将 Spring 与 Spark 一起使用

Question

我正在开发一个 Spark 应用程序，并且我习惯于将 Spring 作为依赖注入框架。现在我遇到了一个问题，处理部分使用了 Spring 的 @Autowired 功能，但它是由 Spark 序列化和反序列化的。

所以下面的代码给我带来了麻烦：

Processor processor = ...; // This is a Spring constructed object
                           // and makes all the trouble
JavaRDD<Txn> rdd = ...; // some data for Spark
rdd.foreachPartition(processor);

处理器看起来像这样：

public class Processor implements VoidFunction<Iterator<Txn>>, Serializeable {
    private static final long serialVersionUID = 1L;

    @Autowired // This will not work if the object is deserialized
    private transient DatabaseConnection db;

    @Override
    public void call(Iterator<Txn> txns) {
        ... // do some fance stuff
        db.store(txns);
    }
}

所以我的问题是：是否可以将 Spring 与 Spark 结合使用？如果不是，那么做这样的事情最优雅的方式是什么？任何帮助表示赞赏！

Answer 1

来自提问者：添加：要直接干扰反序列化部分而不修改您自己的类，请使用以下spring-spark project by parapluplu。这个项目会在你的 bean 被 spring 反序列化时自动装配它。

---

编辑：

要使用 Spark，您需要进行以下设置（也可以在 this repository 中看到）：

• Spring Boot + Spark：

.

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.2.RELEASE</version>
    <relativePath/>
    <!-- lookup parent from repository -->
</parent>

...

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.11 -->
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-core_2.11</artifactId>
        <version>2.1.0</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
            <exclusion>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql_2.11 -->
    <dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-sql_2.11</artifactId>
        <version>2.1.0</version>
    </dependency>

    <!-- fix java.lang.ClassNotFoundException: org.codehaus.commons.compiler.UncheckedCompileException -->
    <dependency>
        <groupId>org.codehaus.janino</groupId>
        <artifactId>commons-compiler</artifactId>
        <version>2.7.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.slf4j/log4j-over-slf4j -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>log4j-over-slf4j</artifactId>
        <version>1.7.25</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.7.5</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.6.4</version>
    </dependency>

</dependencies>

然后你需要应用程序类，就像 Spring Boot 一样：

@SpringBootApplication
public class SparkExperimentApplication {

    public static void main(String[] args) {
        SpringApplication.run(SparkExperimentApplication.class, args);
    }
}

然后是一个将它们绑定在一起的配置

@Configuration
@PropertySource("classpath:application.properties")
public class ApplicationConfig {

    @Autowired
    private Environment env;

    @Value("${app.name:jigsaw}")
    private String appName;

    @Value("${spark.home}")
    private String sparkHome;

    @Value("${master.uri:local}")
    private String masterUri;

    @Bean
    public SparkConf sparkConf() {
        SparkConf sparkConf = new SparkConf()
                .setAppName(appName)
                .setSparkHome(sparkHome)
                .setMaster(masterUri);

        return sparkConf;
    }

    @Bean
    public JavaSparkContext javaSparkContext() {
        return new JavaSparkContext(sparkConf());
    }

    @Bean
    public SparkSession sparkSession() {
        return SparkSession
                .builder()
                .sparkContext(javaSparkContext().sc())
                .appName("Java Spark SQL basic example")
                .getOrCreate();
    }

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }
}

那么就可以使用SparkSession类与Spark SQL进行通信了：

/**
 * Created by achat1 on 9/23/15.
 * Just an example to see if it works.
 */
@Component
public class WordCount {
    @Autowired
    private SparkSession sparkSession;

    public List<Count> count() {
        String input = "hello world hello hello hello";
        String[] _words = input.split(" ");
        List<Word> words = Arrays.stream(_words).map(Word::new).collect(Collectors.toList());
        Dataset<Row> dataFrame = sparkSession.createDataFrame(words, Word.class);
        dataFrame.show();
        //StructType structType = dataFrame.schema();

        RelationalGroupedDataset groupedDataset = dataFrame.groupBy(col("word"));
        groupedDataset.count().show();
        List<Row> rows = groupedDataset.count().collectAsList();//JavaConversions.asScalaBuffer(words)).count();
        return rows.stream().map(new Function<Row, Count>() {
            @Override
            public Count apply(Row row) {
                return new Count(row.getString(0), row.getLong(1));
            }
        }).collect(Collectors.toList());
    }
}

参考这两个类：

public class Word {
    private String word;

    public Word() {
    }

    public Word(String word) {
        this.word = word;
    }

    public void setWord(String word) {
        this.word = word;
    }

    public String getWord() {
        return word;
    }
}

public class Count {
    private String word;
    private long count;

    public Count() {
    }

    public Count(String word, long count) {
        this.word = word;
        this.count = count;
    }

    public String getWord() {
        return word;
    }

    public void setWord(String word) {
        this.word = word;
    }

    public long getCount() {
        return count;
    }

    public void setCount(long count) {
        this.count = count;
    }
}

然后你可以运行看看它返回了正确的数据：

@RequestMapping("api")
@Controller
public class ApiController {
    @Autowired
    WordCount wordCount;

    @RequestMapping("wordcount")
    public ResponseEntity<List<Count>> words() {
        return new ResponseEntity<>(wordCount.count(), HttpStatus.OK);
    }
}

说

[{"word":"hello","count":4},{"word":"world","count":1}]