SpringBoot: Can I @Autowire Bean in runnable JAR from JAR provided using java -cp?

Question

I have runnable JAR A which contains interface:

interface FooInterface {
    void foo();
    ...
}

In JAR AI have also class which is trying to autowire FooInterface implmenetation:

class Other{
    @Autowired 
    FooInterface fooInterfaceImplementation;
    ...
}

In other project BI have jar A as external library and implementation of the FooInterface:

@Component
class BarClass implements FooInterface {
    void foo(){...}
    ...
}

I'm trying to run my runnable A JAR with classes from JAR B by using command:

java -jar A.jar -cp B.jar

But it ends with following exception:

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.ocado.cfc.optimisation.AlgorithmInterface' available
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:348)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:335)
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1093)
        at com.ocado.cfc.optimisation.Executable.main(Executable.java:81)

Is it possible to autowire required bean in that way?

Any help highly appreciated.

Answer 1

是的，为了让Spring从类路径JAR文件中检测/扫描bean，您需要使用类级别注释@ComponentScan(basePackages="com.ocado")将包添加到spring boot启动器类中。

Answer 2

It isn't possible if you try to use -jar and -cp together. -cp is ignored when you use -jar .

If you want to have more than one jar on the classpath you can pass them both in using -cp . You'll then have to also provide the name of the main class that you want to launch. Given that you appear to be using Spring Boot, that might look like this:

java -cp A.jar:B.jar org.springframework.boot.loader.JarLauncher

You may also be interested in Spring Boot's PropertiesLauncher that allows you to create an executable jar with a configurable class path.