Java appengine devserver在第一次请求时重新部署应用程序

我正在使用maven构建google appengine应用程序。当客户端在第一个请求中访问应用程序时，devserver启动后，应用程序将重新部署，ServletListener将重新执行。在此过程中，servlet上下文丢失。我使用servlet上下文来存储连接的客户机列表。现在，由于应用程序已自动重新部署，并且servlet上下文已清除，因此我丢失了第一个客户端已连接的信息。servlet上下文确实存储所有后续连接的客户端，直到dev服务器停止

原因似乎是某个类文件是change，在devserver运行时不应更改

2013年6月25日上午6:31:31 com.google.appengine.tools.development.JettyContainerService$2文件更改 [信息]信息：文件已更改，正在重新加载web应用程序

以下是完整的日志

[INFO] 
[INFO] --- maven-war-plugin:2.1.1:war (default-war) @ NoteWebApp ---
[INFO] Packaging webapp
[INFO] Assembling webapp [NoteWebApp] in [/Users/saghosh/dev/NoteWebApp/target/NoteWebApp]
[INFO] Processing war project
[INFO] Copying webapp resources [/Users/saghosh/dev/NoteWebApp/src/main/webapp]
[INFO] Webapp assembled in [140 msecs]
[INFO] Building war: /Users/saghosh/dev/NoteWebApp/target/NoteWebApp.war
[INFO] WEB-INF/web.xml already added, skipping
[INFO] 
[INFO] <<< appengine-maven-plugin:1.8.1:devserver (default-cli) @ NoteWebApp <<<
[INFO] 
[INFO] --- appengine-maven-plugin:1.8.1:devserver (default-cli) @ NoteWebApp ---
[INFO] 
[INFO] Google App Engine Java SDK - Running Development Server
[INFO] 
[INFO] Retrieving Google App Engine Java SDK from Maven
[INFO] Running /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -XstartOnFirstThread -javaagent:/Users/saghosh/.m2/repository/com/google/appengine/appengine-java-sdk/1.8.1/appengine-java-sdk/appengine-java-sdk-1.8.1/lib/agent/appengine-agent.jar -Xbootclasspath/p:/Users/saghosh/.m2/repository/com/google/appengine/appengine-java-sdk/1.8.1/appengine-java-sdk/appengine-java-sdk-1.8.1/lib/override/appengine-dev-jdk-overrides.jar -Dappengine.fullscan.seconds=5 -classpath /Users/saghosh/.m2/repository/com/google/appengine/appengine-java-sdk/1.8.1/appengine-java-sdk/appengine-java-sdk-1.8.1/lib/appengine-tools-api.jar com.google.appengine.tools.development.DevAppServerMain --allow_remote_shutdown /Users/saghosh/dev/NoteWebApp/target/NoteWebApp
[INFO] 2013-06-25 12:01:16.813 java[15483:407] [Java CocoaComponent compatibility mode]: Enabled
[INFO] 2013-06-25 12:01:16.814 java[15483:407] [Java CocoaComponent compatibility mode]: Setting timeout for SWT to 0.100000
[INFO] Jun 25, 2013 12:01:18 PM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
[INFO] INFO: Successfully processed /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/appengine-web.xml
[INFO] 2013-06-25 12:01:18.717:INFO::Logging to STDERR via org.mortbay.log.StdErrLog
[INFO] Jun 25, 2013 12:01:18 PM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
[INFO] INFO: Successfully processed /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/web.xml
[INFO] 2013-06-25 12:01:18.978:INFO::jetty-6.1.x
[INFO] ****** Scan complete ******
[INFO] 2013-06-25 12:01:21.081:INFO::Started SelectChannelConnector@127.0.0.1:8080
[INFO] Jun 25, 2013 6:31:21 AM com.google.appengine.tools.development.JettyContainerService startHotDeployScanner
[INFO] INFO: Full scan of the web app in place every 5s.
[INFO] Jun 25, 2013 6:31:21 AM com.google.appengine.tools.development.AbstractServer startup
[INFO] INFO: Server default is running at http://localhost:8080/
[INFO] Jun 25, 2013 6:31:21 AM com.google.appengine.tools.development.AbstractServer startup
[INFO] INFO: The admin console is running at http://localhost:8080/_ah/admin
[INFO] Jun 25, 2013 6:31:21 AM com.google.appengine.tools.development.DevAppServerImpl start
[INFO] INFO: Dev App Server is now running
[INFO] Jun 25, 2013 6:31:27 AM com.google.appengine.api.datastore.dev.LocalDatastoreService init
[INFO] INFO: Local Datastore initialized: 
[INFO]  Type: Master/Slave
[INFO]  Storage: /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/appengine-generated/local_db.bin
[INFO] Jun 25, 2013 6:31:27 AM com.google.appengine.api.datastore.dev.LocalDatastoreService load
[INFO] INFO: The backing store, /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/appengine-generated/local_db.bin, does not exist. It will be created.
[INFO] Client trying to connect with ID 0354c90b-46cd-46d2-81d1-b57cd311a7a2Initialising client list
[INFO]  New client connected with ID  0354c90b-46cd-46d2-81d1-b57cd311a7a2
[INFO] Jun 25, 2013 6:31:31 AM com.google.appengine.tools.development.JettyContainerService$2 filesChanged
[INFO] INFO: A file has changed, reloading the web application.
[INFO] Jun 25, 2013 6:31:31 AM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
[INFO] INFO: Successfully processed /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/appengine-web.xml
[INFO] Jun 25, 2013 6:31:31 AM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
[INFO] INFO: Successfully processed /Users/saghosh/dev/NoteWebApp/target/NoteWebApp/WEB-INF/web.xml
[INFO] ****** Scan complete ******

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在谷歌搜索之后，我发现这是因为本地数据库文件是在第一次请求时创建的，目标目录被扫描以进行更改，导致应用程序重新加载

找到两个工作区

将db目录更改为外部目标目录。但如果其他任何更改，它将再次重新加载

-Dappengine.generated.dir=/tmp/blabla

2.禁用自动扫描，但作为开发人员，您希望避免每次更改代码时再次停止和启动服务器

<jvmFlags>
    <jvmFlag>-Dappengine.fullscan.seconds=-1</jvmFlag>
</jvmFlags>

-Dappengine.fullscan.seconds=-1

在谷歌解决这个问题之前，我仍然对一个永久性的解决方案持开放态度

<jvmFlags>
    <jvmFlag>-Dappengine.fullscan.seconds=-1</jvmFlag>
</jvmFlags>