Question

我有一个父母类Car＆amp;子类Axio。所以，我试图通过子构造函数中的super（“Axio”）将参数传递给父类中的构造函数参数，然后将该值分配给父类中定义的属性。当我尝试在spring boot中执行应用程序时，它会抛出一个异常陈述

Description:

Field car in com.test.efshop.controller.HelloController required a bean of type 'com.test.efshop.Axio' that could not be found.


Action:

Consider defining a bean of type 'com.test.efshop.Axio' in your configuration.

任何人都可以告诉我如何在春季靴子中实现这一目标？我的代码如下，

// Car class

package com.test.efshop;

public class Car {

private String carName;

public String getCarName() {
    return carName;
}

public void setCarName(String carName) {
    this.carName = carName;
}

public Car(String carName) {
    this.carName = carName;
}

public String print() {
    return "Car name is : "+carName;    
}
}

//作为Axio的汽车类的子类

  package com.test.efshop;

    public class Axio extends Car{

    public Axio() {
        super("Axio");
    }   
    }

//主要方法

package com.test.efshop;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.servlet.ViewResolver;

import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@SpringBootApplication
public class DemoApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

//控制器类

package com.test.efshop.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import com.test.efshop.Axio;
import com.test.efshop.Engine;

@Controller
public class HelloController {

    @Autowired
    private Axio car;

    @RequestMapping(value = "/hello")
    public ModelAndView print() {
        return new ModelAndView("index");
    }
    //This is the method which i used to return the value of Car class
    @RequestMapping(value = "/hello2")
    @ResponseBody
    public String print2() {
        return car.print();
    }


}

Answer 1

正如pvpkiran所评论的那样，如果一个类不是一个Spring bean，你就不能@Autowire。

选项a）您将Axio类转换为服务或组件。

@Component
public class Axio extends Car {
    public Axio() {
        super("Axio");
    }   
}

选项b）定义类型为Axio的bean。

@SpringBootApplication
public class DemoApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Bean
    public Axio myAxioBean() {
        return new Axio();
    }

}

如何在启用componentscan时通过子类构造函数注入父原始类型属性

1 个答案: