package com.github.boneill42;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.javaFunctions;
import java.io.Serializable;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.UUID;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.Function;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFlatMapFunction;
import scala.Tuple2;
import com.datastax.driver.core.Session;
import com.datastax.spark.connector.cql.CassandraConnector;
import com.github.boneill42.dao.ProductRowReader.ProductRowReaderFactory;
import com.github.boneill42.dao.ProductRowWriter.ProductRowWriterFactory;
import com.github.boneill42.dao.SaleRowReader.SaleRowReaderFactory;
import com.github.boneill42.dao.SaleRowWriter.SaleRowWriterFactory;
import com.github.boneill42.dao.SummaryRowReader.SummaryRowReaderFactory;
import com.github.boneill42.dao.SummaryRowWriter.SummaryRowWriterFactory;
import com.github.boneill42.model.Product;
import com.github.boneill42.model.Sale;
import com.github.boneill42.model.Summary;
import com.google.common.base.Optional;
public class JavaDemo implements Serializable {
private static final long serialVersionUID = 1L;
private transient SparkConf conf;
private ProductRowWriterFactory productWriter = new ProductRowWriterFactory();
private ProductRowReaderFactory productReader = new ProductRowReaderFactory();
private SaleRowReaderFactory saleReader = new SaleRowReaderFactory();
private SaleRowWriterFactory saleWriter = new SaleRowWriterFactory();
private SummaryRowReaderFactory summaryReader = new SummaryRowReaderFactory();
private SummaryRowWriterFactory summaryWriter = new SummaryRowWriterFactory();
private JavaDemo(SparkConf conf) {
this.conf = conf;
}
private void run() {
JavaSparkContext sc = new JavaSparkContext(conf);
generateData(sc);
compute(sc);
showResults(sc);
sc.stop();
}
@SuppressWarnings("serial")
private void generateData(JavaSparkContext sc) {
CassandraConnector connector = CassandraConnector.apply(sc.getConf());
// Prepare the schema
try (Session session = connector.openSession()) {
session.execute("DROP KEYSPACE IF EXISTS java_api");
session.execute("CREATE KEYSPACE java_api WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1}");
session.execute("CREATE TABLE java_api.products (id INT PRIMARY KEY, name TEXT, parents LIST<INT>)");
session.execute("CREATE TABLE java_api.sales (id UUID PRIMARY KEY, product INT, price DECIMAL)");
session.execute("CREATE TABLE java_api.summaries (product INT PRIMARY KEY, summary DECIMAL)");
}
// Prepare the products hierarchy
List<Product> products = Arrays.asList(
new Product(0, "All products", Collections.<Integer>emptyList()),
new Product(1, "Product A", Arrays.asList(0)),
new Product(4, "Product A1", Arrays.asList(0, 1)),
new Product(5, "Product A2", Arrays.asList(0, 1)),
new Product(2, "Product B", Arrays.asList(0)),
new Product(6, "Product B1", Arrays.asList(0, 2)),
new Product(7, "Product B2", Arrays.asList(0, 2)),
new Product(3, "Product C", Arrays.asList(0)),
new Product(8, "Product C1", Arrays.asList(0, 3)),
new Product(9, "Product C2", Arrays.asList(0, 3))
);
JavaRDD<Product> productsRDD = sc.parallelize(products);
javaFunctions(productsRDD).writerBuilder("java_api", "products", productWriter).saveToCassandra();
JavaRDD<Sale> salesRDD = productsRDD.filter(new Function<Product, Boolean>() {
@Override
public Boolean call(Product product) throws Exception {
return product.getParents().size() == 2;
}
}).flatMap(new FlatMapFunction<Product, Sale>() {
