Question

我开始使用Maven并遇到了一个我无法解决的问题。我的应用程序运行所需的jar文件似乎不在类路径中。在mvn包装期间，Maven不应该照顾这个吗？

当我运行mvn包时，我收到错误：

[ERROR] /home/dev/Desktop/maventest/my-app/src/main/java/com/mycompany/app/App.java:[79,9] cannot find symbol
  symbol:   class UpnpService
  location: class com.mycompany.app.App
[ERROR] /home/dev/Desktop/maventest/my-app/src/main/java/com/mycompany/app/App.java:[79,39] cannot find symbol
  symbol:   class UpnpServiceImpl
  location: class com.mycompany.app.App

示例代码确实说：“您需要在类路径上使用cling-core.jar及其依赖项（无缝 - * .jar文件）来构建和运行此代码。”

但这不是maven应该照顾的东西吗？如果没有，我如何包含这些文件？

这是我的pom.xml：

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>my-app</name>
  <url>http://maven.apache.org</url>

  <repositories>
    <repository>
      <id>4thline-repo</id>
      <url>http://4thline.org/m2</url>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.fourthline.cling</groupId>
      <artifactId>cling-core</artifactId>
      <version>2.1.1</version>
    </dependency>
  </dependencies>
</project>

以下是我正在尝试运行的示例代码：

package com.mycompany.app;

import org.fourthline.cling.model.message.header.STAllHeader;
import org.fourthline.cling.model.meta.LocalDevice;
import org.fourthline.cling.model.meta.RemoteDevice;
import org.fourthline.cling.registry.Registry;
import org.fourthline.cling.registry.RegistryListener;

/**
 * Runs a simple UPnP discovery procedure.
 */
public class App {

    public static void main(String[] args) throws Exception {

        // UPnP discovery is asynchronous, we need a callback
        RegistryListener listener = new RegistryListener() {

            public void remoteDeviceDiscoveryStarted(Registry registry,
                                                     RemoteDevice device) {
                System.out.println(
                        "Discovery started: " + device.getDisplayString()
                );
            }

            public void remoteDeviceDiscoveryFailed(Registry registry,
                                                    RemoteDevice device,
                                                    Exception ex) {
                System.out.println(
                        "Discovery failed: " + device.getDisplayString() + " => " + ex
                );
            }

            public void remoteDeviceAdded(Registry registry, RemoteDevice device) {
                System.out.println(
                        "Remote device available: " + device.getDisplayString()
                );
            }

            public void remoteDeviceUpdated(Registry registry, RemoteDevice device) {
                System.out.println(
                        "Remote device updated: " + device.getDisplayString()
                );
            }

            public void remoteDeviceRemoved(Registry registry, RemoteDevice device) {
                System.out.println(
                        "Remote device removed: " + device.getDisplayString()
                );
            }

            public void localDeviceAdded(Registry registry, LocalDevice device) {
                System.out.println(
                        "Local device added: " + device.getDisplayString()
                );
            }

            public void localDeviceRemoved(Registry registry, LocalDevice device) {
                System.out.println(
                        "Local device removed: " + device.getDisplayString()
                );
            }

            public void beforeShutdown(Registry registry) {
                System.out.println(
                        "Before shutdown, the registry has devices: "
                        + registry.getDevices().size()
                );
            }

            public void afterShutdown() {
                System.out.println("Shutdown of registry complete!");

            }
        };

        // This will create necessary network resources for UPnP right away
        System.out.println("Starting Cling...");
        UpnpService upnpService = new UpnpServiceImpl(listener);

        // Send a search message to all devices and services, they should respond soon
        upnpService.getControlPoint().search(new STAllHeader());

        // Let's wait 10 seconds for them to respond
        System.out.println("Waiting 10 seconds before shutting down...");
        Thread.sleep(10000);

        // Release all resources and advertise BYEBYE to other UPnP devices
        System.out.println("Stopping Cling...");
        upnpService.shutdown();
    }
}

示例代码来自：http://4thline.org/projects/cling/core/manual/cling-core-manual.xhtml#chapter.GettingStarted

真的很感谢你的帮助。

Answer 1

看起来我使用的示例缺少导入语句：

import org.fourthline.cling.UpnpService;
import org.fourthline.cling.UpnpServiceImpl;

Answer 2

Maven负责处理您在pom.xml中声明的依赖项，为了解决您的问题，您应该在pom.xml中添加cling-core依赖项

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>my-app</name>
  <url>http://maven.apache.org</url>

  <repositories>
    <repository>
      <id>4thline-repo</id>
      <url>http://4thline.org/m2</url>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.fourthline.cling</groupId>
      <artifactId>cling-core</artifactId>
      <version>2.1.1</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.fourthline.cling/cling-core -->
    <dependency>
      <groupId>org.fourthline.cling</groupId>
      <artifactId>cling-core</artifactId>
      <version>2.1.1</version>
    </dependency>
  </dependencies>
</project>

用上面的内容替换你的pom.xml，看看maven下载包括所有依赖项的jar。

Maven在打包期间不包括类路径中的jar文件

2 个答案: