Java program to Connect to database

[Kerin Kapoor]

Hi,

I'm trying to write a simple java program to connect to Oracle database using Jrockit as my jvm.. Jrockit is being used by another 3rd party app (weblogic). I'm just using it to run my simple java program.

I'm new to java so following the steps provided here http://www.javacamp.org/moreclasses/jdbc/jdbc.html

The program gets compiled but I get the below error while running the program -

java.lang.classNotFoundException: 3Doracle.jdbc.driver.OracleDriver
JDBC Class found
SQL exception occured java.sql.SQLException: No suitable driver found for jdbc: oracle thin:@hostname:port:dbname

Please let me know the steps that need to be followed to make this connection work.

import java.sql.*;
public class Uname {
  public static void main(String[] args) {
   
try {
 
    Class.forName("oracle.jdbc.driver.OracleDriver"); //for Oracle driver
   // Class.forName("3Doracle.jdbc.driver.OracleDriver");
} catch(ClassNotFoundException e) {
    System.err.println("Error loading driver: " + e);
}  
/*	try {
        Class.forName("org.apache.derby.jdbc.ClientDriver");
     }
     catch(ClassNotFoundException e) {
       System.out.println("Class not found "+ e);
     }
*/	 
     System.out.println("JDBC Class found");
     int no_of_rows = 0;
     try {
        //Connection con = DriverManager.getConnection("jdbc:derby://hostname:port/testdb","username","password");  
        Connection con = DriverManager.getConnection("jdbc:oracle:thin:@hostname:port:testDB","username","password");   
		Statement stmt = con.createStatement();
        ResultSet rs = stmt.executeQuery
        ("SELECT * FROM tablename");
        while (rs.next()) {
           no_of_rows++;
        }
        System.out.println("There are "+ no_of_rows 
        + " record in the table");
     }
     catch(SQLException e){
        System.out.println("SQL exception occured" + e);
     }
  }
}

If I go to wlserver_10.3/server/ext/jdbc/oracle/11g..I can see the ojdbc5_g.jar,ojdbc5.jar,ojdbc6dms.jar, ojdbc6_g.jar, orai18n.jar, orai18n-mapping.jar files - which means the oracle driver is present.. but how do I use it ???

Thanks in Advance!

[Jeanne Boyarsky]

That error typically means that Oracle driver isn't in your classpath. Try running the program as

On Windows:
java -cp "/path/to/Oracle/driver/oracleDriver.jar;." Uname

On UNIX/Linux/Mac:
java -cp "/path/to/Oracle/driver/oracleDriver.jar:." Uname

[Kerin Kapoor]

Hi,

Thanks for the reply..

I've tried the below -
1. Compile - ./javac /app/utils/Uname.java

2. Run - ./java -cp "/app/wlserver_10.3/server/lib/ojdbc6.jar:." /app/utils/ Uname

But step 2 throws an error. I've tried the step2 without double quotes but no luck. The error is given below -

Exception in thread "Main Thread" java.lang.NoClassDefFoundError: /app/utils
Caused by : java.lang.ClassNotFoundException: .ap01.cap.hyperion.utils
at java.net. URLClassLoader$1.run(URLClassLoader.java.202)
at java.net. URLClassLoader.findClass(URLClassLoader.java.190)
at java.lang.ClassLoader.Loadclass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.LoadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: /app/utils/. Program will exit

Any pointers will be appreciated. I'm using Jrockit jvm installed with weblogic server...

Thanks in advance!!

[Jeanne Boyarsky]

You have two choices:

Option 1 - run from directory with code
cd into /app/utils
Run - ./java -cp "/app/wlserver_10.3/server/lib/ojdbc6.jar:." Uname

Option 2 - specify the directory the code is in
Run - ./java -cp "/app/wlserver_10.3/server/lib/ojdbc6.jar:/app/utils" Uname