/**
 * Custom CoundDownLach implementation
 * @author sandeep
 *
 */
public class CustomCountDownLatch
{
	int counter;

	public CustomCountDownLatch(int counter)
	{
		this.counter = counter;
	}

	public synchronized void await() throws InterruptedException
	{
		if (counter > 0)
		{
			wait();
		}
	}

	/**
	 * method will decrement the counter by 1 each time
	 */
	public synchronized void countDown()
	{
		counter--;
		if (counter == 0)
		{
			notifyAll();
		}
	}
}

import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class Hibernate4Util {
  private static SessionFactory sessionFactory;
  private static ServiceRegistry serviceRegistry;

  static {
    try {
      Configuration configuration = new Configuration().configure();

      serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties())
          .buildServiceRegistry();

      // pass ServiceRegistry in buildSessionFactory method.
      // buildSessionFactory() method without any argument is deprecated
      sessionFactory = configuration.buildSessionFactory(serviceRegistry);
    } catch (HibernateException e) {
      System.err.println("Error creating Session: " + e);
      throw new ExceptionInInitializerError(e);
    }
  }

  public static SessionFactory getSessionFactory() {
    return sessionFactory;
  }
}

import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class Hibernate3Util {
  private static SessionFactory sessionFactory;

  static {
    try {
      Configuration configuration = new Configuration().configure();
      sessionFactory = configuration.buildSessionFactory();
    } catch (HibernateException e) {
      System.err.println("Error creating Session: " + e);
      throw new ExceptionInInitializerError(e);
    }
  }

  public static SessionFactory getSessionFactory() {
    return sessionFactory;
  }
}

public interface BlockingQueue extends Queue

get(Locale locale, String key): String – LanguageUtil  
get(Locale locale, String key, String defaultValue) String – LanguageUtil  
get(PageContext pageContext, String key) String – LanguageUtil  
get(PageContext pageContext, String key, String defaultValue) String – LanguageUtil  
get(PortletConfig portletConfig, Locale locale, String key) String – LanguageUtil  
get(PortletConfig portletConfig, Locale locale, String key, String defaultValue) String – LanguageUtil

package com;  

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface NotNullAndNotEmpty {

}

package com;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

public class NotNullAndNotEmptyValidator {
  public static List<String> validate(Object obj) {
    List<String> errors = new ArrayList<String>();

    NotNullAndNotEmpty annotations = (NotNullAndNotEmpty) obj.getClass().getAnnotation(NotNullAndNotEmpty.class);

    // if annotation not found on class then return empty list
    if (annotations != null) {

      Field[] fields = obj.getClass().getDeclaredFields();
      for (Field field : fields) {
        field.setAccessible(true);
        try {
          if (field.get(obj) == null) {
            errors.add(field.getName() + " is null or empty");
          }
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }
    return errors;
  }
}  

package com;

@NotNullAndNotEmpty
public class Employee {
  private String name;
  private String address;

  public Employee() {

  }

  public Employee(String name, String address) {
    super();
    this.name = name;
    this.address = address;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public String getAddress() {
    return address;
  }

  public void setAddress(String address) {
    this.address = address;
  }

}

package com;

import java.util.List;

public class Test {

  public static void main(String[] args) {
    Employee emp = new Employee("Sandeep", null);

    List<String> errors = NotNullAndNotEmptyValidator.validate(emp);

    for (String error : errors) {
      System.out.println(error);
    }

  }
}

address is null or empty