综上所述:相同点和不同点是:

   java beans:                          Pojo:
-must extends serializable              -no need to extends or implement.
 or externalizable.                     
-must have public class .               - must have public class
-must have private instance variables.      -can have any access specifier variables.
-must have public setter and getter method. - may or may not have setter or getter method.
-must have no-arg constructor.           - can have constructor with agruments.

所有JAVA bean都是POJO，但并非所有POJO都是JAVA bean。

POJOS具有某些约定(getter/setter，公共无参数构造函数，私有变量)，并且正在起作用(例如。用于按表单读取数据)是javabean。

根据Martin Fowler的说法，POJO是一个封装业务逻辑的对象，而Bean(除了已经在其他回答中陈述的定义之外)只不过是一个保存数据的容器，对象上可用的操作只是设置和获取数据。

The term was coined while Rebecca Parsons, Josh MacKenzie and I were preparing for a talk at a conference in September 2000. In the talk we were pointing out the many benefits of encoding business logic into regular java objects rather than using Entity Beans. We wondered why people were so against using regular objects in their systems and concluded that it was because simple objects lacked a fancy name. So we gave them one, and it's caught on very nicely. http://www.martinfowler.com/bliki/POJO.html

Java bean是特殊类型的pojo。

以下列出的特色是有道理的

POJO:如果这个类可以在底层JDK中执行，而不需要任何外部第三方库的支持，那么它就被称为POJO

JavaBean:如果类只包含带有访问器(setter和getter)的属性，则称为JavaBean。JavaBean通常不包含任何业务逻辑，而是用于保存一些数据。

所有的爪哇人都是POJO，但并非所有POJO都是爪哇人

所有的javabean都是pojo，但并非所有的pojo都是javabean。

JavaBean是满足某些编程约定的Java对象:

JavaBean类必须实现Serializable或Externalizable; JavaBean类必须有一个公共的无参数构造函数; 所有JavaBean属性必须有公共setter和getter方法(视情况而定); 所有JavaBean实例变量都应该是私有的。