Maven Multi Module坚持在业务模块中复制数据源Application.Properties

Question

我有spring boot maven java多模块结构。我的结构是：

product (parent pom module)
..product-data (child pom module)
..product-business (has dependency for product-data) 
..product-rest (has dependency for product-business) 
..product-entities (child pom module)

product-data将实体对象返回到product-business，product-business将实体对象返回到product-rest，product-rest返回json对象。

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.owner</groupId>
    <artifactId>product</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <nopeasti.version>1.0.0-SNAPSHOT</nopeasti.version>
    </properties>

    <dependencies>

    </dependencies>

    <modules>
        <module>product-data</module>
        <module>product-business</module>
        <module>product-rest</module>
        <module>product-entities</module>
    </modules>
</project>

<project>
    <artifactId>product-data</artifactId>
    <packaging>jar</packaging>
    <parent>
        <groupId>com.owner</groupId>
        <artifactId>product</artifactId>
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>
    <dependencyManagement>
         <dependencies>
            <dependency>
                <!-- Import dependency management from Spring Boot -->
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>1.5.8.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.0.0.M6</version>
            </plugin>
        </plugins>
    </build>
</project>

产品-业务POM

<project>
    <artifactId>product-business</artifactId>
    <packaging>jar</packaging>
    <parent>
        <groupId>com.owner</groupId>
        <artifactId>product</artifactId>
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>
    <dependencyManagement>
         <dependencies>
            <dependency>
                <!-- Import dependency management from Spring Boot -->
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>1.5.8.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.owner</groupId>
            <artifactId>product-data</artifactId>
            <scope>compile</scope>
            <version>1.0.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.0.0.M6</version>
            </plugin>
        </plugins>
    </build>
</project>

Answer 1

据此，

不建议将application.properties放在库中，因为使用它的应用程序在运行时可能会发生冲突（只从类路径加载一个application.properties）

为了解决这个问题并保持解耦的体系结构，我在product-data模块的resources文件夹下创建了另一个文件data.properties，并在配置文件中指定了@PropertySource注释。下面是product-data模块的配置文件。Spring.DataSource属性是在该文件中定义的。然后在其他2个模块中就不需要Spring.DataSource属性了。

@ComponentScan
@EnableAutoConfiguration
@SpringBootConfiguration
@PropertySource(value = "data.properties")
public class NopeastiDataConfig {
    // no main needed here as this is library consumed by business layer
}

请进一步阅读：外部化配置