让Spark,Java和MongoDB协同工作

Question

类似于我的问题,但这一次是Java,而不是Python,给我带来了问题.

我已经遵循建议的步骤(据我所知),但由于我使用的是hadoop-2.6.1,我认为我应该使用旧的API,而不是示例中提到的新API.

我正在研究Ubuntu和我拥有的各种组件版本

• Spark spark-1.5.1-bin-hadoop2.6
• Hadoop hadoop-2.6.1
• Mongo 3.0.8
• 通过Maven包含Mongo-Hadoop连接器罐
• Java 1.8.0_66
• Maven 3.0.5

我的Java程序是基本的

import org.apache.spark.api.java.*;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.function.Function;
import com.mongodb.hadoop.MongoInputFormat;
import org.apache.hadoop.conf.Configuration;
import org.bson.BSONObject;

public class SimpleApp {
  public static void main(String[] args) {
    Configuration mongodbConfig = new Configuration();
    mongodbConfig.set("mongo.job.input.format", "com.mongodb.hadoop.MongoInputFormat");
    mongodbConfig.set("mongo.input.uri", "mongodb://localhost:27017/db.collection");
    SparkConf conf = new SparkConf().setAppName("Simple Application");
    JavaSparkContext sc = new JavaSparkContext(conf);
    JavaPairRDD<Object, BSONObject> documents = sc.newAPIHadoopRDD(
        mongodbConfig,            // Configuration
        MongoInputFormat.class,   // InputFormat: read from a live cluster.
        Object.class,             // Key class
        BSONObject.class          // Value class
    );
  }
}

使用Maven(mvn package)和以下pom文件构建正常

<project>
<groupId>edu.berkeley</groupId>
  <artifactId>simple-project</artifactId>
  <modelVersion>4.0.0</modelVersion>
  <name>Simple Project</name>
  <packaging>jar</packaging>
  <version>1.0</version>
  <dependencies>
    <dependency> <!-- Spark dependency -->
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-core_2.10</artifactId>
      <version>1.5.1</version>
    </dependency>
    <dependency>
        <groupId>org.mongodb</groupId>
        <artifactId>mongo-java-driver</artifactId>
        <version>3.2.0</version>
    </dependency>
    <dependency>
      <groupId>org.mongodb.mongo-hadoop</groupId>
      <artifactId>mongo-hadoop-core</artifactId>
      <version>1.4.2</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>
</project>

然后我提交罐子

/usr/local/share/spark-1.5.1-bin-hadoop2.6/bin/spark-submit --class "SimpleApp" --master local[4] target/simple-project-1.0.jar

并得到以下错误

Exception in thread "main" java.lang.NoClassDefFoundError: com/mongodb/hadoop/MongoInputFormat
    at SimpleApp.main(SimpleApp.java:18)

---

注意

我在12月18日编辑了这个问题,因为它变得过于混乱和冗长.以前的评论可能看起来无关紧要 然而,问题的背景是相同的.

Answer 1

我遇到了同样的问题，但经过大量的试验和更改，我用这段代码完成了我的工作。我正在 ubuntu 和 Java 7 上使用 netbeans 运行 Maven 项目希望这会有所帮助。

包括maven-shade-plugin是否存在任何黑白类冲突

PS：我不知道你的具体错误，但遇到了很多。并且这段代码运行完美。

   <dependencies>
              <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-sql_2.11</artifactId>
            <version>1.5.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>1.5.1</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>
        <dependency>
            <groupId>org.mongodb.mongo-hadoop</groupId>
            <artifactId>mongo-hadoop-core</artifactId>
            <version>1.4.1</version>
        </dependency>
    </dependencies>

Java代码

  Configuration conf = new Configuration();
    conf.set("mongo.job.input.format", "com.mongodb.hadoop.MongoInputFormat");
    conf.set("mongo.input.uri", "mongodb://localhost:27017/databasename.collectionname");
    SparkConf sconf = new SparkConf().setMaster("local").setAppName("Spark UM Jar");

    JavaRDD<User> UserMaster = sc.newAPIHadoopRDD(conf, MongoInputFormat.class, Object.class, BSONObject.class)
            .map(new Function<Tuple2<Object, BSONObject>, User>() {
                @Override
                public User call(Tuple2<Object, BSONObject> v1) throws Exception {
                    //return User
                }

            }