使用java反射，获取类的私有属性，调用类的私有方法

使用java反射，获取类的私有属性，调用类的私有方法

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class PrivateObject {
    
    

    private String privateString = null;   //声明为私有字段

    public PrivateObject(String privateString) {
    
    
        this.privateString = privateString;
    }

    private String getPrivateString() {
    
    //私有方法
        System.out.println("----------调用了私有方法-------------");
        return "-----私有方法------";
    }

    public static void main(String[] args) throws Exception {
    
    
        // getPrivateAttribure();
        callPrivateMethod();
    }

    private static void callPrivateMethod() throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
    
    
        PrivateObject privateObject = new PrivateObject("The Private Value");
        Method privateStringMethod = PrivateObject.class.getDeclaredMethod("getPrivateString", null);
        privateStringMethod.setAccessible(true);
        String returnValue = (String) privateStringMethod.invoke(privateObject, null);
        System.out.println("returnValue = " + returnValue);
    }

    private static void getPrivateAttribure() throws NoSuchFieldException, IllegalAccessException {
    
    
        PrivateObject privateObject = new PrivateObject("The Private Value");//实例化对象
        Field privateStringField = PrivateObject.class.getDeclaredField("privateString");
        privateStringField.setAccessible(true);//允许访问私有字段
        String fieldValue = (String) privateStringField.get(privateObject);//获得私有字段值
        System.out.println("fieldValue = " + fieldValue);
    }

}