转：解决 java.util.MissingResourceException: Can't find bundle for base name com...config, locale zh_CN 错误

转：解决java.util.MissingResourceException:Can'tfindbundleforbasenamecom...config,localezh_CN错误

Solvejava.util.MissingResourceException:Can'tfindbundleforbasenamecom...config,localezh_CN
atjava.util.ResourceBundle.throwMissingResourceException(ResourceBundle.java:836)
atjava.util.ResourceBundle.getBundleImpl(ResourceBundle.java:805)
atjava.util.ResourceBundle.getBundle(ResourceBundle.java:576)

Youknowjavaislookingforapropertiesfileinaspecificlocale.Youmaybebaffledwhyjavakeepscomplainingitcan'tfindapropertiesfilethatisrightthere.Afewthingstokeepinmindwhendebuggingthistypeoferrors:

Theseresourcepropertiesfilesareloadedbyclassloader,similartojavaclasses.Soyouneedtoincludetheminyourruntimeclasspath.

Theseresourceshavefully-qualified-resource-name,similartoafully-qualified-class-name,excerptyoucan'timportaresourceintoyourjavasourcefile.Why?becauseitsnametakestheformofastring.

ResourceBundle.getBundle("config")

tellstheclassloadertoloadaresourcenamed

"config"

withdefaultpackage(thatis,nopackage).ItdoesNOTmeanaresourceinthecurrentpackagethathasthereferencingclass.

ResourceBundle.getBundle("com.cheng.scrap.config")

tellstheclassloadertoloadaresourcenamed

"config"

withpackage

"com.cheng.scrap."

Itsfully-qualified-resource-nameis

"com.cheng.scrap.config"

Forinstance,youhaveaprojectlike

C:/ws/netbeans5/scrap>
|build.xml
+---build
|/---classes
|/---com
|/---cheng
|/---scrap
|Scrap.class
|
+---src
|/---com
|/---cheng
|/---scrap
|config.properties
|Scrap.java

Forthisstatementin

Scrap.java:ResourceBundleconfig=ResourceBundle.getBundle("config");

towork,youwillneedto

cpsrc/com/cheng/scrap/config.propertiesbuild/classes/

suchthat

config.properties

isdirectlyunder

classes

,andatthesamelevelas

com

.Alternatively,youcanput

config.properties

intoa

config.jar

suchthat

config.properties

isattherootof

config.jar

withoutanysubdirectories,andinclude

config.jar

intheclasspath.

Forthisstatementin

Scrap.java:ResourceBundleconfig=ResourceBundle.getBundle("com.cheng.scrap.config");

towork,youwillneedto

cpsrc/com/cheng/scrap/config.propertiesbuild/classes/

com/cheng/scrap/

suchthat

config.properties

isdirectlyunder

classes

/

com/cheng/scrap/

,andatthesamelevelas

scrap

.Alternatively,youcanput

com/cheng/scrap/

config.properties

(alongwiththelongsubdirectories)intoa

config.jar

,andincludeconfig.jarintheclasspath.[/code]

Youmaybewonderingwhyitismadesoconfusing?Thebenefitsaretwo-fold,asIseeit:

Locationtransparency.Atruntime,config.propertiesisNOTafile,it'sjustaaloadableresource.config.properitesmaynotexistinyourprojectatall,andthepersonwhowroteScrap.javamayhaveneverseenthisresource.AURLClassLoadercanfinditinanetworkpathorURLatruntime.Thisisespeciallyimportantforserver-sidecomponentssuchasEJB,Servlet,JSP,etc,whoarenormallynotallowedtoaccessfilesystems.Whenyouaskclassloadersforaresource,itsphysicallocationbecomesirrelevant.

Namespacemechanism.Havingapackageallowsmultiplepackagestohaveresourceswiththesameshortnamewithoutcausingconflicts.Thisisnodifferentfromjavapackagesandxmlnamespaces.