警告：无法从类加载器层次结构中扫描 <>.jar。 FileNotFoundException

Question

所以我有我的项目： https://github.com/Leejjon/Blindpool

当我尝试从 IntelliJ 中的 Google App Engine 部署运行配置将其发布到应用引擎时，它可以完美运行并且部署也很好。

但我收到了很多警告（这只是一个）：

Deploying '[2017-07-27 23:15:04] Maven build: Blindpool. Project: blindepoule. Version: 6'...
Created temporary staging directory: C:\Users\Leejjon\AppData\Local\Temp\gae-staging-blindepoule684
Reading application configuration data...
jul 27, 2017 11:15:06 PM com.google.apphosting.utils.config.IndexesXmlReader readConfigXml
INFO: Successfully processed C:\Users\Leejjon\IdeaProjects\Blindpool\target\blindpool-1.0-SNAPSHOT\WEB-INF\appengine-generated\datastore-indexes-auto.xml


Beginning interaction for module default...
0% Scanning for jsp files.
0% Compiling jsp files.
jul 27, 2017 11:15:07 PM org.apache.tomcat.util.scan.StandardJarScanner scan
WARNING: Failed to scan [file:/C:/Users/Leejjon/AppData/Local/Google/Cloud%2520SDK/google-cloud-sdk/platform/google_appengine/google/appengine/tools/java/lib/impl/appengine-api-labs.jar] from classloader hierarchy
java.io.FileNotFoundException: C:\Users\Leejjon\AppData\Local\Google\Cloud%20SDK\google-cloud-sdk\platform\google_appengine\google\appengine\tools\java\lib\impl\appengine-api-labs.jar (The system cannot find the path specified)
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(ZipFile.java:219)
at java.util.zip.ZipFile.<init>(ZipFile.java:149)
at java.util.jar.JarFile.<init>(JarFile.java:166)
at java.util.jar.JarFile.<init>(JarFile.java:103)
at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:93)
at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:69)
at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:109)
at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
at org.apache.tomcat.util.scan.JarFileUrlJar.<init>(JarFileUrlJar.java:47)
at org.apache.tomcat.util.scan.JarFactory.newInstance(JarFactory.java:36)
at org.apache.jasper.servlet.TldScanner$TldScannerCallback.scan(TldScanner.java:301)
at org.apache.tomcat.util.scan.StandardJarScanner.process(StandardJarScanner.java:313)
at org.apache.tomcat.util.scan.StandardJarScanner.scan(StandardJarScanner.java:245)
at org.apache.jasper.servlet.TldScanner.scanJars(TldScanner.java:262)
at org.apache.jasper.servlet.TldScanner.scan(TldScanner.java:106)
at org.apache.jasper.JspC.initServletContext(JspC.java:1535)
at org.apache.jasper.JspC.execute(JspC.java:1378)
at com.google.appengine.tools.admin.LocalJspC.main(LocalJspC.java:33)

那么同样的异常发生在很多其他的 jar 中，比如 javax.annotation-api-1.2.jar、asm-commons-5.0.1.jar、asm-5.0.1.jar、javax.transaction-api-1.2 .jar、javax.mail.glassfish-1.4.1.v201005082020.jar、org.apache.taglibs.taglibs-standard-spec-1.2.5.jar、org.apache.taglibs.taglibs-standard-impl-1.2.5 .jar 和其他大约 30 个。

但部署只是继续：

jul 27, 2017 11:15:08 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
jul 27, 2017 11:15:08 PM org.apache.jasper.JspC processFile
INFO: Built File: \index.jsp
2017-07-27 23:15:10.115:INFO::main: Logging initialized @175ms
2017-07-27 23:15:11.051:INFO:oeja.AnnotationConfiguration:main: Scanning elapsed time=501ms
0% Generated git repository information file.
Success.
Temporary staging for module default directory left in C:\Users\Leejjon\AppData\Local\Temp\gae-staging-blindepoule684
Services to deploy:

descriptor:      [C:\Users\Leejjon\AppData\Local\Temp\gae-staging-blindepoule684\app.yaml]
source:          [C:\Users\Leejjon\AppData\Local\Temp\gae-staging-blindepoule684]
target project:  [blindepoule]
target service:  [default]
target version:  [6]
target url:      [https://blindepoule.appspot.com]


Beginning deployment of service [default]...
Some files were skipped. Pass `--verbosity=info` to see which ones.
You may also view the gcloud log file, found at
[C:\Users\Leejjon\AppData\Roaming\gcloud\logs\2017.07.27\23.15.12.062000.log].
#============================================================#
#= Uploading 4 files to Google Cloud Storage                =#
#============================================================#
File upload done.
Updating service [default]...
..............done.
Updating service [default]...
.Waiting for operation [apps/blindepoule/operations/5106d598-f760-4079-a358-4b2148c622cf] to complete...
..done.
done.
Deployed service [default] to [https://blindepoule.appspot.com]

You can stream logs from the command line by running:
  $ gcloud app logs tail -s default

To view your application in the web browser run:
  $ gcloud app browse
'[2017-07-27 23:15:04] Maven build: Blindpool. Project: blindepoule. Version: 6' has been deployed successfully.

如您所见，它完成得很好，我应该担心摆脱警告吗？

更新：发现 Google 希望我们转而使用云工具 appengine maven 插件： https://cloud.google.com/appengine/docs/standard/java/tools/migrate-maven

如果我使用推荐的设置并运行gcloud appengine:deploy，我会得到与之前在 IntelliJ 中遇到的完全相同的错误。因此，使用旧的 appengine maven 插件是可行的，但它违背了 Google 的建议。

Answer 1

看来您需要在pom.xml 中正确管理版本。部分插件在指定版本下无法访问。

我试过了：

    <plugins>
    ...
        <plugin>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-maven-plugin</artifactId>
            <!--<version>${appengine.target.version}</version>-->
            <version>1.8.3</version>
            <configuration>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-maven-plugin</artifactId>
            <!--<version>${jetty.maven.plugin}</version>-->
            <version>9.4.0.v20161208</version>
        </plugin>
    </plugins>

然后我启动服务器没有问题。

---

插件和依赖版本可以不同（因为版本转移或清理存储库）。如果您想对依赖项和插件使用相同的版本，您可以使用我指定的插件版本或更改更多版本。

---

Connected to the target VM, address: '127.0.0.1:64711', transport: 'socket'
Jul 28, 2017 1:06:54 AM com.google.apphosting.utils.jetty.JettyLogger info
INFO: Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
Connected to server
Jul 27, 2017 10:06:54 PM com.google.apphosting.utils.jetty.JettyLogger info
INFO: jetty-6.1.x
Jul 27, 2017 10:06:55 PM com.google.apphosting.utils.jetty.JettyLogger info
INFO: Started SelectChannelConnector@localhost:8080
Jul 27, 2017 10:06:55 PM com.google.appengine.tools.development.AbstractModule startup
INFO: Module instance default is running at http://localhost:8080/
Jul 27, 2017 10:06:55 PM com.google.appengine.tools.development.AbstractModule startup
INFO: The admin console is running at http://localhost:8080/_ah/admin
Jul 28, 2017 1:06:55 AM com.google.appengine.tools.development.DevAppServerImpl doStart
INFO: Dev App Server is now running