Question

Using JDK1.6.0_16, I have this simple program where I am trying to get beanshell 2.0b4 to load a .jar dynamically (as the documentation suggests it will do) and I am having no luck. The documentation says that if I use beanshells’ getClass() method then it will load jars that were previously loaded by the “addClassPath()” method. It is not working. I need help on this…

//debug();
addClassPath("mysql-connector-java-5.1.15.jar"); 
import com.mysql.jdbc.Driver; 
import java.sql.Connection;  
import java.sql.DriverManager; 
import java.util.Arrays;

System.out.println("MySQL Connect Example.");
System.out.println("Classpath: " + Arrays.toString( getClassPath() ) + "\n");

Connection conn = null;
String url = "jdbc:mysql://localhost:3306/";
String dbName = "test";
String driver = "com.mysql.jdbc.Driver";
String userName = "root"; 
String password = "password";
try {
  Class driverClass = getClass( driver );
  if(driverClass != null) {
    Driver driver = driverClass.newInstance();
    if(driver != null) {
      DriverManager.registerDriver(driver);
    }
  }
  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();
}

This problem I am having strongly suggests that the getClass() method (of beanshell) is unable to see its own dynamically changed classpath.

NOTE: this code works only when I put the mysql.jar file into the jre/lib/ext directory (which is where the legacy jre classloader can load it; not the beanshell classloader)

Answer 1

this is probably not a beanshell thing, jdbc has issues loading drivers across classloaders (check out the class javadoc for ClassLoader, and see hacks like this).