java - Spring boot maven多模块项目：编译失败找不到符号

Question

我创建了一个带有父 pom 的多模块 spring boot 项目。在模块测试数据中，我添加了一些实体类用户和登录：

@Table
@Entity
public class Login implements Serializable {
    ... another column
    @Column(unique = true, columnDefinition = "VARCHAR(50)", nullable = false)
    private String username;
    @JsonIgnore
    @OneToOne(mappedBy = "login")
    private User user;
    // getter and setter

用户类：

@Table
@Entity
public class User implements Serializable{
...
    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(referencedColumnName = "login_id")
    private Login login;
...

模块test-data的pom.xml：

 <parent>
        <groupId>com.emo.test</groupId>
        <artifactId>emo-parent</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath/>
    </parent>

    <artifactId>test-data</artifactId>
    <version>0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <description>Demo project for Spring Boot</description>

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        // other dependencies
    </dependencies>

测试数据的主要类别：

package com.test;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class TestApplication {

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

test-oauth的主要类：

package com.oauth.server;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class OAuthApplication {

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

我在第二个模块 test-oauth 中添加了模块 test-data 作为依赖项，如下所示：

<modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>com.emo.test</groupId>
        <artifactId>emo-parent</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath/>
    </parent>

    <artifactId>test-oauth</artifactId>
    <version>0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>test-oauth</name>
    <url>http://maven.apache.org</url>

    <dependencies>
        <dependency>
            <groupId>com.emo.test</groupId>
            <artifactId>test-data</artifactId>
            <version>0.1-SNAPSHOT</version>
            <exclusions>
                <exclusion>
                    <groupId>org.liquibase</groupId>
                    <artifactId>liquibase-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

进入模块 test-oauth，我使用实体用户：

@Transactional
@Service("userServiceImpl")
public class UserServiceImpl {

    @PersistenceContext
    private EntityManager entityManager;

    public User findByUsername(String username) throws EmptyResultDataAccessException {
        String query = "FROM Login l WHERE l.username = :username";
        final Login l = (Login) entityManager.createQuery(query).setParameter("username", username).getSingleResult();
        return l.getUser();
    }
}

我得到了这个例外：Compilation failure: Compilation failure: cannot find symbol User, package com.test.core.entities does not exist

我的父母 pom.xml

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.emo.test</groupId>
    <artifactId>emo-parent</artifactId>
    <version>0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <modules>
        <module>test-data</module>
        <module>test-oauth</module>
    </modules>

    <properties>
        <java.version>1.11</java.version>
        <oauth.version>2.2.2.RELEASE</oauth.version>
        <kazi.data.version>0.1-SNAPSHOT</kazi.data.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.security.oauth</groupId>
            <artifactId>spring-security-oauth2</artifactId>
            <version>${oauth.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <verbose>true</verbose>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>spring-plugin-releases</id>
            <url>https://repo.spring.io/plugins-release</url>
        </pluginRepository>
    </pluginRepositories>