How can you access private methods using Java reflectio…

Using Java reflection, you can access private methods by using the getDeclaredMethod() method, which can retrieve methods with specific names and parameter types, including private methods.

Here is an example code showing how to use reflection to access and invoke a private method:

import java.lang.reflect.Method;

public class ReflectionExample {
    private void privateMethod() {
        System.out.println("私有方法被调用");
    }

    public static void main(String[] args) throws Exception {
        // 获取类的Class对象
        Class<ReflectionExample> clazz = ReflectionExample.class;

        // 获取指定名称的私有方法
        Method privateMethod = clazz.getDeclaredMethod("privateMethod");

        // 设置私有方法可访问
        privateMethod.setAccessible(true);

        // 创建类的实例
        ReflectionExample example = clazz.newInstance();

        // 调用私有方法
        privateMethod.invoke(example);
    }
}

In the above code, the getDeclaredMethod() is used to access the privateMethod(), setAccessible(true) is used to make the private method accessible, and invoke() is used to call the private method.

Caution: When using reflection to call private methods, the private method needs to be made accessible, otherwise an IllegalAccessException exception will be thrown.