What are the calling methods of java reflection

Java reflection calling methods include: 1. Class class; 2. Constructor class; 3. Method class; 4. Field class; 5. ClassLoader class. Detailed introduction: 1. Class class, used to obtain class information, including class name, member variables and methods, etc. You can create an instance of the class through the "newInstance()" method of Class class; 2. Constructor class, used to obtain Constructor parameter types, modifiers, return types and other information, etc.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

Java reflection means that in the running state, for any entity class, all properties and methods of this class can be known; for any object, any of its properties and methods can be called. This method of dynamically obtaining the content of a class and dynamically calling objects is called reflection mechanism.

The Java reflection mechanism mainly provides the following functions:

1. Determine the class to which any object belongs at runtime.

2. Construct an object of any class at runtime.

3. Determine the member variables and methods of any class at runtime.

4. Call the method of any object at runtime.

Java's reflection mechanism is mainly used to analyze class capabilities, and can obtain information about members and members of each type in a program or assembly at runtime. The general object types in the program are confirmed during compilation, and Java's reflection mechanism can dynamically create objects and call their properties during runtime. Therefore, the core of reflection is to dynamically load classes or call methods to access properties during runtime. It does not need to know in advance who the running object is.

The following are commonly used calling methods in Java reflection:

1. Class class: is used to obtain class information, including the name of the class , member variables and methods, etc. An instance of a class can be created through the newInstance() method of the Class class.

2. Constructor class: Used to obtain information such as parameter types, modifiers, and return types of the constructor. You can use the newInstance(Object[] args) method of the Constructor class to create an instance of the class and pass the parameters.

3. Method class: Used to obtain the parameter type, return type, modifier and other information of the method. You can use the invoke(Object obj, Object[] args) method of the Method class to call the method and pass the parameters.

4. Field class: Used to obtain the type, modifier, name and other information of the field. You can use the get(Object obj) method of the Field class to get the value of the field, and use the set(Object obj, Object value) method to set the value of the field.

5. ClassLoader class: is used to load classes. You can use the loadClass(String name) method of the ClassLoader class to load classes.

In addition to the above basic methods, Java reflection also provides many other methods, such as array operations, annotation operations, type conversion, etc. It should be noted that the use of reflection may affect the performance and security of the program, so you should try to avoid using reflection frequently, or only use it when necessary.

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