未找到包（多模块弹簧项目）

java maven spring

2022-09-04 21:05:29

我使用Spring Initializr创建了两个模块：

api （这是Spring Web）

db（即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，我可以使用“生成成功”消息。没有问题。mvn clean install

但是，如果我尝试创建一个测试（甚至在主结构内的控制器中使用它），其中它使用db模块存储库类，从MongoDB获取数据，将指责包不存在，尽管IntelliJ可以识别和索引它并且文件存在。mvn clean install

结构为：

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

ApiApplication.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);
    }

}

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;
    }
}

现在，如果我运行，我会收到maven错误说。mvn clean installpackage com.example.db.repositories does not exist

模块 db 是模块 api 中的依赖项，api 模块设置为在父级 pom 中的 db 之后编译。

父 - 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>

db - 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>

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>

如何让专家看到这个包？

找到包后的新错误

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.

答案 1

您正在（重新）打包为Spring引导“应用程序”而不是库，方法是使用：dbspring-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>

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

只需从中移除部件即可。这将创建一个可以在模块中导入的常规jar。<plugin>..</plugin>db/pom.xmlapi

注意：我假设它具有该类，并将打包为引导应用程序。apiMain

答案 2

Springboot 自动发现将仅从您的配置类向下下降。您的应用程序位于

com.example.api

但存储库位于

com.example.db

将搜索路径添加到自动发现.db，或者将应用程序类移动到 com.example 或将数据库代码移动到 com.example.api

备选案文1

@ComponentScan(“com.example”)
@SpringBootApplication
public class ExampleApplication  {

备选案文2

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

您还可以将 scanBasePackages 属性添加到 SpringbootApplication 注释中，以获得相同的效果。

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

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