加载 WebappClassLoader 时出错（出现错误）答案

【问题标题】：Error loading WebappClassLoader(Getting Error)加载 WebappClassLoader 时出错（出现错误）
【发布时间】：2015-06-20 04:52:55
【问题描述】：

我正在使用 resteasy/jersy 做一个 web 服务。在 tomcat 上运行时，我收到以下错误，但无法弄清楚发生了什么。我多次清理和运行项目但它不起作用。我使用 maven 添加依赖项。我的 Stacktrace 如下所示

Apr 14, 2015 7:21:43 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre7\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jre7/bin/client;C:/Program Files/Java/jre7/bin;C:/Program Files/Java/jre7/lib/i386;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;D:\java\eclipse\eclipse;;.
Apr 14, 2015 7:21:43 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:SnapshotHealthApp' did not find a matching property.
Apr 14, 2015 7:21:43 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-9999
Apr 14, 2015 7:21:43 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 394 ms
Apr 14, 2015 7:21:43 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Apr 14, 2015 7:21:43 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.43
Apr 14, 2015 7:21:43 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet jersey-serlvet as unavailable
Apr 14, 2015 7:21:43 PM org.apache.catalina.core.ApplicationContext log
SEVERE: Error loading WebappClassLoader
  context: /SnapshotHealthApp
  delegate: false
  repositories:
    /WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@5a384a
 com.sun.jersey.spi.container.servlet.ServletContainer
java.lang.ClassNotFoundException: com.sun.jersey.spi.container.servlet.ServletContainer
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1128)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1026)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4425)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4738)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1060)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:822)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1060)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
    at org.apache.catalina.core.StandardService.start(StandardService.java:525)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:759)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)

Apr 14, 2015 7:21:43 PM org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /SnapshotHealthApp threw load() exception
java.lang.ClassNotFoundException: com.sun.jersey.spi.container.servlet.ServletContainer
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1128)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1026)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4425)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4738)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1060)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:822)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1060)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
    at org.apache.catalina.core.StandardService.start(StandardService.java:525)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:759)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)

Apr 14, 2015 7:21:43 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-9999
Apr 14, 2015 7:21:43 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Apr 14, 2015 7:21:43 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/16  config=null
Apr 14, 2015 7:21:43 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 252 ms

Web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>SnapshotHealthApp</display-name>
  <servlet>

    <servlet-name>jersey-servlet</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
      <param-name>com.sun.jersey.config.property.packages</param-name>
      <param-value>com.snapshothealthapp.controller</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>jersey-servlet</servlet-name>
    <url-pattern>/api/*</url-pattern>
  </servlet-mapping>
</web-app>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>snapshot</groupId>
  <artifactId>snapshot</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>

  <repositories>
       <repository>
         <id>maven2-repository.java.net</id>
          <name>Java.net Repository for Maven</name>
          <url>http://download.java.net/maven/2/</url>
          <layout>default</layout>
       </repository>
</repositories>

<dependencies>

<dependency>
    <groupId>javax.ws.rs</groupId>
    <artifactId>jsr311-api</artifactId>
    <version>1.1.1</version>
</dependency>

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-client</artifactId>
    <version>1.9.1</version>
</dependency>

       <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.8.2</version>
          <scope>test</scope>
       </dependency>

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.2.4</version>
</dependency>

 <dependency>
    <groupId>com.googlecode.json-simple</groupId>
    <artifactId>json-simple</artifactId>
    <version>1.1</version>
  </dependency>
  <dependency>
    <groupId>com.codesnippets4all</groupId>
    <artifactId>quick-json</artifactId>
    <version>1.0.4</version>
</dependency>

<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20141113</version>
</dependency>
<dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.8.5</version>
    </dependency>
<dependency>
    <groupId>javax.json</groupId>
    <artifactId>javax.json-api</artifactId>
    <version>1.0</version>
</dependency>
<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-servlet</artifactId>
    <version>1.12</version>
</dependency>

      <dependency>
          <groupId>com.sun.jersey</groupId>
          <artifactId>jersey-server</artifactId>
          <version>1.8</version>
       </dependency>

</dependencies>

<build>
   <finalName>SnapshotHealthApp</finalName>
   <plugins>
      <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
             <configuration>
                <compilerVersion>1.5</compilerVersion>
                <source>1.5</source>
                <target>1.5</target>
             </configuration>
       </plugin>
   </plugins>
</build>
</project>

为解决上述错误做了很多尝试。任何帮助将不胜感激.....

【问题讨论】：

标签： java web-services maven jersey-2.0

【解决方案1】：

不要混用 Jersey 版本。这个

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-servlet</artifactId>
    <version>1.12</version>
</dependency>

是将所有内容都引入的主要依赖项。所以你不需要

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-server</artifactId>
    <version>1.8</version>
</dependency>

摆脱它。它将被拉入。并相应地更改 jersey-client 以匹配。

这个

<dependency>
    <groupId>javax.ws.rs</groupId>
    <artifactId>jsr311-api</artifactId>
    <version>1.1.1</version>
</dependency>

是冲突。 jersey-core-1.12 将 JAX-RS api 重新打包到它的模块中，上面的 jar 与它冲突。摆脱它。

我的其他建议

正如我所说，不要混合 Jersey 依赖版本。最好的办法是保留一个 Maven 属性，并将其用于所有 Jersey 依赖项

<properties>
    <jersey.version>1.12<jersey.version>
</properties>
...
<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-servlet</artifactId>
    <version>${jersey.version}</version>
</dependency>

除非你对使用 Jersey 1.12 有严格要求，否则我建议升级到 1.19。这将拉入您尝试使用的jsr311:1.1.1。

注意

这可能无法解决问题，因为我无法重现 ClassNotFoundException，但我能够产生由您的依赖项引起的其他异常。我想一旦加载了ServletContainer，它就会导致另一个问题。

我建议您在部署应用程序时查看 Tomcat webapps 目录，并查看所有 jar 是否都在您应用程序的 WEB-INF/lib 中。也许他们是罐子不是随着战争而建造的。

【讨论】：