import gov.nih.nci.cagrid.advertisement.exceptions.UnregistrationException; //导入依赖的package包/类
protected AdvertisementClient() {
    this.client = new ServiceGroupRegistrationClient();
    this.client.setClientCallback(new Callback());
   	System.out.println("Installing JVM shutdown hook to unregister.");
    Runtime.getRuntime().addShutdownHook(new Thread() {
        @Override
        public void run() {
           	System.out.println("Running shutdown hook.");
            try {
                unregister();
            } catch (UnregistrationException e) {
           		System.err.println("Problem unregistering");
           		System.err.println(e);
            }
        }
    });
}
 

import gov.nih.nci.cagrid.advertisement.exceptions.UnregistrationException; //导入依赖的package包/类
/**
 * Can be called to cancel any existing registration, and repurpose the
 * client for new registrations.
 * 
 * @param registrationConfig
 * @throws InvalidConfigurationException
 *             if the specified config is invalid (in this case the client
 *             remains in the old state). An invalid config is one which is
 *             null, or has a null servicegroup or registrant epr
 */
public void reinitialize(ServiceGroupRegistrationParameters registrationConfig)
    throws InvalidConfigurationException {
    if (registrationConfig == null) {
        throw new InvalidConfigurationException("Cannot use null parameters.");
    }
    if (registrationConfig.getRegistrantEPR() == null) {
        throw new InvalidConfigurationException("Must specify a non-null registrant.");
    }
    if (registrationConfig.getServiceGroupEPR() == null) {
        throw new InvalidConfigurationException("Must specify a non-null service group.");
    }

    try {
        unregister();
    } catch (UnregistrationException e) {
        // ignore this, as client is requesting a new registration, and
        // nothing they can do to correct problems with the existing one
        LOG.error("Problem unregistering existing entry", e);
    }
    this.sgParams = registrationConfig;
}
 

import gov.nih.nci.cagrid.advertisement.exceptions.UnregistrationException; //导入依赖的package包/类
/**
 * Unregisters from the service group
 */
public void unregister() throws UnregistrationException {
    if (this.sgParams == null) {
        return;
    }
    System.out.println("Unregistering " + printServiceGroupRegistrationParameters(this.sgParams));
    this.client.terminate();
    TerminationClient termClient = new TerminationClient(this.sgParams.getServiceGroupEPR());
    if (this.sgParams.getSecurityDescriptorFile() != null) {
        termClient.setSecurityDescriptorFile(this.sgParams.getSecurityDescriptorFile());
    }
    int unregisterCount = termClient.unregister(this.sgParams.getRegistrantEPR());
    System.out.println("Unregistered " + unregisterCount + " service entries.");
}