使用maven构建jar显示错误答案

【问题标题】：jar build using maven showing error使用maven构建jar显示错误
【发布时间】：2014-12-27 18:45:18
【问题描述】：

我已经构建了一个应用程序，它从一些 xml 文件的Count 标记中获取值并将其写入输出的 excel XLSX 文件。

我的程序中有两个由main() 调用的函数。第一个是readXml()，它读取xml文件，第二个是writeXlsx()，它写入输出的excel文件。

我使用maven添加依赖和构建jar文件。

当我运行创建的 jar 时，它适用于一半的程序，但在尝试编写 XLSX 时会出错。出现的错误是：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/poi/xssf/usermodel/XSSFWorkbook
    at com.mpstddn.App.writeXLSX(App.java:107)
    at com.mpstddn.App.main(App.java:64)
Caused by: java.lang.ClassNotFoundException: org.apache.poi.xssf.usermodel.XSSFWorkbook

当我从 Eclipse 运行它时，相同的程序运行良好，但当我制作一个 jar 并运行它时会出错。在我看来，jar 无法包含 apache poi lib。我是 Maven 新手，不知道我在哪里犯错。这是我的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>com.mpstddn.java</groupId>
    <artifactId>myMavenProject</artifactId>
    <packaging>jar</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>myMaven</name>
    <url>http://maven.apache.org</url>
    <dependencies>
       <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.15</version>
        <exclusions>
            <exclusion>
                <groupId>com.sun.jdmk</groupId>
                <artifactId>jmxri</artifactId>
            </exclusion>
            <exclusion>
                <groupId>javax.jms</groupId>
                <artifactId>jms</artifactId>
            </exclusion>
            <exclusion>
                <groupId>com.sun.jmx</groupId>
                <artifactId>jmxri</artifactId>
            </exclusion>
            <exclusion>
                <groupId>com.sun.jdmk</groupId>
                <artifactId>jmxtools</artifactId>
            </exclusion>
        </exclusions>
      </dependency>
      <dependency>
          <groupId>org.apache.poi</groupId>
          <artifactId>openxml4j</artifactId>
          <version>1.0-beta</version>
      </dependency>     
       <dependency>
          <groupId>org.apache.poi</groupId>
          <artifactId>poi-ooxml</artifactId>
          <version>3.10-FINAL</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-scratchpad</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.10-FINAL</version>
        </dependency>
     </dependencies>
    <build>
        <sourceDirectory>src</sourceDirectory>
        <scriptSourceDirectory>src\main\scripts</scriptSourceDirectory>
        <testSourceDirectory>src\test\java</testSourceDirectory>
        <outputDirectory>target\classes</outputDirectory>
        <testOutputDirectory>target\test-classes</testOutputDirectory>
    <resources>
        <resource>
            <directory>src</directory>
            <excludes>
                <exclude>**/*.java</exclude>
            </excludes>
        </resource>
        <resource>
            <directory>lib</directory>
            <excludes>
                <exclude>**/*.java</exclude>
                <exclude>**/*.jar</exclude>
            </excludes>
        </resource>
 </resources>
 <pluginManagement>
        <plugins>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.2-beta-5</version>
            </plugin>
            <plugin>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.1</version>
            </plugin>
            <plugin>
                <artifactId>maven-release-plugin</artifactId>
                <version>2.0</version>
            </plugin>
        </plugins>
 </pluginManagement>
  <plugins>
        <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                        <archive>
                                <manifest>
                                        <mainClass>com.mpstddn.App</mainClass>
                                </manifest>
                        </archive>
                </configuration>
            </plugin>
       <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <executions>
                <execution>
                    <id>default-testCompile</id>
                    <phase>test-compile</phase>
                    <goals>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
                <execution>
                    <id>default-compile</id>
                    <phase>compile</phase>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                    <configuration>
                        <source>1.7</source>
                        <target>1.7</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <artifactId>maven-clean-plugin</artifactId>
            <version>2.4.1</version>
            <executions>
                <execution>
                    <id>default-clean</id>
                    <phase>clean</phase>
                    <goals>
                        <goal>clean</goal>
                    </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
            <artifactId>maven-install-plugin</artifactId>
            <version>2.3.1</version>
            <executions>
                <execution>
                    <id>default-install</id>
                    <phase>install</phase>
                    <goals>
                        <goal>install</goal>
                    </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
            <artifactId>maven-resources-plugin</artifactId>
            <version>2.5</version>
            <executions>
                <execution>
                    <id>default-resources</id>
                    <phase>process-resources</phase>
                    <goals>
                        <goal>resources</goal>
                    </goals>
                </execution>
                <execution>
                    <id>default-testResources</id>
                    <phase>process-test-resources</phase>
                    <goals>
                        <goal>testResources</goal>
                    </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.10</version>
            <executions>
                  <execution>
                    <id>default-test</id>
                      <phase>test</phase>
                     <goals>
                        <goal>test</goal>
                     </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
             <artifactId>maven-jar-plugin</artifactId>
            <version>2.3.2</version>
            <configuration>
                <archive>
                     <manifest>
                         <addClasspath>true</addClasspath>
                                <classpathPrefix>lib/</classpathPrefix>
                             <mainClass>com.mpstddn.App</mainClass>
                      </manifest>
                 </archive>
            </configuration>
             <executions>
                <execution>
                     <id>default-jar</id>
                    <phase>package</phase>
                    <configuration>
                        <packagingExcludes>*.jar</packagingExcludes>
                    </configuration>
                    <goals>
                        <goal>jar</goal>
                    </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
            <artifactId>maven-deploy-plugin</artifactId>
            <version>2.7</version>
            <executions>
                <execution>
                    <id>default-deploy</id>
                    <phase>deploy</phase>
                    <goals>
                        <goal>deploy</goal>
                    </goals>
                </execution>
            </executions>
         </plugin>
         <plugin>
          <artifactId>maven-site-plugin</artifactId>
            <version>3.0</version>
            <executions>
                <execution>
                    <id>default-site</id>
                    <phase>site</phase>
                    <goals>
                        <goal>site</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>target\site</outputDirectory>
                        <reportPlugins>
                            <reportPlugin>
                                <groupId>org.apache.maven.plugins</groupId>
                                <artifactId>maven-project-info-reports-plugin</artifactId>
                            </reportPlugin>
                        </reportPlugins>
                    </configuration>
                </execution>
                <execution>
                    <id>default-deploy</id>
                    <phase>site-deploy</phase>
                    <goals>
                        <goal>deploy</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>target\site</outputDirectory>
                        <reportPlugins>
                            <reportPlugin>
                                <groupId>org.apache.maven.plugins</groupId>
                                <artifactId>maven-project-info-reports-plugin</artifactId>
                            </reportPlugin>
                        </reportPlugins>
                    </configuration>
                </execution>
            </executions>
            <configuration>
                <outputDirectory>target\site</outputDirectory>
                <reportPlugins>
                    <reportPlugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-project-info-reports-plugin</artifactId>
                    </reportPlugin>
                </reportPlugins>
            </configuration>
        </plugin>
       </plugins>
     </build>
 </project>

