Java 未定义[]类型的限定bean

我刚开始学习Spring，并试图制作一个基本的Spring程序，但我无法解决这个错误。代码如下：

Student.java

@Component
public class Student {
private String name;

public String getName() {
    return name;
}

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

配置类

@Configuration
@ComponentScan("springfirst1")

public class ConfigClass {
public Student getStudent(){
    return new Student();
}
}

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext("ConfigClass.class");
    Student s1 = context.getBean(Student.class);
    s1.setName("Adam");
    System.out.println(s1.getName());
}       

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(ConfigClass.class);
    Student s1 = context.getBean(Student.class);
    s1.setName("Gaurav");
    System.out.println(s1.getName());
} 

主类

@Configuration
@ComponentScan("springfirst1")

public class ConfigClass {
public Student getStudent(){
    return new Student();
}
}

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext("ConfigClass.class");
    Student s1 = context.getBean(Student.class);
    s1.setName("Adam");
    System.out.println(s1.getName());
}       

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(ConfigClass.class);
    Student s1 = context.getBean(Student.class);
    s1.setName("Gaurav");
    System.out.println(s1.getName());
} 

}

错误：

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [springfirst1.Student] is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:318)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:985)
at springfirst1.SpringFirst1.main(SpringFirst1.java:13)

---

在

ApplicationContext

参数中进行以下更改可以解决此问题

主类

@Configuration
@ComponentScan("springfirst1")

public class ConfigClass {
public Student getStudent(){
    return new Student();
}
}

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext("ConfigClass.class");
    Student s1 = context.getBean(Student.class);
    s1.setName("Adam");
    System.out.println(s1.getName());
}       

public class SpringFirst1 {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(ConfigClass.class);
    Student s1 = context.getBean(Student.class);
    s1.setName("Gaurav");
    System.out.println(s1.getName());
} 

如果将@Component放在类的上方，则不需要这样做：

如果要使用java配置，必须将@Bean放在上面：

@Bean
public Student getStudent(){
  return new Student();
 }

---

编辑：检查Arun答案：-）

使用包声明更新Java类。如果AnnotationConfigApplicationContext参数中存在错误，则调试该问题会有所帮助。检查文档并更正，这将起作用。谢谢您的建议！