[英]Reading multiline json using Spark Dataset API
我想使用join()
方法對兩個數據集執行連接。 但是我不明白如何指定條件或聯接列名稱。
public static void main(String[] args) {
SparkSession spark = SparkSession
.builder()
.appName("Java Spark SQL basic example")
.master("spark://10.127.153.198:7077")
.getOrCreate();
List<String> list = Arrays.asList("partyId");
Dataset<Row> df = spark.read().text("C:\\Users\\phyadavi\\LearningAndDevelopment\\Spark-Demo\\data1\\alert.json");
Dataset<Row> df2 = spark.read().text("C:\\Users\\phyadavi\\LearningAndDevelopment\\Spark-Demo\\data1\\contract.json");
df.join(df2,JavaConversions.asScalaBuffer(list)).show();
// df.join(df2, "partyId").show();
}
當我執行以上代碼時,出現此錯誤
Exception in thread "main" org.apache.spark.sql.AnalysisException: USING column `partyId` cannot be resolved on the left side of the join. The left-side columns: [value];
at org.apache.spark.sql.catalyst.analysis.Analyzer$$anonfun$90$$anonfun$apply$56.apply(Analyzer.scala:1977)
at org.apache.spark.sql.catalyst.analysis.Analyzer$$anonfun$90$$anonfun$apply$56.apply(Analyzer.scala:1977)
at scala.Option.getOrElse(Option.scala:121)
at org.apache.spark.sql.catalyst.analysis.Analyzer$$anonfun$90.apply(Analyzer.scala:1976)
at org.apache.spark.sql.catalyst.analysis.Analyzer$$anonfun$90.apply(Analyzer.scala:1975)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.Iterator$class.foreach(Iterator.scala:893)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1336)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at org.apache.spark.sql.catalyst.analysis.Analyzer.org$apache$spark$sql$catalyst$analysis$Analyzer$$commonNaturalJoinProcessing(Analyzer.scala:1975)
at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveNaturalAndUsingJoin$$anonfun$apply$31.applyOrElse(Analyzer.scala:1961)
at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveNaturalAndUsingJoin$$anonfun$apply$31.applyOrElse(Analyzer.scala:1958)
at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan$$anonfun$resolveOperators$1.apply(LogicalPlan.scala:61)
at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan$$anonfun$resolveOperators$1.apply(LogicalPlan.scala:61)
at org.apache.spark.sql.catalyst.trees.CurrentOrigin$.withOrigin(TreeNode.scala:70)
at org.apache.spark.sql.catalyst.plans.logical.LogicalPlan.resolveOperators(LogicalPlan.scala:60)
at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveNaturalAndUsingJoin$.apply(Analyzer.scala:1958)
at org.apache.spark.sql.catalyst.analysis.Analyzer$ResolveNaturalAndUsingJoin$.apply(Analyzer.scala:1957)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1$$anonfun$apply$1.apply(RuleExecutor.scala:85)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1$$anonfun$apply$1.apply(RuleExecutor.scala:82)
at scala.collection.LinearSeqOptimized$class.foldLeft(LinearSeqOptimized.scala:124)
at scala.collection.immutable.List.foldLeft(List.scala:84)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1.apply(RuleExecutor.scala:82)
at org.apache.spark.sql.catalyst.rules.RuleExecutor$$anonfun$execute$1.apply(RuleExecutor.scala:74)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.apache.spark.sql.catalyst.rules.RuleExecutor.execute(RuleExecutor.scala:74)
at org.apache.spark.sql.execution.QueryExecution.analyzed$lzycompute(QueryExecution.scala:64)
at org.apache.spark.sql.execution.QueryExecution.analyzed(QueryExecution.scala:62)
at org.apache.spark.sql.execution.QueryExecution.assertAnalyzed(QueryExecution.scala:50)
at org.apache.spark.sql.Dataset$.ofRows(Dataset.scala:63)
at org.apache.spark.sql.Dataset.org$apache$spark$sql$Dataset$$withPlan(Dataset.scala:2822)
at org.apache.spark.sql.Dataset.join(Dataset.scala:775)
at org.apache.spark.sql.Dataset.join(Dataset.scala:748)
at com.cisco.cdx.batch.JsonDataReader.main(JsonDataReader.java:27)
這兩個JSON都有“ partyId”列。 請幫忙。
數據:
這兩個JSON都有“ partyId”列。 但是,當我同時加入兩個數據集時,spark無法找到該列。 我在這里想念什么嗎?
