Question

我正在构建一个Web应用程序并使用apache poi来处理Excel工作表。当我启动服务器时，我得到以下异常。事情是它曾经工作正常，直到我试图建立它并部署在heroku（但可能是无关紧要的）。有人有想法吗？

INFO: Starting service Catalina
Apr 15, 2016 8:28:35 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.53
Apr 15, 2016 8:28:36 PM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Exception sending context initialized event to listener instance of class org.engine.OnStartup
java.lang.NoClassDefFoundError: org/apache/poi/EncryptedDocumentException
    at org.engine.OnStartup.contextInitialized(OnStartup.java:16)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: org.apache.poi.EncryptedDocumentException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    ... 10 more

我的pom.xml文件：

<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>psilos-toy</groupId>
<artifactId>psilos-toy</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-server</artifactId>
        <version>1.8</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.3.1</version>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.2.4</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.httpcache4j.resolvers</groupId>
        <artifactId>resolvers-net-urlconnection</artifactId>
        <version>4.0-M6</version>
    </dependency>

    <!-- Apache POI,for handling Excel Files -->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>3.14</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>3.14</version>
    </dependency>
    <!-- jersey -->
    <dependency>
        <groupId>com.sun.jersey</groupId>
        <artifactId>jersey-server</artifactId>
        <version>1.8</version>
    </dependency>
</dependencies>

和我的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/j2ee" xmlns:web="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" id="WebApp_ID" version="2.4">
  <display-name>Restful Web Application</display-name>
  <servlet>
    <servlet-name>jersey-serlvet</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>org.endpoints</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>jersey-serlvet</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>
  <listener>
    <listener-class>org.engine.OnStartup</listener-class>
  </listener>
</web-app>

Answer 1

也许它正在使用classpath上有poi类的Tomcat设置。在新的Heroku设置中，也许你没有Tomcat 7提供的那些类（我没有彻底检查poi类是否与Tomcat 7捆绑在一起）。

您可以做的最简单的事情是通过将poi类与您的应用程序捆绑在一起来构建一个独立的应用程序。这会增加您的应用程序的大小，但您可以控制poi库版本。当然，您始终可以将库复制到已定义的文件夹（您知道Tomcat从中加载类）。有关详细信息，请参阅maven-shade-plugin。

java.lang.NoClassDefFoundError：org / apache / poi / EncryptedDocumentException

1 个答案: