解决Spring的Component-scan和packagesToScan不支持Eclipse RCP问题

hehffyy 2013-04-24

展开全文

Spring 2.5开始，通过component-scan和packagesToScan设置，实现对jar包和class文件的package层级的自动扫描，从而利用Annotation实现零配置。

但在Eclipse RCP中，由于Eclipse的bundle原理，其bundle的jar包url为类似：bundleresource://269.fwk7214088/... ，而Spring对jar和class文件的scan却只支持file的protocol，即url必须是类似：file:/F:/eclipse/.... 所以在Eclipse RCP中集成SpringFramework，并在spring配置文件中使用component-scan和packagesToScan设置时，这两个配置失效，并抛出异常：

写道

2010-11-12 16:21:17,843 PathMatchingResourcePatternResolver WARN - Cannot search for matching files underneath URL [bundleresource://269.fwk7214088/com/abc/efg/] because it does not correspond to a directory in the file system
java.io.FileNotFoundException: URL [bundleresource://269.fwk7214088/com/abc/efg/] cannot be resolved to absolute file path because it does not reside in the file system: bundleresource://269.fwk7214088/com/abc/efg/
at org.springframework.util.ResourceUtils.getFile(ResourceUtils.java:204)
at org.springframework.core.io.AbstractFileResolvingResource.getFile(AbstractFileResolvingResource.java:51)
at org.springframework.core.io.UrlResource.getFile(UrlResource.java:168)
at org.springframework.core.io.support.PathMatchingResourcePatternResolver.doFindPathMatchingFileResources(PathMatchingResourcePatternResolver.java:530)
at org.springframework.core.io.support.PathMatchingResourcePatternResolver.findPathMatchingResources(PathMatchingResourcePatternResolver.java:351)
at org.springframework.core.io.support.PathMatchingResourcePatternResolver.getResources(PathMatchingResourcePatternResolver.java:269)
at org.springframework.context.support.AbstractApplicationContext.getResources(AbstractApplicationContext.java:1196)
at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:204)
at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:204)
at org.springframework.context.annotation.ComponentScanBeanDefinitionParser.parse(ComponentScanBeanDefinitionParser.java:84)
at org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(NamespaceHandlerSupport.java:73)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1335)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1325)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:136)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:93)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:493)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:212)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:126)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:92)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:130)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:465)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:395)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)

在网上Google无果的情况下，只好把目标放到了：

at org.springframework.util.ResourceUtils.getFile(ResourceUtils.java:204)

打开org.springframework.core-sources-3.0.1.RELEASE-A中的源码包，查看ResourceUtils.java:204，发现其代码如下：

Java代码  
if (!URL_PROTOCOL_FILE.equals(resourceUrl.getProtocol())) {  
    throw new FileNotFoundException(  
        description + " cannot be resolved to absolute file path " +  
        "because it does not reside in the file system: " + esourceUrl);  
}  

如果在这段代码前，可以把bundleresource类型的package转换为file类型的package，问题就可以解决。于是在这段代码前增加相关转换处理：

Java代码  
//Support Eclipse RCP bundle, Modify by Alex  
String protocol = resourceUrl.getProtocol();  
if(protocol.equals("bundleresource") || protocol.startsWith("bundle")) {  
    try {  
    resourceUrl = org.eclipse.core.runtime.Platform.resolve(resourceUrl);  
    } catch(IOException e) {  
        e.printStackTrace();  
    }  
}  
  
if (!URL_PROTOCOL_FILE.equals(resourceUrl.getProtocol())) {  
    throw new FileNotFoundException(  
            description + " cannot be resolved to absolute file path " +  
            "because it does not reside in the file system: " + resourceUrl);  
}  