zoukankan      html  css  js  c++  java
  • Different ways to create an object in Java

    Different ways to create an object in Java

     

    You must have used the “new” operator to create an Object of a Class. But is it the only way to create an Object?

    Simple Answers is NO, then in how many ways we can create Object of a Class. There are several like

    • Using New keyword
    • Using New Instance (Reflection)
    • Using Clone
    • Using Deserilization
    • Using ClassLoader
    • … don’t know :)

    Now we will explore the different ways of creating the Object except new Operator.

    Using New Keyword

    Using new keyword is the most basic way to create an object. Use new keyword to create and Object of class.

     

    Using New Instance (Reflection)

    Have you ever tried to connect to any DB using JDBC driver in Java, If your answer is yes then you must have seen “Class.forName“. We can also use it to create the object of a class. Class.forName actually loads the class in Java but doesn’t create any Object. To Create an Object of the Class you have to use newInstance method of Class class.

    Note*: If you want to create Object in this way class needs to have public default Constructor.

    Using Clone

    We can also use Clone() method to create a copy of an existing Object.

     Note*:

    • Here we are creating the clone of an existing Object and not any new Object. 
    • Clone method is declared protected in Object class. So it can be accessed only in subclass or in same package. That is the reason why it has been overridden here in Class.
    • Class need to implement Cloneable Interface otherwise it will throw CloneNotSupportedException.
     

    Using Object Deserialization

    Object deserialization can also be used to create an Object. It is just the opposite of serializing an Object.

    Using ClassLoader

    We can also use Class Loader to create Object of a Class. This way is some what same as Class.forName option.

  • 相关阅读:
    常见水果的日语单词汇总
    身体各个部位的日语单词
    多拉A梦——日语歌词
    日语——动词的各种变形
    语言类型学分类
    常用自定义函数
    IOS 读取xib里的子控件
    IOS中 copy ,strong ,weak ,assign使用区别
    IOS 字典转模型
    IOS 纯代码添加 Button Image Label 添加到自定义View中
  • 原文地址:https://www.cnblogs.com/hephec/p/4556652.html
Copyright © 2011-2022 走看看