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James Lee
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split TypedDataset
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+94
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‎src/main/java/com/sparkTutorial/sparkSql/RddToDataset.java

Lines changed: 53 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,53 @@
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package com.sparkTutorial.sparkSql;
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import org.apache.log4j.Level;
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import org.apache.log4j.Logger;
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import org.apache.spark.SparkConf;
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import org.apache.spark.api.java.JavaRDD;
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import org.apache.spark.api.java.JavaSparkContext;
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import org.apache.spark.sql.Dataset;
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import org.apache.spark.sql.Encoders;
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import org.apache.spark.sql.SparkSession;
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public class RddToDataset {
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private static final String COMMA_DELIMITER = ",(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
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public static void main(String[] args) throws Exception {
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Logger.getLogger("org").setLevel(Level.ERROR);
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SparkConf conf = new SparkConf().setAppName("StackOverFlowSurvey").setMaster("local[1]");
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JavaSparkContext sc = new JavaSparkContext(conf);
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SparkSession session = SparkSession.builder().appName("StackOverFlowSurvey").master("local[1]").getOrCreate();
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JavaRDD<String> lines = sc.textFile("in/2016-stack-overflow-survey-responses.csv");
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JavaRDD<Response> responseRDD = lines
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.filter(line -> !line.split(COMMA_DELIMITER, -1)[2].equals("country"))
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.map(line -> {
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String[] splits = line.split(COMMA_DELIMITER, -1);
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return new Response(splits[2], convertStringToFloat(splits[6]), splits[9], convertStringToFloat(splits[14]));
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});
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Dataset<Response> responseDataset = session.createDataset(responseRDD.rdd(), Encoders.bean(Response.class));
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System.out.println("=== Print out schema ===");
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responseDataset.printSchema();
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System.out.println("=== Print 20 records of responses table ===");
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responseDataset.show(20);
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JavaRDD<Response> responseJavaRDD = responseDataset.toJavaRDD();
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for (Response response : responseJavaRDD.collect()) {
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System.out.println(response);
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}
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}
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private static Integer convertStringToFloat(String split) {
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return split.isEmpty() ? null : Math.round(Float.valueOf(split));
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}
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}

‎src/main/java/com/sparkTutorial/sparkSql/Response.java

Lines changed: 18 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -4,11 +4,11 @@
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public class Response implements Serializable {
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private String country;
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private float ageMidPoint;
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private Integer ageMidPoint;
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private String occupation;
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private float salaryMidPoint;
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private Integer salaryMidPoint;
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public Response(String country, float ageMidPoint, String occupation, float salaryMidPoint) {
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public Response(String country, Integer ageMidPoint, String occupation, Integer salaryMidPoint) {
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this.country = country;
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this.ageMidPoint = ageMidPoint;
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this.occupation = occupation;
@@ -26,11 +26,11 @@ public void setCountry(String country) {
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this.country = country;
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}
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public float getAgeMidPoint() {
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public Integer getAgeMidPoint() {
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return ageMidPoint;
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}
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public void setAgeMidPoint(float ageMidPoint) {
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public void setAgeMidPoint(Integer ageMidPoint) {
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this.ageMidPoint = ageMidPoint;
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}
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@@ -42,11 +42,22 @@ public void setOccupation(String occupation) {
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this.occupation = occupation;
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}
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public float getSalaryMidPoint() {
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public Integer getSalaryMidPoint() {
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return salaryMidPoint;
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}
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public void setSalaryMidPoint(float salaryMidPoint) {
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public void setSalaryMidPoint(Integer salaryMidPoint) {
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this.salaryMidPoint = salaryMidPoint;
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}
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@Override
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public String toString() {
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return "Response{" +
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"country='" + country + '\'' +
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", ageMidPoint=" + ageMidPoint +
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", occupation='" + occupation + '\'' +
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", salaryMidPoint=" + salaryMidPoint +
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'}';
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}
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}

