import org.jivesoftware.smack.debugger.SmackDebugger; //导入依赖的package包/类
@Override
public SmackDebugger create(XMPPConnection connection, Writer writer, Reader reader) throws IllegalArgumentException {
    return new SLF4JSmackDebugger(connection, writer, reader);
}
 

import org.jivesoftware.smack.debugger.SmackDebugger; //导入依赖的package包/类
@Override
public SmackDebugger create(XMPPConnection connection, Writer writer, Reader reader) {
	return new JulDebugger(connection, writer, reader);
}
 

import org.jivesoftware.smack.debugger.SmackDebugger; //导入依赖的package包/类
/**
 * Creates new debugger instance with given arguments as parameters. May
 * return <code>null</code> if no DebuggerFactory is set or if the factory
 * did not produce a debugger.
 * 
 * @param connection
 * @param writer
 * @param reader
 * @return a new debugger or <code>null</code>
 */
public static SmackDebugger createDebugger(XMPPConnection connection, Writer writer, Reader reader) {
    SmackDebuggerFactory factory = getDebuggerFactory();
    if (factory == null) {
        return null;
    } else {
        return factory.create(connection, writer, reader);
    }
}