向码头添加自定义处理程序会引发 ClassNotFoundException

Question

我正在尝试向码头注入自定义处理程序。

我已经在我的应用程序代码中编写了处理程序，它被打包为一个战争。

package com.foo.bar

import javax.servlet.http.{HttpServletRequest, HttpServletResponse}
import org.eclipse.jetty.server.Request
import org.eclipse.jetty.server.handler.AbstractHandler

// scalastyle:off println
class CustomJettyHandler extends AbstractHandler {
  override def handle(target: String, baseRequest: Request,
                      request: HttpServletRequest, response: HttpServletResponse): Unit = {

    println("This is a custom jetty handler")
  }
}
// scalastyle:on println

然后我在jetty.xml 文件中注入了这个处理程序：

<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">
<Configure id="Server" class="org.eclipse.jetty.server.Server">
........
........
<Call name="insertHandler">
    <Arg>
      <New id="CustomJettyHandler" class="com.foo.bar.CustomJettyHandler"/>
    </Arg>
</Call>
........

我现在以独立模式运行码头。请注意，我将CustomJettyHandler.class 所在的位置传递给jetty-start.jar。

java -server -Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog -jar lib/jetty-start.jar OPTIONS=All --lib=lib/* --lib=webapps/root/WEB-INF/classes/com/foo/bar/* etc/jetty.xml etc/jetty-jmx.xml --debug

在我的应用程序日志中，我可以看到码头将我的自定义处理程序加载到其类路径，但最终由于ClassNotFoundException 而失败。有人能指出这哪里出了问题吗？

.......
rawlibref = webapps/root/WEB-INF/classes/com/foo/bar/*
expanded = webapps/root/WEB-INF/classes/com/foo/bar/*
getPaths('webapps/root/WEB-INF/classes/com/foo/bar/*')
Using relative path pattern: glob:**/webapps/root/WEB-INF/classes/com/foo/bar/*
Found [webapps/root/WEB-INF/classes/com/foo/bar/CustomJettyHandler.class]  /Users/...path_to_application.../webapps/root/WEB-INF/classes/com/foo/bar/CustomJettyHandler.class
Adding classpath component: /Users/...path_to_application.../webapps/root/WEB-INF/classes/com/foo/bar/CustomJettyHandler.class
.......
.......
.......
URLClassLoader.url[33] = file:/Users/...path_to_application.../webapps/root/WEB-INF/classes/com/foo/bar/CustomJettyHandler.class
Loaded 34 URLs into URLClassLoader
class org.eclipse.jetty.xml.XmlConfiguration - 9.4.24.v20191120
Command Line Args: /var/folders/z5/dmt38gq54kxcrrzpgvbl5m_c0000gp/T/start_6046998329479549547.properties /Users/...path_to_application.../etc/jetty.xml /Users/...path_to_application.../etc/jetty-jmx.xml
2020-05-27 14:46:13.676:INFO::main: Logging initialized @477ms to org.eclipse.jetty.util.log.StdErrLog
2020-05-27 14:46:13.934:INFO:oeju.TypeUtil:main: JVM Runtime does not support Modules
2020-05-27 14:46:14.007:WARN:oejx.XmlConfiguration:main: Config error at <Call name="insertHandler"><Arg>|      <New id="CustomJettyHandler" class="com.foo.bar.CustomJettyHandler"/>|    </Arg></Call> java.lang.ClassNotFoundException: com.foo.bar.CustomJettyHandler in file:///Users/...path_to_application.../etc/jetty.xml
2020-05-27 14:46:14.007:WARN:oejx.XmlConfiguration:main:
java.security.PrivilegedActionException: java.lang.ClassNotFoundException: com.foo.bar.CustomJettyHandler
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1837)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.eclipse.jetty.start.Main.invokeMain(Main.java:218)
    at org.eclipse.jetty.start.Main.start(Main.java:491)
    at org.eclipse.jetty.start.Main.main(Main.java:77)
Caused by:
java.lang.ClassNotFoundException: com.foo.bar.CustomJettyHandler
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.eclipse.jetty.util.Loader.loadClass(Loader.java:64)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.newObj(XmlConfiguration.java:1028)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.itemValue(XmlConfiguration.java:1638)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.value(XmlConfiguration.java:1539)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.access$500(XmlConfiguration.java:369)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration$AttrOrElementNode.getList(XmlConfiguration.java:1768)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration$AttrOrElementNode.getList(XmlConfiguration.java:1744)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.call(XmlConfiguration.java:919)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:512)
    at org.eclipse.jetty.xml.XmlConfiguration$JettyXmlConfiguration.configure(XmlConfiguration.java:454)
    at org.eclipse.jetty.xml.XmlConfiguration.configure(XmlConfiguration.java:354)
    at org.eclipse.jetty.xml.XmlConfiguration.lambda$main$0(XmlConfiguration.java:1874)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.jetty.xml.XmlConfiguration.main(XmlConfiguration.java:1837)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.eclipse.jetty.start.Main.invokeMain(Main.java:218)
    at org.eclipse.jetty.start.Main.start(Main.java:491)
    at org.eclipse.jetty.start.Main.main(Main.java:77)