‎src/main/java/com/sparkTutorial/sparkSql/TypedDataset.java

Lines changed: 23 additions & 43 deletions
Original file line numberDiff line numberDiff line change
@@ -2,81 +2,61 @@
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import org.apache.log4j.Level;
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import org.apache.log4j.Logger;
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import org.apache.spark.SparkConf;
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import org.apache.spark.api.java.JavaRDD;
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import org.apache.spark.api.java.JavaSparkContext;
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import org.apache.spark.sql.Dataset;
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import org.apache.spark.sql.Encoders;
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import org.apache.spark.sql.SparkSession;
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import org.apache.spark.sql.*;
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import static org.apache.spark.sql.functions.avg;
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import static org.apache.spark.sql.functions.col;
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import static org.apache.spark.sql.functions.max;
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public class TypedDataset {
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private static final String AGE_MIDPOINT = "ageMidpoint";
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private static final String SALARY_MIDPOINT = "salaryMidPoint";
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private static final String SALARY_MIDPOINT_BUCKET = "salaryMidpointBucket";
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private static final float NULL_VALUE = -1.0f;
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private static final String COMMA_DELIMITER = ",(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
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public static void main(String[] args) throws Exception {
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Logger.getLogger("org").setLevel(Level.ERROR);
26-
SparkConf conf = new SparkConf().setAppName("StackOverFlowSurvey").setMaster("local[1]");
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SparkSession session = SparkSession.builder().appName("StackOverFlowSurvey").master("local[1]").getOrCreate();
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28-
JavaSparkContext sc = new JavaSparkContext(conf);
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DataFrameReader dataFrameReader = session.read();
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30-
SparkSession session = SparkSession.builder().appName("StackOverFlowSurvey").master("local[1]").getOrCreate();
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Dataset<Row> responses = dataFrameReader.option("header","true").csv("in/2016-stack-overflow-survey-responses.csv");
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32-
JavaRDD<String> lines = sc.textFile("in/2016-stack-overflow-survey-responses.csv");
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Dataset<Row> responseWithSelectedColumns = responses.select(col("country"), col("age_midpoint").as("ageMidPoint").cast("integer"), col("occupation"), col("salary_midpoint").as("salaryMidPoint").cast("integer"));
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34-
JavaRDD<Response> responseRDD = lines
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.filter(line -> !line.split(COMMA_DELIMITER, -1)[2].equals("country"))
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.map(line -> {
37-
String[] splits = line.split(COMMA_DELIMITER, -1);
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return new Response(splits[2], convertStringToFloat(splits[6]), splits[9], convertStringToFloat(splits[14]));
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});
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Dataset<Response> responseDataset = session.createDataset(responseRDD.rdd(), Encoders.bean(Response.class));
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Dataset<Response> typedDataset = responseWithSelectedColumns.as(Encoders.bean(Response.class));
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4230
System.out.println("=== Print out schema ===");
43-
responseDataset.printSchema();
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typedDataset.printSchema();
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4533
System.out.println("=== Print 20 records of responses table ===");
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responseDataset.show(20);
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typedDataset.show(20);
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System.out.println("=== Print records where the response is from Afghanistan ===");
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responseDataset.filter(response -> response.getCountry().equals("Afghanistan")).show();
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typedDataset.filter(response -> response.getCountry().equals("Afghanistan")).show();
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5139
System.out.println("=== Print the count of occupations ===");
52-
responseDataset.groupBy(responseDataset.col("occupation")).count().show();
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40+
typedDataset.groupBy(typedDataset.col("occupation")).count().show();
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5542
System.out.println("=== Print records with average mid age less than 20 ===");
56-
responseDataset.filter(response -> response.getAgeMidPoint() != NULL_VALUE && response.getAgeMidPoint() < 20).show();
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typedDataset.filter(response -> response.getAgeMidPoint() !=null && response.getAgeMidPoint() < 20).show();
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5845
System.out.println("=== Print the result with salary middle point in descending order ===");
59-
responseDataset.orderBy(responseDataset.col(SALARY_MIDPOINT ).desc()).show();
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typedDataset.orderBy(typedDataset.col(SALARY_MIDPOINT ).desc()).show();
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System.out.println("=== Group by country and aggregate by average salary middle point and max age middle point ===");
62-
responseDataset
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.filter(response -> response.getSalaryMidPoint() != NULL_VALUE)
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.groupBy("country")
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.agg(avg(SALARY_MIDPOINT), max(AGE_MIDPOINT))
66-
.show();
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typedDataset.filter(response -> response.getSalaryMidPoint() != null)
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.groupBy("country")
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.agg(avg(SALARY_MIDPOINT), max(AGE_MIDPOINT))
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.show();
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System.out.println("=== Group by salary bucket ===");
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responseDataset
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.map(response -> Math.round(response.getSalaryMidPoint()/20000) * 20000, Encoders.INT())
72-
.withColumnRenamed("value", SALARY_MIDPOINT_BUCKET)
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.groupBy(SALARY_MIDPOINT_BUCKET)
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.count()
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.orderBy(SALARY_MIDPOINT_BUCKET).show();
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typedDataset.filter(response -> response.getSalaryMidPoint() != null)
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.map(response -> Math.round(response.getSalaryMidPoint()/20000) * 20000, Encoders.INT())
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.withColumnRenamed("value", SALARY_MIDPOINT_BUCKET)
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.groupBy(SALARY_MIDPOINT_BUCKET)
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.count()
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.orderBy(SALARY_MIDPOINT_BUCKET).show();
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}
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78-
private static float convertStringToFloat(String split) {
79-
return split.isEmpty() ? NULL_VALUE : Float.valueOf(split);
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}
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}

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