Apache spark sparksql中使用的嵌套javabean
我正在使用Spark 2.1,并希望编写一个人员列表作为数据框架 人:Apache spark sparksql中使用的嵌套javabean,apache-spark,Apache Spark,我正在使用Spark 2.1,并希望编写一个人员列表作为数据框架 人: public class Person { private String name; private Address address; public String getName() { return name; } public void setName(String name) { this.name = name; } pub
public class Person {
private String name;
private Address address;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
}
地址:
public class Address {
private String city;
private String street;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
}
我使用以下代码创建一个针对列表[Person]的数据帧
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import java.util.ArrayList;
import java.util.List;
public class PersonTest {
public static void main(String[] args) {
Person p = new Person();
p.setName("Tom");
Address address = new Address();
address.setCity("C");
address.setStreet("001");
p.setAddress(address);
List<Person> persons = new ArrayList<Person>();
persons.add(p);
SparkSession session = SparkSession.builder().master("local").appName("abc").enableHiveSupport().getOrCreate();
Dataset<Row> df = session.createDataFrame(persons, Person.class);
df.printSchema();
df.write().json("file:///D:/applog/spark/" + System.currentTimeMillis());
}
}
您可以创建类型化数据集,然后根据需要将其转换为数据帧:
Dataset ds=session.createDataset(persons,Encoders.bean(Person.class));
数据集df=ds.toDF();
我发现这个博客可以帮助youThanks@FrancoceingC。这是一种可行的方法,感谢您了解在没有json hackDataset df=session.createDataFrame(persons,Person.class)的情况下这是否可行代码>不正确。它应该是Dataset df=session.createDataFrame(persons,Person.class)代码>你可以通过@zman0900看到答案
Exception in thread "main" scala.MatchError: com.Address@1e5eb20a (of class com..Address)
at org.apache.spark.sql.catalyst.CatalystTypeConverters$StructConverter.toCatalystImpl(CatalystTypeConverters.scala:236)
at org.apache.spark.sql.catalyst.CatalystTypeConverters$StructConverter.toCatalystImpl(CatalystTypeConverters.scala:231)
at org.apache.spark.sql.catalyst.CatalystTypeConverters$CatalystTypeConverter.toCatalyst(CatalystTypeConverters.scala:103)
at org.apache.spark.sql.catalyst.CatalystTypeConverters$$anonfun$createToCatalystConverter$2.apply(CatalystTypeConverters.scala:383)
at org.apache.spark.sql.SQLContext$$anonfun$beansToRows$1$$anonfun$apply$1.apply(SQLContext.scala:1113)
at org.apache.spark.sql.SQLContext$$anonfun$beansToRows$1$$anonfun$apply$1.apply(SQLContext.scala:1113)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.mutable.ArrayOps$ofRef.map(ArrayOps.scala:186)
at org.apache.spark.sql.SQLContext$$anonfun$beansToRows$1.apply(SQLContext.scala:1113)
at org.apache.spark.sql.SQLContext$$anonfun$beansToRows$1.apply(SQLContext.scala:1111)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:409)
at scala.collection.Iterator$class.toStream(Iterator.scala:1322)
at scala.collection.AbstractIterator.toStream(Iterator.scala:1336)
at scala.collection.TraversableOnce$class.toSeq(TraversableOnce.scala:298)
at scala.collection.AbstractIterator.toSeq(Iterator.scala:1336)
at org.apache.spark.sql.SparkSession.createDataFrame(SparkSession.scala:380)