23种设计模式的java代码

什么是设计模式？
设计模式就是在工作中经常遇到的一类问题的解决方案，是一种解决问题的方法，更是一种思想，是智慧的结晶。
设计模式是对被用来在特定场景下解决一般设计问题的类和相互通信的对象的描述。

package dps_01_build_type.dp01_singleton.eager.example1;

/**
 * 饿汉式单例（唯一角色即类本身）:

 * 在类被加载的时候，唯一实例已经被创建。这个设计模式在Java中容易实现，在别的语言中难以实现。

 * @author Administrator
 */
public class EagerSingleton {

  /**私有的（private）唯一（static final）实例成员在类加载的时候就创建好了单例对象*/
  private static final EagerSingleton instance = new EagerSingleton（）;

  /**
   * 私有构造函数避免从外部创建实例
   */
  private EagerSingleton（） {
  }

  /**
   * 静态工厂方法返回此类的唯一实例.

   * @return EagerSingleton      
   */
  public static EagerSingleton getInstance（） {
    return instance;
  }

}

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    .CA....       682  2009-08-11 13:15  DesignPattern\src\dps_01_build_type\dp01_singleton\eager\example1\EagerSingleton.java

    .CA....       601  2009-08-11 12:29  DesignPattern\src\dps_01_build_type\dp01_singleton\eager\example1\Test.java

    .CA....       756  2009-08-11 13:15  DesignPattern\src\dps_01_build_type\dp01_singleton\lazy\example1\LazySingleton.java

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    .CA....      1243  2009-08-10 17:39  DesignPattern\src\dps_01_build_type\dp02_factory\abstract_factory\example2\concrete_creator\DAOFactory.java

    .CA....       759  2009-08-10 17:39  DesignPattern\src\dps_01_build_type\dp02_factory\abstract_factory\example2\concrete_product\AccessDeptDAO.java

    .CA....       759  2009-08-10 17:39  DesignPattern\src\dps_01_build_type\dp02_factory\abstract_factory\example2\concrete_product\AccessUserDAO.java

    .CA....       773  2009-08-10 17:39  DesignPattern\src\dps_01_build_type\dp02_factory\abstract_factory\example2\concrete_product\SqlServerDeptDAO.java

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