Java Runtime Error

[suraj sheikh]

Hi,

After surfing the World Wide Web, i got very little. It seems this is the only play where i can get help

Here is the problem :

I have a java program :

package com.system33.model;
import java.sql.*;
public class MyOracleConnection {
public Connection connectionDriver() {
Connection conn=null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc racle:thin:@localhost:1521:XE", "system","administrator");
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(" "+conn);
return conn;
}
public String fetchData() {
String result="test";
try {
MyOracleConnection obj = new MyOracleConnection();
Connection c=obj.connectionDriver();
Statement stmt = c.createStatement();
String query="select * from boaiw";
ResultSet rs = stmt.executeQuery(query);
while(rs.next()) {
System.out.println(rs.getString(1));
result=rs.getString(1);
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
public static void main(String[] args) {
MyOracleConnection obj=new MyOracleConnection();
System.out.println(obj.fetchData());
}
}

And i am usign this to get a connection with the database from a servlet,

the directory structure is :
C:\My Projects\BoaIntegratedWorkflow>java MyOracleConnection

It compiles fine,

but when i try to execute it the unwanted thing happens,

Exception in thread "main" java.lang.NoClassDefFoundError: MyOracleConnection (wrong name: com/system33/model/MyOracleConnection)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)


this is no less than BLUE SCREEN OF DEATH for me.

It works fine and fetches data if i drop package declararion/defination at the begining..



PLEASE HELP ME...PLEASE HELP ME....PLEASE HELP ME...

This is my last hope, or i have to move to COBOL, ha ha
[ August 08, 2008: Message edited by: David O'Meara ]

[Sachin Joshi]

You need to set the CLASSPATH envirnoment variable for the directory where you are storing the .class file.

If your MyOracleConnection.class file is in C:\MyCode directory then use this command

SET CLASSPATH=%CLASSPATH%;C:\MyCode

Then execute the java command it should work.

You may need to do this every time you close and reopen the Command prompt window.

Other way to avoid doing it again and again would be to go to

Right Click on My Computer -> Properties -> Advanced -> Environment Variables
Here create a new variable CLASSPATH (remember all caps and no mistake in spelling )

Enter the value C:\MyCode here ....

Hope this would help...

[David O'Meara]

If it is packaged as com.system33.model then it should exist somewhere on the runtime classpath as the file com/system33/model/MyOracleConnection.class

Once it is on the runtime classpath, you would run it as java com.system33.model.MyOracleConnection

It appears that the class was compiled correctly, but neither its location on the file system nor the method of execution are correct

[Sachin Joshi]

Another thing I just noticed....

Looks like you have a package structure com/system33/model/MyOracleConnection

in this case you need to run the file like this

java com.system33.model.MyOracleConnection

[Nitesh Kant]

I think you must go through these tutorials:

CommonProblems
Packages