idgeneratorfactory.java

100多M的J2EE培训内容

package com.borland.training.meetings.entities;

// This is a factory class that encapsulates creating a concrete primary key
// generation algorithm, making future changes of this algorithm easy.

public class IdGeneratorFactory {

  private static IdGeneratorFactory instance = null;
  private IdGenerator generator;

  private IdGeneratorFactory() {
    generator = SimpleIdGenerator.getInstance();
  }

  public static IdGeneratorFactory getInstance() {
    if(instance == null) {
      instance = new IdGeneratorFactory();
    }
    return instance;
  }

  public IdGenerator getGenerator() {
    return generator;
  }
}