Question

我创建了一个java应用程序来读取Gmail地址。当我从IDE（Intellij）执行脚本时，脚本运行完美。但是通过生成一个jar文件并尝试执行jar：

java -jar my-jar-file.jar

我有这个错误：

java.lang.NoClassDefFoundError: javax/mail/Part
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2625)
at java.lang.Class.getMethod0(Class.java:2866)
at java.lang.Class.getMethod(Class.java:1676)
at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)
Caused by: java.lang.ClassNotFoundException: javax.mail.Part
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 6 more
Exception in thread "main"

这是我的POM文件：

 <?xml version="1.0" encoding="UTF-8"?>
 <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>my.group.id</groupId>
<artifactId>readMail</artifactId>
<version>1.0-SNAPSHOT</version>

<build>
    <plugins>
        <plugin>
            <!-- Build an executable JAR -->
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>my.MainClass</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>
<properties>
   ....
</properties>
<dependencies>
    ....
    <!-- POP, SMTP, IMAP -->
    <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.4.7</version>
    </dependency>
    <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mailapi</artifactId>
        <version>1.4.3</version>
    </dependency>
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1</version>
    </dependency>
    ....
</dependencies>

Answer 1

您必须使用Maven Shade Plugin创建一个包含所有依赖关系树的胖jar。

Answer 2

https://maven.apache.org/plugins/maven-shade-plugin/examples/executable-jar.html

尝试将它编译为胖jar，将依赖项嵌入到jar中，这可能会起作用我不确定

java -jar my-jar.jar java.lang.NoClassDefFoundError：javax / mail / Part

2 个答案: