由于缺少库，从命令行运行可执行 jar 失败

Question

我使用以下构建配置从 maven 创建了一个可执行 jar：

<plugins>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.2</version>
    <configuration>
      <source>1.8</source>
      <target>1.8</target>
    </configuration>
  </plugin>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>copy-dependencies</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>copy-dependencies</goal>
            </goals>
            <configuration>
              <outputDirectory>${project.build.directory}/${project.build.targetName}/lib</outputDirectory>
                <overWriteReleases>false</overWriteReleases>
                <overWriteSnapshots>false</overWriteSnapshots>
                <overWriteIfNewer>true</overWriteIfNewer>
                <excludeScope>test</excludeScope>
                <includeScope>compile</includeScope>
            </configuration>
        </execution>
    </executions>
  </plugin>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <configuration>
        <archive>
            <manifest>
                <addClasspath>true</addClasspath>
                <classpathPrefix>lib/</classpathPrefix>
                <packageName>${project.build.packageName}</packageName>
                <mainClass>${project.build.packageName}.${project.build.className}</mainClass>
            </manifest>
            <manifestEntries>
                <Class-Path>.</Class-Path>
            </manifestEntries>
        </archive>
        <finalName>${project.build.targetName}/${project.build.targetName}</finalName>
    </configuration>
  </plugin>

其中生成了以下文件：

./lib/axis-2878297.jar
./lib/axis-wsdl4j-1.5.1.jar
./lib/(other dependencies jars)
./target.jar

1.如果我以这种方式从命令行运行这个jar：

java -jar target.jar

它会产生异常：

Exception in thread "main" java.lang.NoClassDefFoundError: javax/wsdl/OperationType
        at org.apache.axis.description.OperationDesc.<clinit>(OperationDesc.java:59)
        ...

2.如果我以其他方式运行它：

java -cp "target.jar;lib\*" com.test.Main

执行会成功。

P.S.我尝试将 -verbose:class 放入命令中。

对于案例 1，它显示：

[Loaded org.apache.axis.description.OperationDesc from file:/C:/build/lib/axis-2878297.jar]
[Loaded java.lang.Throwable$PrintStreamOrWriter from C:\Program Files\Java\jre1.8.0_74\lib\rt.jar]
[...]

虽然情况 2 显示：

[Loaded org.apache.axis.description.OperationDesc from file:/C:/build/lib/axis-2878297.jar]
[Loaded javax.wsdl.OperationType from file:/C:/build/lib/axis-wsdl4j-1.5.1.jar]
[...]

案例1失败的原因是什么？

谢谢。

Answer 1

好的，我知道原因了：

在 pom.xml 中，我将 axis-wsdl4j 的范围设置为“已提供”，这表明我希望 JDK 或容器在运行时提供依赖项。所以当 maven 写 manifest.mf 时，它会跳过这个依赖。

感谢所有的答案和帮助。

<dependency>
    <groupId>axis</groupId>
    <artifactId>axis-wsdl4j</artifactId>
    <version>1.5.1</version>
    <scope>provided</scope>
</dependency>

Answer 2

我能够使用Maven shade plugin 完成这项工作。

我使用了Mykong的教程。

演示应用是一个使用 Joda 时间的命令行应用：

package com.mykong.core.utils;

import org.apache.log4j.Logger;
import org.joda.time.LocalDate;

/**
 * Hello world!
 * @link http://www.mkyong.com/maven/how-to-create-a-jar-file-with-maven/
 */
public class App {
    public static final Logger LOGGER = Logger.getLogger(App.class);

    public static void main(String[] args) {
        System.out.println(getLocalCurrentDate());
    }

    private static String getLocalCurrentDate() {
        String result = "";
        try {
            if (LOGGER.isDebugEnabled()) {
                LOGGER.debug("enter getLocalCurrentDate");
            }
            result = new LocalDate().toString();
        } finally {
            if (LOGGER.isDebugEnabled()) {
                LOGGER.debug("exit getLocalCurrentDate");
            }
        }
        return result;
    }
}

这是我的 pom.xml；使其适应您的目的。

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mykong.core.utils</groupId>
  <artifactId>dateUtils</artifactId>

  <packaging>jar</packaging>

  <version>1.0-SNAPSHOT</version>
  <name>dateUtils</name>
  <url>http://maven.apache.org</url>

  <properties>
    <jdk.version>1.8</jdk.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>joda-time</groupId>
      <artifactId>joda-time</artifactId>
      <version>2.9.1</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
  </dependencies>

  <build>
    <finalName>dateutils</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>2.4.3</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <manifestEntries>
                            <Main-Class>com.mykong.core.utils.App</Main-Class>
                            <Build-Number>1</Build-Number>
                        </manifestEntries>
                    </transformer>
                </transformers>
            </configuration>
        </plugin>
    </plugins>
  </build>

    <pluginRepositories>
        <pluginRepository>
            <id>central</id>
            <url>http://repo1.maven.org/maven2/</url>
        </pluginRepository>
    </pluginRepositories>
</project>