java.lang.reflect.InaccessibleObjectException 时使用 @Configuration

问：

我通过以下示例向我的学生解释基于 Java 的配置。

我正在使用 JDK 17.0.7，Spring 版本 5.3.29。

有趣的是：如果我不@Configuration而是使用@Component或@Configurable它工作正常

文件 1：第 1 类

package java_config;

public class Book {
    private String name;
    private double price;

    public Book() {
        super();
    }

    public Book(String name, double price) {
        super();
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Book [name=" + name + ", price=" + price + "]";
    }

}

文件 2：第 2 类

package java_config;

public class Student {
    private String name;
    private String subject;
    private Book book;

    public Student() {
        super();
    }

    public Student(String name, String subject, Book book) {
        super();
        this.name = name;
        this.subject = subject;
        this.book = book;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSubject() {
        return subject;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public Book getBook() {
        return book;
    }

    public void setBook(Book book) {
        this.book = book;
    }

    @Override
    public String toString() {
        return "Student [name=" + name + ", subject=" + subject + ", book=" + book + "]";
    }

}

文件 3：第 3 类

package java_config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;

@Configuration
public class JavaConfig {

    @Bean
    public Book getBook() {
        return new Book("Let Us C", 200);
    }

    @Bean
    public Student getStudent() {
        return new Student("Ashutosh", "PCM", getBook());
    }
}

文件 4 ： 第 4 类

package java_config;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class JavaConfigurationDemo {

    public static void main(String[] args) {
        **// The below line is showing the exception 
        ApplicationContext ctx = 
                new AnnotationConfigApplicationContext(JavaConfig.class);**
        
        Student student = ctx.getBean("getStudent", Student.class);
        
        System.out.println("Student's book name : " + student.getBook().getName());
    }

}

输出：控制台中的异常

Exception in thread "main" org.springframework.cglib.core.CodeGenerationException: java.lang.reflect.InaccessibleObjectException-->Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @73f792cf
    at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:600)
    at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:363)
    at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:585)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:110)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:108)
    at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
    at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:134)
    at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:319)
    at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:572)
    at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:419)
    at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:137)
    at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:109)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:447)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:268)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:325)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:147)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:748)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:564)
    at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:93)
    **at java_config.JavaConfigurationDemo.main(JavaConfigurationDemo.java:10)**
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @73f792cf
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
    at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
    at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
    at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:552)
    ... 22 more