not able to connect to the database

[Vas Miriyala]

got the following error when i try to run java program
Error

   
bash-3.2# java -cp . MysqlConnect
MySQL Connect Example.
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at MysqlConnect.main(MysqlConnect.java:13)

 

Here is the program

 
import java.sql.*;

public class MysqlConnect{
  public static void main(String[] args) {
    System.out.println("MySQL Connect Example.");
    Connection conn = null;
    String url = "jdbc:mysql://localhost:3306";
    String dbName = "IMS";
    String driver = "com.mysql.jdbc.Driver";
    String userName = "root"; 
    String password = "";
    try {
      Class.forName(driver).newInstance();
      conn = DriverManager.getConnection(url+dbName,userName,password);
      System.out.println("Connected to the database");
      conn.close();
      System.out.println("Disconnected from database");
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}
   

here is the classpath

   
bash-3.2# echo $CLASSPATH
/opt/jboss-5.1.0.GA/common/lib/servlet-api.jar:/opt/jboss-5.1.0.GA/common/lib/mysql-connector-java-5.1.6-bin.jar
bash-3.2#
 

any idea what is the problem

[Vijitha Kumara]

When you are using "-cp" switch the "CLASSPATH" environment variable will be ignored, to use the values contained within that you should add that to the "-cp" switch as well. java -cp $CLASSAPTH;. MysqlConnect

P.S:I'm not sure about the delimiter (i.e ; or :).

[Vas Miriyala]

thanks for your reply and got the error which says

 
bash-3.2# java -cp $CLASSPATH MysqlConnect
Exception in thread "main" java.lang.NoClassDefFoundError: MysqlConnect
bash-3.2# java -cp $CLASSPATH; MysqlConnect
Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)

where options include:
    -d32          use a 32-bit data model if available

    -d64          use a 64-bit data model if available
    -client       to select the "client" VM
    -server       to select the "server" VM
    -hotspot      is a synonym for the "client" VM  [deprecated]
                  The default VM is client.
                  
    -cp <class search path of directories and zip/jar files>
    -classpath <class search path of directories and zip/jar files>
                  A : separated list of directories, JAR archives,
                  and ZIP archives to search for class files.
    -D<name>=<value>
                  set a system property
    -verbose[:class|gc|jni]
                  enable verbose output
    -version      print product version and exit
    -version:<value>
                  require the specified version to run
    -showversion  print product version and continue
    -jre-restrict-search | -jre-no-restrict-search
                  include/exclude user private JREs in the version search
    -? -help      print this help message
    -X            print help on non-standard options
    -ea[:<packagename>...|:<classname>]
    -enableassertions[:<packagename>...|:<classname>]
                  enable assertions
    -da[:<packagename>...|:<classname>]
    -disableassertions[:<packagename>...|:<classname>]
                  disable assertions
    -esa | -enablesystemassertions
                  enable system assertions
    -dsa | -disablesystemassertions
                  disable system assertions
    -agentlib:<libname>[=<options>]
                  load native agent library <libname>, e.g. -agentlib:hprof
                    see also, -agentlib:jdwp=help and -agentlib:hprof=help
    -agentpath:<pathname>[=<options>]
                  load native agent library by full pathname
    -javaagent:<jarpath>[=<options>]
                  load Java programming language agent, see java.lang.instrument
    -splash:<imagepath>
                  show splash screen with specified image
bash: MysqlConnect: command not found
bash-3.2# 


   

[Vijitha Kumara]

bash-3.2# java -cp $CLASSPATH MysqlConnect

This should include the directory your class resides as well (this case I think current directory?). Try "java -cp $CLASSPATH;. MysqlConnect" OR "java -cp $CLASSPATH:. MysqlConnect"

[Vas Miriyala]

thats great...thanks Vijitha Kumara it working thanks again