Question

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

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();
}
}

主要类

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());
}

}

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)

Answer 1

ApplicationContext参数中的以下更改可以解决此问题。

主要类

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());
}

Answer 2

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

如果你把@Component放在你的上面，这是没有必要的：

如果你想使用java配置，你必须将@Bean放在它上面：

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

编辑：检查Arun回答:-)

没有定义类型为[]的限定bean

2 个答案: