Java library uses the REFLECTIONS framework to obtain the information and attributes of the class
In the Java library, the Reflections framework is a very useful tool that allows us to obtain the information and attributes of the class at runtime.Through the REFLECTIONS framework, we can not know the specific name of the class in advance during compilation, but directly obtain the relevant information of the class through the reflection mechanism.
The Java reflection mechanism allows us to check, call and instantiate the class during runtime, and obtain the method and field of the class.The REFLECTIONS framework scan and analyze the class to help us easily obtain the information and attributes of the class.
First, we need to introduce the dependencies of the Reflections framework in the project.It can be implemented by adding the following code to the Maven configuration file of the project::
<dependency>
<groupId>org.reflections</groupId>
<artifactId>reflections</artifactId>
<version>0.9.12</version>
</dependency>
Then, in the Java code, we can use the API of the Reflections framework to obtain the information and attributes of the class.Here are some commonly used examples:
1. Get all the classes under the specified package:
import org.reflections.Reflections;
public class ClassInfoExample {
public static void main(String[] args) {
Reflections reflections = new Reflections("com.example.package");
Set<Class<?>> classes = reflections.getSubTypesOf(Object.class);
for (Class<?> clazz : classes) {
System.out.println(clazz.getName());
}
}
}
2. All methods to obtain a class:
import org.reflections.ReflectionUtils;
public class MethodInfoExample {
public static void main(String[] args) {
Class<?> clazz = MyClass.class;
Set<Method> methods = ReflectionUtils.getAllMethods(clazz);
for (Method method : methods) {
System.out.println(method.getName());
}
}
}
3. Get all the fields of the class:
import org.reflections.ReflectionUtils;
public class FieldInfoExample {
public static void main(String[] args) {
Class<?> clazz = MyClass.class;
Set<Field> fields = ReflectionUtils.getAllFields(clazz);
for (Field field : fields) {
System.out.println(field.getName());
}
}
}
By using the REFLECTIONS framework, we can dynamically obtain the information and attributes of the class, which is very useful for some applications that need to obtain classes at runtime and processed accordingly.Regardless of the implementation of the plug -in system, the ORM framework, or writing an automated test, the Reflections framework can provide convenience and flexibility.
To sum up, the Reflections framework provides us with a convenient way to obtain information and attributes of Java.Through it, we can directly obtain the relevant information of the category through the reflection mechanism during runtime, without having to know the specific name of the class in advance.This enables us to handle the Java class more flexibly and check, call and instance when needed.