Answer 1

你从哪里得到这个命令行？

java -server \
  -Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog\
  -jar lib/jetty-start.jar\
  OPTIONS=All \
  --lib=lib/* \
  --lib=webapps/root/WEB-INF/classes/com/foo/bar/* \
  etc/jetty.xml \
  etc/jetty-jmx.xml \
  --debug

这不适用于 Jetty 9.x 的 start.jar

一些建议

• 不要在 java 命令行上直接使用 XML，这是 start.jar 和 jetty-home 模块系统的责任（顺序非常重要）。
  您选择的etc/jetty.xml and etc/jetty-jmx.xml 是一个不完整的xml 列表。 （您缺少所有相关的 XML 文件）
• 不要编辑标准的 Jetty XML 文件，保留它们，否则以后升级会变得复杂。改用 XML 来注入您的行为（参见下面的示例）
• OPTIONS 不受 Jetty 9.x 支持（这是老式 Codehaus / Jetty 6 行为）
• 不鼓励您使用--lib=，它仅支持具有爆炸类树的jar 或目录的完全限定路径（不支持相对路径，不支持glob）。
• -Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog 是一种设置日志记录的苛刻方式。创建一个jetty-logging.properties 文件并确保它存在于类路径中。

jetty-logging.properties的示例内容

org.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StdErrLog
org.eclipse.jetty.LEVEL=INFO
#org.eclipse.jetty.deploy.LEVEL=DEBUG

改为这样做。

为您的新处理程序创建一个基于注入的 XML。

my-handler.xml

<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">

<Configure id="Server" class="org.eclipse.jetty.server.Server">
    <Call name="insertHandler">
        <Arg>
            <New id="CustomJettyHandler" class="com.foo.bar.CustomJettyHandler" />
        </Arg>
    </Call>
</Configure>

接下来正确创建您的 jetty-base 目录（对于 jetty 的 start.jar）

# Create your "jetty-base" directory
$ mkdir /path/to/myjettybase
$ cd /path/to/myjettybase

# Establish the basic files / directories / modules that you want to use
# You can find the configuration in start.ini or start.d/*.ini
$ java -jar /path/to/jetty-home/start.jar --add-to-start=http,jmx,deploy,ext,resources

# Copy your custom handler JAR into place
$ cp /path/to/my-handlers.jar /path/to/myjettybase/lib/ext/
# Copy your custom handler XML into place
$ cp /path/to/my-handler.xml /path/to/myjettybase/etc/
# Ensure that the custom handler XML is loaded into the jetty instance at the right point in the XML load order by declaring it to be used in a custom INI
$ mkdir start.d
$ echo "etc/my-handler.xml" >> start.d/my-handlers.ini

# Copy your jetty-logging.properties into place
$ cp /path/to/my-jetty-logging.properties /path/to/myjettybase/resources/jetty-logging.properties

# verify that your configuration looks sane (including the server classpath)
$ cd /path/to/myjettybase
$ java -jar /path/to/jetty-home/start.jar --list-config

# run your instance
$ cd /path/to/myjettybase
$ java -jar /path/to/jetty-home/start.jar

但这还不是全部，鉴于您似乎想在 maven 风格的项目（或项目布局）中使用 jetty-home，您也可以这样做！

可以在...上找到一个示例项目来展示这一点

https://github.com/jetty-project/servlet-error-page-handling

该 maven 项目也是一个有效的 jetty-base 目录，适合由您机器上其他地方的 jetty-home 存档执行。