Detailed introduction and summary of java reflection mechanism knowledge

This article will describe the knowledge of reflection from the following aspects:

1、 What is a class

In the object-oriented world, everything is an object. Class is an object and class is Java Instance object of lang.class class. In addition, only the Java virtual machine can new the class. Any class is an instance object of class. This instance object can be expressed in three ways:

2、 Dynamic loading of class

Class. Forname (full name of the class); This method not only represents the type of class, but also represents the dynamically loaded class. The compile time loading class is static loading, and the run time loading class is dynamic loading.

3、 Get method information

The basic data type and void keyword are instances of class; You can use getame(); Getsimplename() gets the name of the class.

Get all the methods of the class and print them out:

function:

4、 Get information about member variables

You can also get the member variable information of the class

function:

5、 Get constructor information

function:

6、 Operation of method reflection

Get a method: you need to get the name and parameters of the method to determine a method.

Reflection operation of method:

for instance:

function:

This article has explained the basic usage of java reflection, which can judge the class of any object at run time; Construct the object of any class at runtime; Judge the member variables and methods of any class at run time; Call the method of any object at run time; Generate dynamic proxy.

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