Spring Boot应用在Eclipse外启动无法读取application.properties

本地用Eclipse（非STS）以普通Java应用启动Spring Boot 2.7.12项目完全正常，无额外JVM或应用参数。但通过Maven assembly插件构建fat jar后，执行java -jar myJar.jar启动时，Spring无法填充@Value注解，抛出配置占位符无法解析的异常。

报错信息 #

java -Xmx2g -jar myJar.jar
  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::               (v2.7.12)

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hsqlServer' defined in class path resource [org/pepito/myjar/config/SpringConfig.class]: Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'hsqldb.server.database' in value "${hsqldb.server.database}"
...
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'hsqldb.server.database' in value "${hsqldb.server.database}"
...

排查细节 #

• 配置项hsqldb.server.database已定义在默认的application.properties中，且该文件已正确打包到fat jar的classpath:/application.properties路径下
• 尝试添加启动参数--spring.config.location="classpath:application.properties"强制指定配置文件，问题依旧
• 开发环境：MacOS M2（Java 8），运行环境：32位Linux Mint 19（Java 8）

相关代码与配置 #

Maven构建配置 #

<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.7.12</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.9.0</version>
                <configuration>
                    <source>8</source>
                    <target>8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.1.1</version>
                <configuration>
                    <finalName>myJar</finalName>
                    <archive>
                        <manifest>
                            <mainClass>
                                org.pepito.myjar.SpringBootTgApplication
                            </mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <appendAssemblyId>false</appendAssemblyId>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

主类代码 #

@SpringBootApplication
public class SpringBootTgApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootTgApplication.class, args);
        try {
            new TelegramBotsApi(DefaultBotSession.class);
        } catch (TelegramApiException e) {
            throw new RuntimeException(e);
        }
    }
}

Bean配置类 #

@Configuration
@EnableAutoConfiguration
public class SpringConfig {

    @Bean(initMethod = "start", destroyMethod = "stop")
    public Server hsqlServer(@Value("${hsqldb.server.database}") String dbType,
            @Value("${hsqldb.server.dbname}") String dbName,
            @Value("${hsqldb.server.no_system_exit}") Boolean noSystemExit,
            @Value("${hsqldb.server.port}") Integer serverPort,
            @Value("${hsqldb.server.remote_open}") Boolean remoteOpen) throws IOException, AclFormatException {
        Server bean = new Server();
        HsqlProperties props = new HsqlProperties();
        props.setProperty("server.database.0", dbType);
        props.setProperty("server.dbname.0", dbName);
        props.setProperty("server.no_system_exit", noSystemExit);
        props.setProperty("server.port", serverPort);
        props.setProperty("server.remote_open", remoteOpen);
        bean.setProperties(props);
        return bean;
    }

    @Bean
    @DependsOn("hsqlServer")
    public DataSource getDataSource(@Value("${hsqldb.datasource.driver-class-name}") String driverClassName,
            @Value("${hsqldb.datasource.url}") String url, @Value("${hsqldb.datasource.username}") String username,
            @Value("${hsqldb.datasource.password}") String password) {
        DataSourceBuilder<?> dataSourceBuilder = DataSourceBuilder.create();
        dataSourceBuilder.driverClassName(driverClassName);
        dataSourceBuilder.url(url);
        dataSourceBuilder.username(username);
        dataSourceBuilder.password(password);
        return dataSourceBuilder.build();
    }
}

application.properties内容 #

server.port=28000
BOT_TOKEN=<token>
BOT_NAME=<value>
CCAA=<value>

hsqldb.server.database=file:<file>
hsqldb.server.dbname=<db name>
hsqldb.server.no_system_exit=true
hsqldb.server.port=9001
hsqldb.server.remote_open=true
hsqldb.datasource.driver-class-name=org.hsqldb.jdbc.JDBCDriver
hsqldb.datasource.url=jdbc:hsqldb:hsql://localhost/<db name>
hsqldb.datasource.username=<user>
hsqldb.datasource.password=<pass>

spring.jpa.database-platform=org.hibernate.dialect.HSQLDialect
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update

logging.level.root=INFO
logging.level.org.pepito=TRACE

问题更新 #

改用Maven shade插件构建fat jar后，应用可正常启动，@Value注解能正确解析配置项，推测问题根源在于assembly插件与Spring Boot的fat jar构建逻辑不兼容。

内容的提问来源于stack exchange，提问作者Cheloute