Print JNDI tree

At one point or another most of us would have wanted to see what was in the JNDI tree of the Application Server. This may have been because of a javax.naming.NameNotFoundException thrown by the application under development.

After scouring the internet and not finding a way to do this seemingly simple task, I put this together in about an hours time.

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;

public class JNDITree {
private Context context = null;

public static void main(String[] args) throws Exception {
new JNDITree().printJNDITree("");
System.out.println("DONE");
}

public JNDITree() throws NamingException {
setEnv();
}

/* Please modify this method or comment and use jndi.properties
*/
public void setEnv() throws NamingException {
Hashtable env = new Hashtable();
//OC4J
//  env.put(Context.INITIAL_CONTEXT_FACTORY, "com.evermind.server.rmi.RMIInitialContextFactory");
//  env.put(Context.PROVIDER_URL, "ormi://172.16.x.x:12404");
//  env.put(Context.SECURITY_PRINCIPAL, "admin");
//  env.put(Context.SECURITY_CREDENTIALS, "welcome");
//JBOSS
//  env.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
//  env.put(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
//  env.put(Context.PROVIDER_URL, "jnp://172.16.x.x:1099");
//WEBLOGIC
//  env.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
//  env.put(Context.PROVIDER_URL, "t3://172.16.x.x:7001");


context = new InitialContext(env);
}

public void printJNDITree(String ct)   {
try {
 printNE(context.list(ct), ct);
} catch (NamingException e) {
 //ignore leaf node exception
}
}

private void printNE(NamingEnumeration ne, String parentctx) throws NamingException {
while (ne.hasMoreElements()) {
 NameClassPair next = (NameClassPair) ne.nextElement();
 printEntry(next);
 increaseIndent();
 printJNDITree((parentctx.length() == 0) ? next.getName() : parentctx + "/" + next.getName());
 decreaseIndent();
}
}

private void printEntry(NameClassPair next) {
System.out.println(printIndent() + "-->" + next);
}


private int indentLevel = 0;

private void increaseIndent() {
indentLevel += 4;
}

private void decreaseIndent() {
indentLevel -= 4;
}

private String printIndent() {
StringBuffer buf = new StringBuffer(indentLevel);
for (int i = 0; i < indentLevel; i++) {
 buf.append(" ");
 }
 return buf.toString();
}

This seemed to have worked very well for me and I thought I'd share it incase any of you have the same need.
In case anyone has a better way of doing this, kindly comment.

P.S. Dont forget to edit the setEnv() method to set the InitialContext. Default values have been given for a few App Servers.
Alternatively, comment the method out and use jndi.properties with values corresponding to your application server.