无法在 Spring Boot 项目中使用自定义 jar

Question

我正在尝试将 Spring Boot 应用程序的一项服务用于另一个 Spring Boot 服务。由于一些限制，我必须使用基于 jar 的方法，即，我正在使用命令 ma​​ven build 构建第一个项目，并使用为该项目创建的 jar。

我正在将该 jar 添加到其他/依赖项目的构建路径中。但是我看不到我的主要项目的服务。我也无法自动装配它们。几天前，不知何故，我能够看到服务，但依赖项目的 maven 构建失败，因为它无法在依赖项目中找到自动装配服务的源包（一个明显的失败，因为该包在主项目中）。我已经尝试了很多事情，但我不知道现在如何进行。

主项目

JartestApplication.java

@SpringBootApplication
public class JartestApplication 
{

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

}

Service.java

@FunctionalInterface
public interface DbService 
{
    public BigInteger getRowCount(String tableName) throws Exception;
}

ServiceImpl.java

@Service
public class DbServiceImpl implements DbService
{

    @Autowired
    EntityManager em;

    @Override
    public BigInteger getRowCount(String tableName) throws Exception
    {
        return (BigInteger) em.createNativeQuery("select count(*) from "+tableName).getSingleResult();
    }

}

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 https://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>2.1.8.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>jartest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>jartest</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

    </dependencies>

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

</project>

依赖项目

ImportjartestApplication.java

@SpringBootApplication
public class ImportjartestApplication 
{

    public static void main(String[] args)
    {
        ApplicationContext context = SpringApplication.run(ImportjartestApplication.class, args);
        Test test = context.getBean(Test.class);
        System.err.println(test.check("test"));
    }

}

Test.java

@FunctionalInterface
public interface Test 
{
    public BigInteger check(String name);
}

TestImpl.java

@Service
public class TestImpl implements Test 
{

    //@Autowired    ---  what i want  to do
    //DbService service;    --- service is not visible even after i have added the jar of main project into the build path of this project

    @Override
    public BigInteger check(String name) 
    {
        return null;
        //return service.getRowCount(name);  -- my actual aim
    }

}

有没有其他方法可以在不共享代码的情况下共享我的服务？

由于某些限制，我无法将我的服务公开为休息服务，因此我尝试将主服务部署为 jar 并将其添加到依赖项目的构建路径中。

Answer 1

在您的spring-boot-maven-plugin 中添加以下条目。

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <!--- begins --->
  <configuration>
    <includeSystemScope>true</includeSystemScope>
  </configuration>
  <!--- ends --->
</plugin>

Answer 2

after lots of debugging and reading the docs i found the solution and hereby i'm posting the steps to it....

1. Used the below build configuration in source project

    <build>
        <finalName>generator</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <configuration>
                            <classifier>exec</classifier>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

2. Included the dependency into target project as system scope 

        <dependency>
            <groupId>generator</groupId>
            <artifactId>generator</artifactId>
            <scope>system</scope>
            <version>1.0</version>
            <systemPath>${project.basedir}\src\lib\generator.jar
            </systemPath>
        </dependency>

3. Included the following build configuration in target project


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <!--- begins - -->
                <configuration>
                    <includeSystemScope>true</includeSystemScope>
                </configuration>
                <!--- ends - -->
            </plugin>
        </plugins>
    </build>

4. Used component scan at root level in target class

@SpringBootApplication
@ComponentScan("com.example.jar.service")
public class JartestApplication 
{
    public static void main(String[] args) throws IOException 
    {
          System.out.println("Hello world");
    }
}