What is java pojo class, java bean, normal class?

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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?

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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.

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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.

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最佳答案

  1. Normal Class: A Java class

  2. Java Beans:

    • All properties private (use getters/setters)
    • A public no-argument constructor
    • Implements Serializable.

  3. 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

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