The technical principles of the Reflext Framework API framework in the Java class library

Analysis of the technical principles of the Reflect Framework API framework in the Java class library Overview: In the Java class library, the Reflect Framework API provides a powerful mechanism to obtain, check and operate, interface, field, and methods during runtime.This mechanism enables developers to dynamically create, inspect and call objects, so as to play an important role in writing flexible and highly scalable code.This article will analyze the technical principles of the Reflect Framework API and provide some Java code examples to illustrate its usage. 1. Reflection principle Reflection refers to the ability to obtain and operate the internal information during the running of the program.Java's reflection mechanism allows developers to check and call categories, methods, fields, etc. during runtime.It provides this ability through the class and interfaces in the Java.lang.reflect package. 2. The core category of the reflection framework API The core category of the reflector API is the class class, which represents a class or interface in JVM.The Class class provides the following methods to check and operate the class and interface information: -getName (): Return the name of the class. -Getfields (): Returns public fields in the class. -getMethods (): Returns public methods in the class. -GetConStructors (): Returns the public structure function in the class. -NewInstance (): Create an instance of a dynamic creation by reflected. In addition to the Class class, the reflex framework API also provides the operation of the Field, the Method, and the Constructor class to provide the operation of fields, methods, and constructors. 3. Example of using the reflection framework API Here are some common example code that uses reflecting framework API: -The instance of the dynamic creation class: Class<?> clazz = Class.forName("com.example.MyClass"); Object obj = clazz.newInstance(); -Colon and call method: Class<?> clazz = obj.getClass(); Method method = clazz.getMethod("methodName", parameterTypes); Object result = method.invoke(obj, arguments); -Colon and set the field value: Class<?> clazz = obj.getClass(); Field field = clazz.getDeclaredField("fieldName"); field.setAccessible(true); Object value = field.get(obj); field.set(obj, newValue); Summarize: Through the Reflect Framework API, the Java class library provides a powerful mechanism to find, check and call class, interfaces, fields, and methods during runtime.The reflection mechanism enables developers to write high -scale scalable and flexible code, and dynamically create and operate objects.This article provides technical analysis of the reflex framework API and shows some examples of examples that use the API.