如何在包含本機代碼的Java應用程序中使用命令行執行Maven主類？

Question

我想使用命令行執行我的Maven項目獨立類。

JnetSampleTest.java-

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.jnetpcap.Pcap;
import org.jnetpcap.PcapIf;
import org.jnetpcap.packet.PcapPacket;
import org.jnetpcap.packet.PcapPacketHandler;

public class JnetSampleTest {

    public static void main(String[] args) {

        List<PcapIf> alldevs = new ArrayList<PcapIf>(); // Will be filled with NICs
        StringBuilder errbuf = new StringBuilder(); // For any error msgs

        int r = Pcap.findAllDevs(alldevs, errbuf);
        if (r == Pcap.NOT_OK || alldevs.isEmpty()) {
            System.err.printf("Can't read list of devices, error is %s", errbuf.toString());
            return;
        }

        System.out.println("Network devices found:");

        int i = 0;
        for (PcapIf device : alldevs) {
            String description = (device.getDescription() != null) ? device.getDescription()
                    : "No description available";
            System.out.printf("#%d: %s [%s]\n", i++, device.getName(), description);
        }

        PcapIf device = alldevs.get(8); // We know we have atleast 1 device
        PcapIf d = new PcapIf();

        System.out.printf("\nChoosing '%s' on your behalf:\n",
                (device.getDescription() != null) ? device.getDescription() : device.getName());

        int snaplen = 64 * 1024; // Capture all packets, no trucation
        int flags = Pcap.MODE_PROMISCUOUS; // capture all packets
        int timeout = 10 * 1000; // 10 seconds in millis
        Pcap pcap = Pcap.openLive(device.getName(), snaplen, flags, timeout, errbuf);

        if (pcap == null) {
            System.err.printf("Error while opening device for capture: " + errbuf.toString());
            return;
        }

        PcapPacketHandler<String> jpacketHandler = new PcapPacketHandler<String>() {
            public void nextPacket(PcapPacket packet, String user) {
                System.out.printf("Received packet at %s caplen=%-4d len=%-4d %s\n",
                        new Date(packet.getCaptureHeader().timestampInMillis()), packet.getCaptureHeader().caplen(), // Length
                        packet.getCaptureHeader().wirelen(), // Original length
                        user // User supplied object
                );
            }
        };

        pcap.loop(10, jpacketHandler, "jNetPcap rocks!");
        pcap.close();
    }
}

通過遵循本教程 ，我為jnetpcap創建了用戶庫，並將其添加到項目中。

在eclipse中，此代碼運行良好，但我想使用命令行執行此代碼，因此我在pom.xml中的示例代碼下方添加了-

<build>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.2.1</version>
            <executions>
                <execution>
                    <goals>
                        <goal>java</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <mainClass>com.JnetSampleTest.JnetSampleTest</mainClass>
            </configuration>
        </plugin>
    </plugins>
</build>

我嘗試使用此命令執行我的主類-

mvn exec:java -Dexec.mainClass="com.JnetSampleTest.JnetSampleTest"

我遇到這個例外-

[WARNING] 
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:297)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.UnsatisfiedLinkError: com.slytechs.library.NativeLibrary.dlopen(Ljava/lang/String;)J
    at com.slytechs.library.NativeLibrary.dlopen(Native Method)
    at com.slytechs.library.NativeLibrary.<init>(Unknown Source)
    at com.slytechs.library.JNILibrary.<init>(Unknown Source)
    at com.slytechs.library.JNILibrary.loadLibrary(Unknown Source)
    at com.slytechs.library.JNILibrary.register(Unknown Source)
    at com.slytechs.library.JNILibrary.register(Unknown Source)
    at com.slytechs.library.JNILibrary.register(Unknown Source)
    at org.jnetpcap.Pcap.<clinit>(Unknown Source)

如何使用命令行執行此類？

Answer 1

本機庫丟失。 可能是x86與x64的問題。

Answer 2

當找不到代碼正在尋找的so / dll文件時，會發生此類錯誤。 請確保在Windows system32文件夾中保存了jnetpcap的.dll文件。

IntelliJ的過程應與jnetpcap.com/?q=eclipse（或NetBeans）上的過程相似。 我對IntelliJ不熟悉，但是...您可以嘗試將本機庫（Linux上的.so文件，Windows上的.dll文件，Mac上的.dylib文件）復制到項目的主目錄中。