java反射修改属性值

package com.mtons.mblog;

/**
 * java反射修改属性值
 */

import java.lang.reflect.Field;

public class FinalTest {

    private final double a;

    {
        Class<FinalTest> aClass = FinalTest.class;
        Field field = null;
        try {
            field = aClass.getDeclaredField("a");
            field.setAccessible(true);
            // field.set(this, 1000.0);
            Object o = field.get(this);
            System.err.println(o);
        } catch (NoSuchFieldException | IllegalAccessException e) {
            e.printStackTrace();
        }
    }

    public FinalTest() {
        this.a = 10.0;
    }

    public static void main(String[] args) throws Exception {
        FinalTest test = new FinalTest();
        System.out.println(test.a);
    }

}