What is java pojo class, java bean, normal class? [duplicate]

问题

Possible Duplicate:
Difference between DTO, VO, POJO, JavaBeans?

Hi please don\'t say my question is duplicate :-) I saw all questions but didn\'t understand the exact difference.

Can someone explain what is POJO, Bean, Normal Class in easy language?

回答1:

Normal Class: A Java class
Java Beans:
- All properties private (use getters/setters)
- A public no-argument constructor
- Implements Serializable.
Pojo: Plain Old Java Object is a Java object not bound by any restriction other than those forced by the Java Language Specification. I.e., a POJO should not have to
- Extend prespecified classes
- Implement prespecified interface
- Contain prespecified annotations

回答2:

POJO stands for Plain Old Java Object, and would be used to describe the same things as a "Normal Class" whereas a JavaBean follows a set of rules. Most commonly Beans use getters and setters to protect their member variables, which are typically set to private and have a no-argument public constructor. Wikipedia has a pretty good rundown of JavaBeans: http://en.wikipedia.org/wiki/JavaBeans

POJO is usually used to describe a class that doesn't need to be a subclass of anything, or implement specific interfaces, or follow a specific pattern.

回答3:

POJO = Plain Old Java Object. It has properties, getters and setters for respective properties. It may also override Object.toString() and Object.equals().

Java Beans : See Wiki link.

Normal Class : Any java Class.

来源：https://stackoverflow.com/questions/12517905/what-is-java-pojo-class-java-bean-normal-class

标签

java

class

javabeans

pojo