我创建了一个jar文件，其中包含一个由Spring服务包装的Ruby gem（activemerchant），它使用JRuby ScriptContainer调用一个利用ruby gem的小Ruby脚本。对于这个jar的单元测试都可以正常使用Ruby gem - 宝石被拾取并按预期运行。
jar包含以下文件夹：
com
... <not relevant> ...
gateways
... <not relevant> ...
gems
activemerchant-1.75.0
activesupport-5.2.0.beta2
builder-3.2.3
concurrent-ruby-1.0.5-java
i18n-0.9.1
minitest-5.11.1
nokogiri-1.8.1-java
thread_safe-0.3.6-java
tzinfo-1.2.4
META-INF
MANIFEST.MF
scripts
main.rb
specifications
activemerchant-1.75.0.gemspec
activesupport-5.2.0.beta2.gemspec
builder-3.2.3.gemspec
concurrent-ruby-1.0.5-java.gemspec
i18n-0.9.1.gemspec
minitest-5.11.1.gemspec
nokogiri-1.8.1-java.gemspec
thread_safe-0.3.6-java.gemspec
tzinfo-1.2.4.gemspec
jar嵌入到使用嵌入式Tomcat容器的Spring Boot应用程序中。在启动Spring Boot应用程序时，我收到错误：
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'activeMerchantGatewayProvider': Invocation of init method failed; nested exception is org.jruby.embed.EvalFailedException: (LoadError) no such file to load -- activemerchant
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:408)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1570)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:220)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:353)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:334)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1088)
at com.mydomain.financial.gateway.GatewayService.lambda$init$0(GatewayService.java:39)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
at com.mydomain.financial.gateway.GatewayService.init(GatewayService.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:365)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:310)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:133)
... 81 common frames omitted
Caused by: org.jruby.embed.EvalFailedException: (LoadError) no such file to load -- activemerchant
at org.jruby.embed.internal.EmbedEvalUnitImpl.run(EmbedEvalUnitImpl.java:131)
at org.jruby.embed.ScriptingContainer.runUnit(ScriptingContainer.java:1307)
at org.jruby.embed.ScriptingContainer.runScriptlet(ScriptingContainer.java:1352)
at com.mydomain.financial.gateway.activemerchant.ActiveMerchantGatewayProvider.init(ActiveMerchantGatewayProvider.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:365)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:310)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:133)
... 108 common frames omitted
Caused by: org.jruby.exceptions.RaiseException: (LoadError) no such file to load -- activemerchant
at org.jruby.RubyKernel.require(org/jruby/RubyKernel.java:955)
at uri_3a_classloader_3a_.META_minus_INF.jruby_dot_home.lib.ruby.stdlib.rubygems.core_ext.kernel_require.require(uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:55)
at RUBY.<main>(classpath:/scripts/main.rb:2)
如何让Spring Boot嵌入式Tomcat / JRuby识别嵌入式jar中的宝石？
答案 0 :(得分：0)
什么是PITA。我找到了一个工作，但需要花费一些力气。
失败的原因是JRuby无法扫描内部jar文件中的宝石。而这似乎是Java的问题，而不是JRuby的问题。我也无法找到一种方法来扫描jar中jar的目录，尽管我可以从jar中的jar中获取文件。我的解决方案是在Spring jar应用程序启动期间在内部jar中创建一个gems列表并检索该列表文件。
具体做法是：
在内部jar中，我更改了ScriptContainer逻辑，如下所示（GEMS_PATH = / gems）：
@PostConstruct
private void init() {
ScriptingContainer scriptingContainer = new ScriptingContainer(LocalContextScope.CONCURRENT);
// Locate load paths and add them to the container. This doesn't work in JRuby as expected
// once this jar is embedded into a Spring Boot uber project, so I need to do it explicitly
// here.
List<String> loadPaths = scriptingContainer.getLoadPaths();
URL resource = getClass().getResource(GEMS_PATH + "/gems.list");
if (resource == null) {
throw new RuntimeException("Unable to find " + GEMS_PATH + "/gems.list");
}
try {
log.debug("ActiveMerchant gems root: {}", resource);
String content = IOUtils.toString(resource, "UTF-8");
if (StringUtils.isEmpty(content)) {
throw new RuntimeException(GEMS_PATH + "/gems.list is empty");
}
Stream.of(content.split(";")).forEach(gem -> {
String gemDir = "uri:classloader:" + GEMS_PATH + "/" + gem + "/lib";
if (!loadPaths.contains(gemDir)) {
loadPaths.add(gemDir);
log.debug("ActiveMerchant added gem entry to load paths: {}", gemDir);
}
});
} catch (IOException e) {
throw new RuntimeException(e);
}
正如您所看到的，这是内部jar中Spring管理组件的一部分。
在它的pom.xml中，我添加了这个插件：
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.8</version>
<executions>
<execution>
<phase>prepare-package</phase>
<configuration>
<target>
<dirset id="gems-dir" dir="${project.build.outputDirectory}/gems" includes="*"/>
<property name="gem-dirs" refid="gems-dir"/>
<echo file="${project.build.outputDirectory}/gems/gems.list">${gem-dirs}</echo>
</target>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
这将在内部jar中创建文件/gems/gems.list，其中包含打包到jar中的所有gem。当Spring Boot初始化组件时，它会找到gems.list并使用它来构建加载路径列表。