@Override
public Iterable<Sale> call(Product product) throws Exception {
Random random = new Random();
List<Sale> sales = new ArrayList<>(1000);
for (int i = 0; i < 1000; i++) {
sales.add(new Sale(UUID.randomUUID(), product.getId(), BigDecimal.valueOf(random.nextDouble())));
}
return sales;
}
});
javaFunctions(salesRDD).writerBuilder("java_api", "sales", saleWriter).saveToCassandra();
}
@SuppressWarnings("serial")
private void compute(JavaSparkContext sc) {
JavaPairRDD<Integer, Product> productsRDD = javaFunctions(sc)
.cassandraTable("java_api", "products", productReader)
.keyBy(new Function<Product, Integer>() {
@Override
public Integer call(Product product) throws Exception {
return product.getId();
}
});
JavaPairRDD<Integer, Sale> salesRDD = javaFunctions(sc)
.cassandraTable("java_api", "sales", saleReader)
.keyBy(new Function<Sale, Integer>() {
@Override
public Integer call(Sale sale) throws Exception {
return sale.getProduct();
}
});
JavaPairRDD<Integer, Tuple2<Sale, Product>> joinedRDD = salesRDD.join(productsRDD);
JavaPairRDD<Integer, BigDecimal> allSalesRDD = joinedRDD.flatMapToPair(new PairFlatMapFunction<Tuple2<Integer, Tuple2<Sale, Product>>, Integer, BigDecimal>() {
@Override
public Iterable<Tuple2<Integer, BigDecimal>> call(Tuple2<Integer, Tuple2<Sale, Product>> input) throws Exception {
Tuple2<Sale, Product> saleWithProduct = input._2();
List<Tuple2<Integer, BigDecimal>> allSales = new ArrayList<>(saleWithProduct._2().getParents().size() + 1);
allSales.add(new Tuple2<>(saleWithProduct._1().getProduct(), saleWithProduct._1().getPrice()));
for (Integer parentProduct : saleWithProduct._2().getParents()) {
allSales.add(new Tuple2<>(parentProduct, saleWithProduct._1().getPrice()));
}
return allSales;
}
});
JavaRDD<Summary> summariesRDD = allSalesRDD.reduceByKey(new Function2<BigDecimal, BigDecimal, BigDecimal>() {
@Override
public BigDecimal call(BigDecimal v1, BigDecimal v2) throws Exception {
return v1.add(v2);
}
}).map(new Function<Tuple2<Integer, BigDecimal>, Summary>() {
@Override
public Summary call(Tuple2<Integer, BigDecimal> input) throws Exception {
return new Summary(input._1(), input._2());
}
});
javaFunctions(summariesRDD).writerBuilder("java_api", "summaries", summaryWriter).saveToCassandra();
}
@SuppressWarnings("serial")
private void showResults(JavaSparkContext sc) {
JavaPairRDD<Integer, Summary> summariesRdd = javaFunctions(sc)
.cassandraTable("java_api", "summaries", summaryReader)
.keyBy(new Function<Summary, Integer>() {
@Override
public Integer call(Summary summary) throws Exception {
return summary.getProduct();
}
});
JavaPairRDD<Integer, Product> productsRdd = javaFunctions(sc)
.cassandraTable("java_api", "products", productReader)
.keyBy(new Function<Product, Integer>() {
@Override
public Integer call(Product product) throws Exception {
return product.getId();
}
});
List<Tuple2<Product, Optional<Summary>>> results = productsRdd.leftOuterJoin(summariesRdd).values().toArray();
for (Tuple2<Product, Optional<Summary>> result : results) {
System.out.println(result);
}
}
public static void main(String[] args) {
if (args.length != 2) {
System.err.println("Syntax: com.datastax.spark.demo.JavaDemo <Spark Master URL> <Cassandra contact point>");
System.exit(1);
}
SparkConf conf = new SparkConf();
conf.setAppName("Java API demo");
conf.setMaster(args[0]);
conf.set("spark.cassandra.connection.host", args[1]);
JavaDemo app = new JavaDemo(conf);
app.run();
}
}
