未找到包（多模块 spring 项目）

Question

未找到包（多模块 spring 项目）

Leo*_*dro 9 java spring maven

我使用Spring Initializr创建了两个模块：

api（即 Spring Web）

db（这是 Spring Data MongoDB）

我把它们放在同一个项目中，在某种程度上它们现在是子模块。

在创建测试之前，我可以mvn clean install使用 BUILD SUCCESS 消息。没有问题。

但是，如果我尝试创建一个测试（或者甚至在主结构中的控制器中使用它），它使用db模块存储库类从 MongoDB 获取数据，mvn clean install将指责包不存在，尽管 IntelliJ 可以识别和索引它和文件存在。

结构是：

api
\- src/main/java
  \- com.example.api.controllers
    \- UserController.java
\- src/test/java
  \- com.example.api.controllers
    \- UserControllerTest.java
db
\- src/main/java
  \- com.example.db.repositories
    \- UserRepository.java
model
\- src/main/java
  \- com.example.model
    \- User.java

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应用程序.java

package com.example.api;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@SpringBootApplication
public class ApiApplication {

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

}

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用户控制器.java

package com.example.api.controllers;

import com.example.api.Constants;
import com.example.db.repositories.UserRepository;
import com.example.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Autowired
    private UserRepository userRepository;

    @GetMapping(Constants.V1 + "user")
    public User getUser() {
        User user = new User("John");
        userRepository.save(user);
        return user;
    }
}

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现在，如果我运行mvn clean install，我将收到 Maven 错误提示package com.example.db.repositories does not exist。

模块db是模块api 中的一个依赖项，并且api模块设置为在父 pom 中的db之后编译。

父级 - pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <modules>
        <module>model</module>
        <module>db</module>
        <module>api</module>
    </modules>

</project>

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数据库 - pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath/>
    </parent>

    <groupId>com.example</groupId>
    <artifactId>db</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>model</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>

</project>

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api - pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>LATEST</version>
        <relativePath/>
    </parent>

    <groupId>com.example</groupId>
    <artifactId>api</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>db</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

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如何让 maven 看到这个包？

找到包后出现新错误

2019-01-14 19:16:55.060  WARN 31104 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.example.db.repositories.UserRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
2019-01-14 19:16:55.066  INFO 31104 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2019-01-14 19:16:55.087  INFO 31104 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-01-14 19:16:55.224 ERROR 31104 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Field userRepository in com.example.api.controllers.UserController required a bean of type 'com.example.db.repositories.UserRepository' that could not be found.

The injection point has the following annotations:
        - @org.springframework.beans.factory.annotation.Autowired(required=true)


Action:

Consider defining a bean of type 'com.example.db.repositories.UserRepository' in your configuration.

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Answer 1

小智 7

您可以db使用以下方法（重新）打包为 Spring boot“应用程序”而不是库spring-boot-maven-plugin：

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <executions>
    <execution>
      <goals>
        <goal>repackage</goal>
      </goals>
    </execution>
  </executions>
</plugin>

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该 jar 被重新打包，从而将com.example.db.repositories包（及其类）添加到 BOOT-INF 文件夹中。这会导致编译失败。

<plugin>..</plugin>只需从中删除该部件即可db/pom.xml。这将创建一个可以在api模块中导入的常规 jar。

注意：我假设api有该类Main并将打包为启动应用程序。

Answer 2

ths*_*hst 6

Springboot 自动发现只会从您的配置类开始下降。您的申请位于

\n\n

com.example.api\n

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但回购协议位于

\n\n

com.example.db\n

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也可以添加搜索路径到 autodiscover .db 或将应用程序类移动到 com.example 或将 db 代码移动到 com.example.api

\n\n

选项1

\n\n

@ComponentScan(\xe2\x80\x9ccom.example\xe2\x80\x9d)\n@SpringBootApplication\npublic class ExampleApplication  {\n

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选项2

\n\n

@ComponentScan({"com.example.api","com.example.db"})\n@SpringBootApplication\npublic class ExampleApplication {\n

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您还可以将 scanBasePackages 属性添加到 SpringbootApplication 注解中以获得相同的效果。

\n\n

@SpringBootApplication(scanBasePackages= {"com.example.api","com.example.db"})\npublic class ExampleApplication {\n

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请参阅此处的文档https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/autoconfigure/SpringBootApplication.html#scanBasePackages--

\n

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