intellij idea 配置spark环境遇到的两个问题

在配置spark环境的时候出现两个问题：

1. pom.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<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>com.spark.zwh</groupId>
<artifactId>spark-test</artifactId>
<version>1.0-SNAPSHOT</version>

<properties>
    <spark.version>2.4.0</spark.version>
    <scala.version>2.11</scala.version>
</properties>


<dependencies>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-core_${scala.version}</artifactId>
        <version>${spark.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-streaming_${scala.version}</artifactId>
        <version>${spark.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-sql_${scala.version}</artifactId>
        <version>${spark.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-hive_${scala.version}</artifactId>
        <version>${spark.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-mllib_${scala.version}</artifactId>
        <version>${spark.version}</version>
    </dependency>

</dependencies>

<build>
    <plugins>

        <plugin>
            <groupId>org.scala-tools</groupId>
            <artifactId>maven-scala-plugin</artifactId>
            <version>2.15.2</version>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.6.0</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <configuration>
                <skip>true</skip>
            </configuration>
        </plugin>

    </plugins>
</build>

</project>

其中<spark.version>2.4.0</spark.version>
<scala.version>2.11</scala.version>
在http://spark.apache.org/downl...：
groupId: org.apache.spark
artifactId: spark-core_2.11
version: 2.4.0
其中2.11为scala版本，2.4.0为spark版本，只有相互对应的版本才能正确编译，否则会出现各种奇怪问题。

1. 配置好了却发现右键没有新建scala class选项，查了很多都没有说到点子上，最终发现

右键项目-》add frameworks support->scala->ok。现在有scala class选项了。