@Autowired 不起作用，我们不知道原因。服务和控制器位于不同的模块和包中，但我们认为这并不重要。我们可以手动实例化服务，这样控制器模块就能够“看到”公共模块。

运行该应用程序会导致以下错误：

Parameter 0 of constructor in com.xx.campaign_api.controller.MyController required a bean of type 'com.xx.campaign.common.service.MyService' that could not be found.

我们有一个多模块 spring boot 3.4.2 项目，其 pom 如下：

<project xxx
    <groupId>org.springframework</groupId>
    <artifactId>our-service</artifactId>
    <version>0.1.0</version>
    <packaging>pom</packaging>

    <modules>
        <module>campaign-common</module>
        <module>campaign-api</module>
        <module>campaign-schedule</module>
    </modules>
</project>

在 api 模块中我们有一个像这样的休息控制器：

package com.xx.campaign_api.controller;
import com.xx.campaign.common.service.MyService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyController {

    private MyService testService;

    @Autowired
    public MyController(MyService testService) {  // THIS LINE IS FAILING
        this.testService = testService;
    }

    @GetMapping("/test")
    public String test() {
    return testService.test();
    }
}

该服务如下所示：

package com.xxx.campaign.common.service;
import org.springframework.stereotype.Service;

@Service
public class MyServiceImpl implements MyService {
    @Override
    public String test() {
        return "test3";
    }
}

package com.xxx.campaign.common.service;
public interface MyService {
    public String test();
}

主要类如下所示：

package com.xx.campaign_api;
@SpringBootApplication
public class CampaignApiApplication {
    public static void main(String[] args) {
        SpringApplication.run(CampaignApiApplication.class, args);
    }
}

在控制器模块的 pom 中，我们有：

    <dependency>
        <groupId>xx</groupId>
        <artifactId>campaign-common</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <scope>compile</scope>
    </dependency>

我也尝试过这个：

package com.xx.campaign_api.controller
@SpringBootApplication(scanBasePackages = "com.xx")
@RestController
public class GaController {

    private MyService myService;

    @Autowired
    public GaController(MyService myService) {  // THIS LINE IS FAILING
        this.myService = myService;
    }

但该应用程序无法启动并出现以下错误：

Web application could not be started as there was no org.springframework.boot.web.servlet.server.ServletWebServerFactory bean defined in the context.