Auto Compile在Eclipse-maven-Scala项目中不起作用

Question

我正在研究我在Eclipse中创建的scala项目。我改变scala文件时，它没有反映出它是＆＃34;错误：无法找到或加载主类com.sparkscala.MainExample＆＃34;但是当我建立它成功的时候。

pom.xml配置：

<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.spark-scala</groupId>
    <artifactId>spark-scala</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>${project.artifactId}</name>
    <description>Spark in Scala</description>
    <inceptionYear>2010</inceptionYear>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <encoding>UTF-8</encoding>
        <scala.tools.version>2.10</scala.tools.version>
        <!-- Put the Scala version of the cluster -->
        <scala.version>2.10.4</scala.version>
    </properties>

    <!-- repository to add org.apache.spark -->
    <repositories>
        <repository>
            <id>cloudera-repo-releases</id>
            <url>https://repository.cloudera.com/artifactory/repo/</url>
        </repository>
    </repositories>

    <build>
        <sourceDirectory>src/main/scala</sourceDirectory>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <!-- see http://davidb.github.com/scala-maven-plugin -->
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.1</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <args>
                                <arg>-make:transitive</arg>
                                <arg>-dependencyfile</arg>
                                <arg>${project.build.directory}/.scala_dependencies</arg>
                            </args>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.13</version>
                <configuration>
                    <useFile>false</useFile>
                    <disableXmlReport>true</disableXmlReport>
                    <includes>
                        <include>**/*Test.*</include>
                        <include>**/*Suite.*</include>
                    </includes>
                </configuration>
            </plugin>

            <!-- "package" command plugin -->
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.4.1</version>
                <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>
                <groupId>org.scala-tools</groupId>
                <artifactId>maven-scala-plugin</artifactId>
                <executions>
                    <execution>
                        <id>scala-compile-first</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>add-source</goal>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>scala-test-compile</id>
                        <phase>process-test-resources</phase>
                        <goals>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <!-- Scala and Spark dependencies -->
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.10</artifactId>
            <version>1.2.0-cdh5.3.1</version>
        </dependency>

    </dependencies>
</project>

Answer 1

这很复杂 Scala编译器速度慢且令人毛骨悚然。它将运行最后一个好的编译文件，而不是清楚地告诉你麻烦。因此，如果您正在进行println（“Hello World”），请尝试更改为“Hello Something Else”以查看实际是否正在进行编译，或者IDE只是选择最后一个好的编译文件。
另外你的pom.xml不正确。 我建议去Eclipse的Windows - ＆gt;显示视图 - ＆gt;问题..你肯定有一些问题。先删除它们。清洁，建造并再次运行 如果要使用Spark，则必须确保Scala版本与Eclipse项目构建路径中的版本匹配。 这是一个很好的pom.xml，正确版本的Spark是唯一的依赖项。无需添加Scala库依赖项，因为它已包含在Spark依赖关系层次结构中。另外，确保Eclipse项目构建路径中的Scala库版本与我在pom.xml中提供的版本匹配，即2.11.x＆gt;＆gt;

<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.spark-scala</groupId>
    <artifactId>spark-scala</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>${project.artifactId}</name>
    <description>Spark in Scala</description>
    <inceptionYear>2010</inceptionYear>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <encoding>UTF-8</encoding>
        <scala.tools.version>2.10</scala.tools.version>
        <!-- Put the Scala version of the cluster -->
        <scala.version>2.10.4</scala.version>
    </properties>

    <!-- repository to add org.apache.spark -->
    <repositories>
        <repository>
            <id>cloudera-repo-releases</id>
            <url>https://repository.cloudera.com/artifactory/repo/</url>
        </repository>
    </repositories>

    <build>
        <sourceDirectory>src/main/scala</sourceDirectory>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <!-- see http://davidb.github.com/scala-maven-plugin -->
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.1</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.13</version>
                <configuration>
                    <useFile>false</useFile>
                    <disableXmlReport>true</disableXmlReport>
                    <includes>
                        <include>**/*Test.*</include>
                        <include>**/*Suite.*</include>
                    </includes>
                </configuration>
            </plugin>

            <!-- "package" command plugin -->
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.4.1</version>
                <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>
                <groupId>org.scala-tools</groupId>
                <artifactId>maven-scala-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>1.2.1</version>
        </dependency>
    </dependencies>
</project>