Java APIs

Hello everyone, I am executing the next code...

import org.xml.sax.InputSource;
import javax.xml.xpath.*;
import org.apache.xpath.NodeSet;

public class peos {

public static void main(String[] args) {

try {

XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "/widgets/widget";
InputSource inputSource = new InputSource("C:\\catalog.xml");
NodeSet nodes = (NodeSet) xpath.evaluate(expression, inputSource,XPathConstants.NODESET);
} catch (Exception e) {}

}
}

and i get this exception...

java.lang.UnsupportedClassVersionError: peos (Unsupported major.minor version 49.0)

at java.lang.ClassLoader.defineClass0(Native Method)

at java.lang.ClassLoader.defineClass(ClassLoader.java:537)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)

at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)

at java.net.URLClassLoader.access$100(URLClassLoader.java:55)

at java.net.URLClassLoader$1.run(URLClassLoader.java:194)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:187)

at java.lang.ClassLoader.loadClass(ClassLoader.java:289)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)

at java.lang.ClassLoader.loadClass(ClassLoader.java:235)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)

Exception in thread "main"

I am using jBuilder 2005 foundation and searching on the internet to find more about the problem I changed the default project properties at Build -> java : the language features to JAVA 2 SDK v.5.0, (generics enabled) and the Target VM to All java SDKs but still I couldnt make it work. Any suggestions ?

Thank you in advance