Alerts.json
{
"sourcePartyId": "SmartAccount_700001",
"sourceSubPartyId": "",
"partyId": "700001",
"managedndjn": "BIZ_KEY_999001",
"neAlert": {
"data1": [{
"sni": "c1f44bb6-e429-11e7-9afc-64609ee945d1",
}],
"daa2": [{
"sni": "c1f44bb6-e429-11e7-9afc-64609ee945d1",
}],
"data3": [{
"sni": "c1f44bb6-e429-11e7-9afc-64609ee945d1",
"ndjn": "999001",
}],
"advisory": [{
"sni": "c1f44bb6-e429-11e7-9afc-64609ee945d1",
"ndjn": "999001",
}]
}
}
Contracts.json
{
"sourceSubPartyId": "",
"partyId": "700001",
"neContract": {
"serialNumber": "FCH2013V245",
"productId": "FS4000-K9",
"coverageInfo": [
{
"billToCity": "Delhi",
"billToCountry": "India",
"billToPostalCode": "260001",
"billToProvince": "",
"slaCode": "1234",
}
]
}
}
但是,當我閱讀下面的方法時,我能夠打印數據。
JavaRDD<Tuple2<String, String>> javaRDD = spark.sparkContext().wholeTextFiles("C:\\\\Users\\\\phyadavi\\\\LearningAndDevelopment\\\\Spark-Demo\\\\data1\\\\alert.json", 1).toJavaRDD();
List<Tuple2<String, String>> collect = javaRDD.collect();
collect.forEach(x -> {
System.out.println(x._1);
System.out.println(x._2);
});
問題是您嘗試使用spark.read().text()
讀取為文本文件
如果您想直接將json
文件讀取到數據幀,則需要使用
spark.read().json()
如果數據是多行的,那么您需要添加以下選項:
spark.read.option("multiline", "true").json()
這就是為什么你不能夠訪問在列join
另一種方法是讀取為文本文件並將其轉換為JSON
val jsonRDD = sc.wholeTextFiles("path to json").map(x => x._2)
spark.sqlContext.read.json(jsonRDD)
.show(false)
使JSON單行顯示后,該問題得以解決。 因此,我想發表我的答案。
public class JsonDataReader {
public static void main(String[] args) {
SparkSession spark = SparkSession.builder().appName("Java Spark SQL basic example")
.master("spark://192.168.0.2:7077").getOrCreate();
// JavaRDD<Tuple2<String, String>> javaRDD = spark.sparkContext().wholeTextFiles("C:\\\\Users\\\\phyadavi\\\\LearningAndDevelopment\\\\Spark-Demo\\\\data1\\\\alert.json", 1).toJavaRDD();
Seq<String> joinColumns = scala.collection.JavaConversions
.asScalaBuffer(Arrays.asList("partyId","sourcePartyId", "sourceSubPartyId", "wfid", "generatedAt", "collectorId"));
Dataset<Row> df = spark.read().option("multiLine",true).option("mode", "PERMISSIVE")
.json("C:\\Users\\phyadavi\\LearningAndDevelopment\\Spark-Demo\\data1\\alert.json");
Dataset<Row> df2 = spark.read().option("multiLine", true).option("mode", "PERMISSIVE")
.json("C:\\Users\\phyadavi\\LearningAndDevelopment\\Spark-Demo\\data1\\contract.json");
Dataset<Row> finalDS = df.join(df2, joinColumns,"inner");
finalDS.write().mode(SaveMode.Overwrite).json("C:\\Users\\phyadavi\\LearningAndDevelopment\\Spark-Demo\\data1\\final.json");
// List<Tuple2<String, String>> collect = javaRDD.collect();
// collect.forEach(x -> {
// System.out.println(x._1);
// System.out.println(x._2);
// });
}
}
但是,@ ShankarKoiralas的答案更為精確,並且為我工作。 因此,接受了答案。
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