
System.out.println(e);
}
conn=DriverManager.getConnection(dbURL,dbUserName,dbPassword);
}
catch(SQLException e){
System.out.println("Could not connect to DB");
}
return conn;
}
public void putConnection(Connection conn){
if(conn!=null)
{
try {
conn.close();
}
catch (SQLException e)
{
System.out.println("Could not close the connection");

}
}
}


public static void main(String args[]){
try {
System.out.println(new ManageConnectionClass().getConnection());
} catch (Exception e) {
System.out.println("Exception"+e);
}
}
}
and i'm invoking this using the main method......... I wasted a whole day for this .... please help me out...

[Rajkamal Pillai]

Which line throws ClassNotFoundException?

[Kiran kk]

Raj Kamal wrote:
Which line throws ClassNotFoundException?

at this line

Class.forName("oracle.jdbc.OracleDriver");

[James Sabre]

You need to add the Oracle JDBC driver jar to your class path. When you use this in your servlet the driver jar must be placed in the WEB-INF/lib directory of your war file.

[Dieter Quickfend]

You probably need to put the right driver jar on your classpath.

[Kiran kk]

James Sabre wrote:You need to add the Oracle JDBC driver jar to your class path. When you use this in your servlet the driver jar must be placed in the WEB-INF/lib directory of your war file.

I'm using eclipse galileo.... still do i need to add? I added the classes12.jar file in my database connections....even the pinging also failed....

[James Sabre]

Kiran kk wrote:

I'm using eclipse galileo.... still do i need to add? I added the classes12.jar file in my database connections...

I no longer use Eclipse so I don't know the proper approach to this.

.even the pinging also failed....

I don't understand. How were you 'pinging'?

[Kiran kk]

i'm using eclipse galileo.. In that i created a new database connection selecting Oracle.... In the new Driver definition(oracle thin driver 10) i made modifications like removing the classes14 jar,adding the classes12 jar, setting the SID,username ,password... i made these modifications in the properties also... When i click the test connection button it says the ping failed

[Dieter Quickfend]

Then you have a problem connecting. Check if all your data is correct... Username, password, driver string, hostname, and port.

[James Sabre]

Dieter Quickfend wrote:Then you have a problem connecting. Check if all your data is correct... Username, password, driver string, hostname, and port.

This may be true BUT the original ClassNotFound exception still points to a classpath problem and I suspect this should be addressed first.

[amit punekar]

Hi,
Two things to check
1) Do you see the Class for which ClassNotFound is thrown in the JAR that you added in Eclipse
2) Right click the java project and check the Java Build Path. It should have correct location of the JDBC driver's Jar file.

Regards,
Amit

[Kiran kk]

Dieter Quickfend wrote:Then you have a problem connecting. Check if all your data is correct... Username, password, driver string, hostname, and port.

Username:system
password:default
driver string:jdbc:oracle:thin:@localhost:1521:ORCL
hostname:ORCL

the username and password are working as i checked that with my oracle sql puls..

[Kiran kk]

amit punekar wrote:Hi,
Two things to check
1) Do you see the Class for which ClassNotFound is thrown in the JAR that you added in Eclipse
2) Right click the java project and check the Java Build Path. It should have correct location of the JDBC driver's Jar file.

Regards,
Amit

Thank you Amit For your Reply The ClassNotFound problem is resolved but still i got SQL exception saying that the network adapter could not establish the connection

[Dieter Quickfend]

try using your real IP address instead of localhost.

[Kiran kk]

Dieter Quickfend wrote:try using your real IP address instead of localhost.

Thank you very much... It worked!!!The ping succeeded

[Dieter Quickfend]

You're welcome.

[Kiran kk]

Dieter Quickfend wrote:You're welcome.

This is my Servlet class

package control;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.AddMovieClass;
/**
 * Servlet implementation class AddmovieServlet
 */
public class AddmovieServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AddmovieServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		String mname=request.getParameter("moviename");
		String starcast=request.getParameter("starcast");
		String director=request.getParameter("director");
		String language=request.getParameter("language");
		String odate=request.getParameter("opendate");
		String cdate=request.getParameter("closedate");
		AddMovieClass mc=new AddMovieClass();
		//System.out.println("samba");
		mc.add(mname,starcast,director,language,odate,cdate);
		//System.out.println("siva");
		//response.sendRedirect("movieadded.jsp");
	}

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

}

This is the model class

package model;

import java.sql.Connection;
import java.sql.PreparedStatement;


public class AddMovieClass {
	
public void add(String mname,String starcast,String director,String language,String odate,String cdate){
	ManageConnectionClass mc=new ManageConnectionClass();
	try{
	Connection con=mc.getConnection();
	PreparedStatement ps=null;
	String sql="insert into pyramid values(?,?,?,?,?,?)";
	ps=con.prepareStatement(sql);
	ps.setString(1,mname);
	ps.setString(2,starcast);
	ps.setString(3,director);
	ps.setString(4,language);
	ps.setString(5,odate);
	ps.setString(6,cdate);
	ps.executeUpdate();
	mc.putConnection(con);
	}
	catch(Exception e)
	{
		System.out.println("Exception"+e);
	}
}
/*public static void main(String args[]){
	try {
		AddMovieClass mc=new AddMovieClass();
		mc.add("s","s","s","s","s","s");
		
	}
	catch (Exception e) {
		System.out.println(e);
	}
}*/
}

This is the class for getting connection to the Database

package model;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class ManageConnectionClass {
private String dbURL="jdbc:oracle:thin:@192.168.1.10:1521:ORCL";
private String dbUserName="system";
private String dbPassword="default";
public Connection conn=null;
public Connection getConnection(){
	
		 try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			System.out.println("Class found!!");
		     } 
		 catch (ClassNotFoundException e) {
			System.out.println("Class not found"+e);
			System.out.println(e);
			
		}
	   try{ 
		   conn=DriverManager.getConnection(dbURL,dbUserName,dbPassword);
		   System.out.println("connection successful!!");
	      }
	       catch(SQLException e){
	    	 System.out.println("Could not connect to DB"+e);
	    	 return null;
	         }
	return conn;
}
/*public static void main(String args[]){
	try {
		ManageConnectionClass mc=new ManageConnectionClass();
		
		System.out.println(mc.getConnection());
		mc.putConnection(mc.getConnection());
	}
	catch (Exception e) {
		System.out.println(e);
	}
}*/
public void putConnection(Connection conn){
if(conn!=null)
 {
	try {
		conn.close();
		System.out.println("Connection Closed!!");
     	}
	catch (SQLException e)
	{
		System.out.println("Could not close the connection");
		//e.printStackTrace();
	}
 }
}
}

This is the code to add a movie to the pyramid table.. When i executed it including main method the insertion is happened but when i removed the main method it's showing an error "Class not foundjava.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
11:10:11,022 INFO [STDOUT] java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
11:10:11,023 INFO [STDOUT] Could not connect to DBjava.sql.SQLException: No suitable driver found for jdbc:oracle:thin:@192.168.1.10:1521:ORCL
11:10:11,024 INFO [STDOUT] Exceptionjava.lang.NullPointerException"


How can i overcome this error? help me

[Peter Johnson]

You need to add the Oracle JDBC driver to your classpath. One way to do this in Eclipse is to add the JDBC JAR file to the project's build path.