使用Jdivert库运行时出现java.lang.ClassNotFoundException错误求助

你的报错java.lang.NoClassDefFoundError: com/sun/jna/Pointer本质是项目缺少JNA依赖——Jdivert库依赖JNA（Java Native Access）实现本地API调用，但当前pom.xml仅引入了Jdivert，未显式添加JNA依赖（部分情况下Maven不会自动传递依赖）。

解决方案：添加JNA依赖到pom.xml #

在你的<dependencies>节点中加入JNA的依赖项，推荐使用与Jdivert 1.1兼容的JNA 5.x版本：

<dependency>
    <groupId>net.java.dev.jna</groupId>
    <artifactId>jna</artifactId>
    <version>5.13.0</version>
</dependency>

修改后的完整pom.xml如下：

<?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>org.example</groupId>
    <artifactId>Glacial1.1</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>com.github.ffalcinelli</groupId>
            <artifactId>jdivert</artifactId>
            <version>1.1</version>
        </dependency>
        <!-- 添加JNA依赖 -->
        <dependency>
            <groupId>net.java.dev.jna</groupId>
            <artifactId>jna</artifactId>
            <version>5.13.0</version>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>18</maven.compiler.source>
        <maven.compiler.target>18</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

</project>

验证步骤 #

1. 执行mvn clean install重新构建项目，确保依赖被正确下载
2. 重新运行你的Main类，此时JNA类会被正确加载，报错应该消失

附：你的报错信息 #

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/jna/Pointer
    at org.example.Main.main(Main.java:11)
Caused by: java.lang.ClassNotFoundException: com.sun.jna.Pointer
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 1 more

你的测试代码 #

public class Main {
    public static void main(String[] args) throws WinDivertException {
        System.out.println("Hello world!");

        WinDivert w = new WinDivert("tcp.DstPort == 80 and tcp.PayloadLength > 0");

        w.open(); // packets will be captured from now on

        Packet packet = w.recv();  // read a single packet
        System.out.println(packet);
        w.send(packet);  // re-inject the packet into the network stack

        w.close();  // stop capturing packets
    }
}

内容的提问来源于stack exchange，提问作者frank