昨天用spring做了個定時器，用於定時掃描某通訊公司外網ftp伺服器的約定路徑下是否有我需要的檔案並下載到本公司伺服器上。記得以前做過類似的一個定時器，覺得手到擒來的事情，沒想到又折騰了大半天，就是因為spring中commons-attributes-compiler.jar的使用問題。
   問題是這樣的：掃面和下載程式，觸發類和函式，web.xml和spring配置檔案，這些準備工作都已經完成，就是在伺服器啟動的時候報錯：

INFO: Deploying web application archive GRCC.war 
Sep 14, 2007 13:22:18 AM org.apache.catalina.util.ExtensionValidator validateManifestResources 
INFO: ExtensionValidator[/GRCC][commons-attributes-api.jar]: Required extension “ant” not found. 
Sep 14, 2007 13:22:18 AM org.apache.catalina.util.ExtensionValidator validateManifestResources 
INFO: ExtensionValidator[/GRCC][commons-attributes-compiler.jar]: Required extension “ant” not found. 
Sep 14, 2007 13:22:18 AM org.apache.catalina.util.ExtensionValidator validateManifestResources 
INFO: ExtensionValidator[/GRCC][commons-attributes-compiler.jar]: Required extension “javadoc” not found. 
Sep 14, 2007 13:22:18 AM org.apache.catalina.util.ExtensionValidator validateManifestResources 
INFO: ExtensionValidator[/GRCC]: Failure to find 3 required extension(s). 
   Sep 14, 2007 13:22:18 AM org.apache.catalina.core.StandardContext start 
SEVERE: Error getConfigured 
Sep 14, 2007 13:22:18 AM org.apache.catalina.core.StandardContext start 
SEVERE: Context [/GRCC startup failed due to previous errors 
Sep 14, 2007 13:22:18 AM org.apache.catalina.core.StandardContext stop 
INFO: Container org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/GRCC] has not been started

並導致本專案無法啟動！
    從錯誤可以看出，commons-attributes-compiler.jar需要的”ant”,”javadoc”,”qdox”無法找到，我又檢查了數遍，ant和qdox這些jar包我都已經加lib裡了，可spring就是視而不見！我鬱悶了好久，最後實在不行了，我決定解壓commons-attributes-compiler.jar，看看它的廬山真面目，裡面還真不復雜：META-INFMANIFEST.MF,compileorgapachecommonsattributesanttasks.properties,LICENSE.txt,,
NOTICE.txt,後兩個肯定是說明性的檔案，我沒有理會；第二個是屬性檔案，我看格式和註釋都沒有什麼不妥；就MANIFEST.MF裡面內容較多，並且有異常之處(我標出了):

Manifest-Version: 1.0
Ant-Version: Apache Ant 1.5.3 
Created-By: Apache Maven
Built-By: hen
Package: org.apache.commons.attributes.compiler
Build-Jdk: 1.4.2_05
Extension-Name: commons-attributes-compiler
Specification-Title: Attribute Compiler
Specification-Vendor: The Apache Software Foundation
Implementation-Title: org.apache.commons.attributes.compiler
Implementation-Vendor: The Apache Software Foundation
Implementation-Version: 2.2
Extension-List: ant qdox commons-attributes-api javadoc
ant-Extension-Name: ant
ant-Implementation-Version: 1.5
ant-Implementation-URL: http://www.ibiblio.org/maven/ant/jars/ant-1.
5.jar
qdox-Extension-Name: qdox
qdox-Implementation-Version: 1.5
qdox-Implementation-URL: http://www.ibiblio.org/maven/qdox/jars/qdox-1.
5.jar
commons-attributes-api-Extension-Name: commons-attributes-api
commons-attributes-api-Implementation-Version: 2.2
commons-attributes-api-Implementation-URL: http://www.ibiblio.org/maven/commons-attributes/jars/commons-attributes-api-2.2
.jar
javadoc-Extension-Name: javadoc
javadoc-Implementation-Version: 1.4
javadoc-Implementation-URL: http://www.ibiblio.org/maven/javadoc/jars/javadoc-1.4
.jar
Implementation-Vendor-Id: org.apache
X-Compile-Source-JDK: 1.4
X-Compile-Target-JDK: 1.4


這裡的URL後面的值被換行符隔開了，顯然，如果讓我們自己，是不會這麼幹的。於是，做修改如下：

Manifest-Version: 1.0
Ant-Version: Apache Ant 1.5.3 
Created-By: Apache Maven
Built-By: hen
Package: org.apache.commons.attributes.compiler
Build-Jdk: 1.4.2_05
Extension-Name: commons-attributes-compiler
Specification-Title: Attribute Compiler
Specification-Vendor: The Apache Software Foundation
Implementation-Title: org.apache.commons.attributes.compiler
Implementation-Vendor: The Apache Software Foundation
Implementation-Version: 2.2
Extension-List: ant qdox commons-attributes-api javadoc
ant-Extension-Name: ant
ant-Implementation-Version: 1.5
ant-Implementation-URL: http://www.ibiblio.org/maven/ant/jars/ant-1.5.jar
qdox-Extension-Name: qdox
qdox-Implementation-Version: 1.5
qdox-Implementation-URL: http://www.ibiblio.org/maven/qdox/jars/qdox-1.5.jar
commons-attributes-api-Extension-Name: commons-attributes-api
commons-attributes-api-Implementation-Version: 2.2
commons-attributes-api-Implementation-URL: http://www.ibiblio.org/maven/commons-attributes/jars/commons-attributes-api-2.2.jar
javadoc-Extension-Name: javadoc
javadoc-Implementation-Version: 1.4
javadoc-Implementation-URL: http://www.ibiblio.org/maven/javadoc/jars/javadoc-1.4.jar
Implementation-Vendor-Id: org.apache
X-Compile-Source-JDK: 1.4
X-Compile-Target-JDK: 1.4


重新打成jar包，新增到專案lib中，啟動執行，一切OK！

     可是，以前寫定時器也沒遇到這種情況啊，我想這跟spring的版本有關係吧；今天用的spring2.0，可是誰把MANIFEST.MF中的URL弄錯的呢？我想不應該是官方的bug吧，可能是我不是在官網上下的spring開發包，有機會看看官網上是否也是這個樣子。不管怎麼說，專案還是在波瀾不驚中順利進行。。。