我创建 jar 的方式： right click on project in eclipse -> run as -> Maven install 这将在项目文件夹内的target 目录中创建一个 jar 文件。

我正在使用命令提示符运行 jar 文件：

java -jar myMavenProject-0.0.1-SNAPSHOT.jar X:\input_directory input.xml 9

【问题讨论】：

您是否设置了运行时类路径（当您启动 jar 时）？您应该编辑并告诉我们您是如何“运行”的
org.apache.poi.xssf.usermodel.XSSFWorkbook 应该是 poi-ooxml - 很难说为什么找不到它。正如上面的评论中提到的，你运行这个东西来解决你的错误的方式可能是调查的方式。
你是如何创建 jar 的？
嗯...快速浏览一下，您的 Maven 配置似乎还可以。并且依赖项应该打包到您的 .jar 中。是这样吗？我目前唯一不知道的是您的资源定义将如何表现
我的建议：不要假设，一定要确定。所以从你的构建中删除所有你不需要/不知道的插件，阅读你需要的那个的文档，找出哪个负责做你的“带有依赖关系的jar”（这不是默认功能）并交叉检查它配置

标签： java maven jar pom.xml

【解决方案1】：

所以你的问题不是基于依赖，而是因为你配置了 maven-assembly-plugin 错误：

<project>
  [...]
  <build>
    [...]
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-assembly-plugin</artifactId>
        <version>2.5</version>
        <configuration>
          <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
          </descriptorRefs>
        </configuration>
        <executions>
          <execution>
           <id>package</id>
           <goals>
             <goal>single</goal>
           <goals>
           <phase>package</phase>
          </execution>
        </executions>
      </plugin>
    </plugins>
 </build>
</project>

问题是 maven-assembly-plugin 默认不绑定到任何生命周期阶段。之后尝试：

mvn clean package

并检查生成的 jar 文件 (target/WhatEver-x.x-SNAPSHOT-jar-with-dependencies.jar)。

【讨论】：

@khmarbaise 我已经添加了这个依赖，但我认为这个依赖没有被打包到我正在创建的 jar 中。