Question

（我知道之前已经提出过这个问题，但是我无法用这些答案来解决这个问题）
我是java的新手，当我mvn -X -f "C:\xampp\perl\vendor\lib\Apache\apache-maven-3.5.3\bin\data-mqtt\pom.xml" clean compile exec:java时，我试图编写一些代码来访问和使用来自https://console.thethingsnetwork.org/的数据我明白了（来自终端的调试/错误）

java.lang.ClassNotFoundException：App 在java.net.URLClassLoader.findClass（URLClassLoader.java:466）在java.lang.ClassLoader.loadClass（ClassLoader.java:566） at java.lang.ClassLoader.loadClass（ClassLoader.java:499）在org.codehaus.mojo.exec.ExecJavaMojo $ 1.run（ExecJavaMojo.java:270）在java.lang.Thread.run（Thread.java:844）[INFO] -------------------------------- ---------------------------------------- [INFO] BUILD FAILURE [INFO] -------------------------------------------------- ---------------------- [INFO]总时间：5.844秒[INFO]完成于： 2018-06-18T10：47：08 + 02:00 [INFO] -------------------------------------------------- ---------------------- [错误]无法执行目标 org.codehaus.mojo：exec-maven-plugin：1.6.0：java（default-cli）on project data-mqtt：执行Java时发生异常类。应用 - ＆gt; [帮助1] org.apache.maven.lifecycle.LifecycleExecutionException：失败执行目标org.codehaus.mojo：exec-maven-plugin：1.6.0：java 项目数据上的（default-cli）-mqtt：发生异常时执行Java类。应用在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:213）在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:154）在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:146）在org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject （LifecycleModuleBuilder.java:117）在org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject （LifecycleModuleBuilder.java:81）在org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build （SingleThreadedBuilder.java:56）在org.apache.maven.lifecycle.internal.LifecycleStarter.execute（LifecycleStarter.java:128）在org.apache.maven.DefaultMaven.doExecute（DefaultMaven.java:305）在org.apache.maven.DefaultMaven.doExecute（DefaultMaven.java:192）在org.apache.maven.DefaultMaven.execute（DefaultMaven.java:105）在org.apache.maven.cli.MavenCli.execute（MavenCli.java:956）在org.apache.maven.cli.MavenCli.doMain（MavenCli.java:290）在org.apache.maven.cli.MavenCli.main（MavenCli.java:194） at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at jdk.internal.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62） at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:564）在org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced （Launcher.java:289）在org.codehaus.plexus.classworlds.launcher.Launcher.launch（Launcher.java:229）在org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode （Launcher.java:415）在org.codehaus.plexus.classworlds.launcher.Launcher.main（Launcher.java:356）引起： org.apache.maven.plugin.MojoExecutionException：发生异常在执行Java类时。应用在org.codehaus.mojo.exec.ExecJavaMojo.execute（ExecJavaMojo.java:339）在org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo（DefaultBuildPluginManager.java:137）在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:208）在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:154）在org.apache.maven.lifecycle.internal.MojoExecutor.execute（MojoExecutor.java:146）在org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject （LifecycleModuleBuilder.java:117）在org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject （LifecycleModuleBuilder.java:81）在org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build （SingleThreadedBuilder.java:56）在org.apache.maven.lifecycle.internal.LifecycleStarter.execute（LifecycleStarter.java:128）在org.apache.maven.DefaultMaven.doExecute（DefaultMaven.java:305）在org.apache.maven.DefaultMaven.doExecute（DefaultMaven.java:192）在org.apache.maven.DefaultMaven.execute（DefaultMaven.java:105）在org.apache.maven.cli.MavenCli.execute（MavenCli.java:956）在org.apache.maven.cli.MavenCli.doMain（MavenCli.java:290）在org.apache.maven.cli.MavenCli.main（MavenCli.java:194） at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at jdk.internal.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62） at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:564）在org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced （Launcher.java:289）在org.codehaus.plexus.classworlds.launcher.Launcher.launch（Launcher.java:229）在org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode （Launcher.java:415） at org.codehaus.plexus.classworlds.launcher.Launcher.main（Launcher.java:356）引起：java.lang.ClassNotFoundException：App 在java.net.URLClassLoader.findClass（URLClassLoader.java:466）在java.lang.ClassLoader.loadClass（ClassLoader.java:566） at java.lang.ClassLoader.loadClass（ClassLoader.java:499）在org.codehaus.mojo.exec.ExecJavaMojo $ 1.run（ExecJavaMojo.java:270）在java.lang.Thread.run（Thread.java:844）

到目前为止这是我的App.java

 `
public class App {
public static Client client;

public static void main(String[] args) {
    String region = "eu";
    String appId = "stuf1";
    String accessKey = "stuf2";

   try {
        client = new Client(region, appId, accessKey);
    } catch (URISyntaxException var5) {
        System.out.println(var5);
    }
    client.onError((_error) -> {
        System.out.println("error: " + _error.getMessage());
    });
    client.onConnected((_client) -> {
        System.out.println("connected !");
    });
}}

和我的pom.xml

    <repositories>
    <repository>
      <id>Codehaus Mojo</id>
      <name>Codehaus Mojo</name>
      <url>https://oss.sonatype.org/content/repositories/codehaus- 
      snapshots/</url>
      </repository>
  </repositories>
    <build>
    <plugins>
    <plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.6.0</version>
          <configuration>
            <classpathScope>test</classpathScope>
            <mainClass>App</mainClass>
          </configuration>
          <executions>
            <execution>
              <id>run-App.java</id>
              <phase>integration-test</phase>
              <goals><goal>java</goal></goals>
            </execution>
          </executions>
        </plugin>
        <plugin>
          <artifactId>maven-assembly-plugin</artifactId>

          <configuration>
            <descriptorRefs>
              <descriptorRef>jar-with-dependencies</descriptorRef>
            </descriptorRefs>
          </configuration>

          <executions>
            <execution>
              <id>make-assembly</id>
              <phase>package</phase>
              <goals>
                <goal>single</goal>
              </goals>
            </execution>
          </executions>
        </plugin>

        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
         <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.7.0</version>
          <configuration>
            <staleMillis>1</staleMillis>
            <useIncrementalCompilation>false</useIncrementalCompilation>
          </configuration>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.21.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

如果有人可以帮助我，如果您需要更多详细信息，请致谢。

Answer 1

没有更改适当的路径 <mainClass>App</mainClass>至<mainClass>org.thethingsnetwork.samples.mqtt.App</mainClass>

LORA上的maven中的java.lang.ClassNotFoundException

1 个答案: