嘗試運行vertx應用時發生ClassNotFoundException

Question

我正在嘗試使用以下代碼運行示例Vert.x程序：

public class MyFirstVerticle extends AbstractVerticle {

  @Override
  public void start(Future<Void> fut) {
    vertx
        .createHttpServer()
        .requestHandler(r -> {
          r.response().end("<h1>Hello from my first " +
              "Vert.x 3 application</h1>");
        })
        .listen(8080, result -> {
          if (result.succeeded()) {
            fut.complete();
          } else {
            fut.fail(result.cause());
          }
        });
  }
}

下面是Maven pom文件：

<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>io.vertx.blog</groupId>
    <artifactId>MyFirstVertxMicroservices</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>io.vertx</groupId>
            <artifactId>vertx-core</artifactId>
            <version>3.3.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.4</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/io.netty/netty-handler -->
        <!-- <dependency> <groupId>io.netty</groupId> <artifactId>netty-handler</artifactId>
            <version>4.0.33.Final</version> </dependency> -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>io.vertx</groupId>
            <artifactId>vertx-unit</artifactId>
            <version>3.0.0</version>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>com.fasterxml.jackson.core</groupId>
                        <artifactId>jackson-databind</artifactId>
                        <version>2.9.4</version>
                    </dependency>
                </dependencies>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.3</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <manifestEntries>
                                        <Main-Class>io.vertx.core.Starter</Main-Class>
                                        <Main-Verticle>com.inet.vertex.verticle.MyFirstVerticle</Main-Verticle>
                                    </manifestEntries>
                                </transformer>
                            </transformers>
                            <artifactSet/>
                            <outputFile>${project.build.directory}/${project.artifactId}-${project.version}-fat.jar</outputFile>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

        </plugins>
    </build>

</project>

當我嘗試使用以下命令運行程序時：

java -jar target/MyFirstVertxMicroservices-1.0-SNAPSHOT-fat.jar

我收到以下錯誤：

SEVERE: Failed in deploying verticle
java.lang.ClassNotFoundException: com.inet.vertex.verticle.MyFirstVerticle
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)

我嘗試解壓縮胖子jar文件，可以看到MyfirstVerticle.class位於文件夾com / inet / vertex / verticle / MyfirstVerticle.class內 。

我想念什么嗎？

Answer 1

假設它是Java項目的標准目錄結構。

更新您的Pom以匹配Vert.X示例pom。 https://github.com/vert-x3/vertx-examples/blob/master/maven-verticles/maven-verticle/pom.xml

特別是陰影插件部分。 您缺少AppendingTransformer部分。

   <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>2.3</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <transformers>
                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                  <manifestEntries>
                    <Main-Class>io.vertx.core.Launcher</Main-Class>
                    <Main-Verticle>${main.verticle}</Main-Verticle>
                  </manifestEntries>
                </transformer>
                <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                  <resource>META-INF/services/io.vertx.core.spi.VerticleFactory</resource>
                </transformer>
              </transformers>
              <artifactSet>
              </artifactSet>
              <outputFile>${project.build.directory}/${project.artifactId}-${project.version}-fat.jar</outputFile>
            </configuration>
          </execution>
        </executions>
      </plugin>