Question

我有一个Maven项目，其中有一个Main.java类，其中包含我想从Windows命令提示符执行的main()方法。我使用以下命令执行它但它失败并显示错误消息（如下所示）。这个程序在IDE中工作正常。

stackoverflow Why am I getting a NoClassDefFoundError in Java?上的类似问题已被列出，但未提供解决方案。它只是详细解释了这个问题。

请指导。

执行主类的命令：

java -classpath target\jobchain-dataloader.jar com.ebayenterprise.ecp.jobs.Main

错误日志：

C:\office-data\v11-Projects\jobchain-dataloader>java -classpath target\jobchain-dataloader.jar com.ebayenterprise.ecp.jobs.Main
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/quartz/ScheduleBuilder
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
        at java.lang.Class.privateGetMethodRecursive(Unknown Source)
        at java.lang.Class.getMethod0(Unknown Source)
        at java.lang.Class.getMethod(Unknown Source)
        at sun.launcher.LauncherHelper.validateMainClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: org.quartz.ScheduleBuilder
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 7 more

Main.java

package com.ebayenterprise.ecp.jobs;   
public class Main {

    private static final Logger LOG = Logger.getLogger(Main.class);

    public static void main(String[] args) throws SchedulerException {
        LOG.debug("Scheduler started sucessfully.....");

        //get scheduler instance
        Scheduler scheduler = new StdSchedulerFactory().getScheduler();
        scheduler.start();

        //get scheduling time details
        Properties props = loadProperties("scheduler.properties");
        int mins = Integer.parseInt(props.getProperty("mins"));

        //kick off job
        scheduler.scheduleJob(getJobDetail(RecurringDataLoader.class), getJobTrigger(mins));
    }

    public static JobDetail getJobDetail(Class z) {
        return JobBuilder.newJob(z).withIdentity(RECURRING_DATA_LOADER_JOB, DATA_LOADER_JOB_GRP).build();
    }

    //create a simple trigger
    public static Trigger getJobTrigger(int mins) {
        Trigger trigger = TriggerBuilder.newTrigger()
                .withIdentity(RECURRING_DATA_LOADER_TRIGGER, DATA_LOADER_TRIGGER_GRP)
                .startNow()
                .withSchedule(simpleSchedule()
                        .withIntervalInMinutes(mins)
                        .repeatForever())
                .build();
        return trigger;
    }

}

pom.xml

   <dependencies>
        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc7</artifactId>
            <version>7.0</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>9.2-1004-jdbc41</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongo-java-driver</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.quartz-scheduler</groupId>
            <artifactId>quartz</artifactId>
            <version>2.2.1</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-mapper-asl</artifactId>
            <version>1.9.13</version>
        </dependency>
    </dependencies>

Answer 1

能够通过在pom中添加以下插件来使程序正常工作。

第一个依赖项在jar中创建lib文件，第二个依赖项在现有target目录中创建<plugin>  <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <version>2.6</version> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <classpathPrefix>lib/</classpathPrefix> <mainClass>com.ebayenterprise.ecp.jobs.Main</mainClass> </manifest> </archive> </configuration> </plugin> <plugin>  <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-dependency-plugin</artifactId> <version>2.10</version> <executions> <execution> <id>copy-dependencies</id> <phase>package</phase> <goals> <goal>copy-dependencies</goal> </goals> <configuration> <outputDirectory>${project.build.directory}/lib</outputDirectory> <overWriteReleases>false</overWriteReleases> <overWriteSnapshots>false</overWriteSnapshots> <overWriteIfNewer>true</overWriteIfNewer> </configuration> </execution> </executions> </plugin>文件夹，并复制其中的所有依赖项。

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使用java -classpath命令执行主类时的NoClassDefFoundError

1 个答案: