Spark和Cassandra Java应用程序:线程“main”中的异常java.lang.NoClassDefFoundError:org / apache / spark / sql / Dataset [英] Spark and Cassandra Java application: Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/spark/sql/Dataset
问题描述
我得到了一个令人惊讶的siplme java应用程序,我几乎从这个例子中复制过: http://markmail.org/download.xqy?id=zua6upabiylzeetp&number=2
I got an amazingly siplme java application which I almost copied from this one example: http://markmail.org/download.xqy?id=zua6upabiylzeetp&number=2
我想做的就是阅读表数据和在Eclipse控制台中显示。
All I wanted to do is to read the table data and display in the Eclipse console.
我的pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>chat_connaction_test</groupId>
<artifactId>ChatSparkConnectionTest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>com.datastax.cassandra</groupId>
<artifactId>cassandra-driver-core</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>2.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.datastax.spark/spark-cassandra-connector_2.10 -->
<dependency>
<groupId>com.datastax.spark</groupId>
<artifactId>spark-cassandra-connector_2.10</artifactId>
<version>2.0.0-M3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-streaming_2.10 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-streaming_2.10</artifactId>
<version>2.0.0</version>
</dependency>
<!--
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-hive_2.10</artifactId>
<version>1.5.2</version>
</dependency>
-->
</dependencies>
</project>
我的java代码:
package com.chatSparkConnactionTest;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.javaFunctions;
import java.io.Serializable;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
import com.datastax.spark.connector.japi.CassandraRow;
public class JavaDemo implements Serializable {
private static final long serialVersionUID = 1L;
public static void main(String[] args) {
SparkConf conf = new SparkConf().
setAppName("chat").
setMaster("local").
set("spark.executor.memory","1g").
set("spark.cassandra.connection.host", "127.0.0.1");
JavaSparkContext sc = new JavaSparkContext(conf);
JavaRDD<String> cassandraRowsRDD = javaFunctions(sc).cassandraTable(
"chat", "dictionary")
.map(new Function<CassandraRow, String>() {
@Override
public String call(CassandraRow cassandraRow) throws Exception {
String tempResult = cassandraRow.toString();
System.out.println(tempResult);
return tempResult;
}
}
);
System.out.println("Data as CassandraRows: \n" +
cassandraRowsRDD.collect().size()); // THIS IS A LINE WITH ERROR
}
}
这里是我的错误:
16/10/05 20:49:18 INFO CassandraConnector:连接到Cassandra
集群:测试集群异常在线程main
java.lang.NoClassDefFoundError:org / apache / spark / sql / Dataset at
java.lang.Class.getDeclaredMethods0(Native Method)at
java.lang.Class .privateGetDeclaredMethods(来源不明)在
java.lang.Class.getDeclaredMethod(来源不明)在
java.io.ObjectStreamClass.getPrivateMethod(来源不明)在
java.io.ObjectStreamClass.access $ 17 $(未知来源)
java.io.ObjectStreamClass $ 2.run(未知来源)
java.io.ObjectStreamClass $ 2.run(未知来源)at
java.security.AccessController。 doBrivileged(Native Method)at
java.io.ObjectStreamClass。(Unknown Source)at
java.io.ObjectStreamClass.lookup(Unknown Source)at
java.io.Obj ectOutputStream.writeObject0(来源不明)处,在
java.io.ObjectOutputStream中的
java.io.ObjectOutputStream.writeSerialData(来源不明)
java.io.ObjectOutputStream.defaultWriteFields(来源不明)。 writeOrdinaryObject(来源不明)维持在
java.io.ObjectOutputStream.writeSerialData
java.io.ObjectOutputStream.writeObject0(来源不明)在
java.io.ObjectOutputStream.defaultWriteFields(来源不明)(来自
的
java.io.ObjectOutputStream.writeOrdinaryObject(未知来源)的未知来源
java.io.ObjectOutputStream.writeObject0(未知来源)
java.io.ObjectOutputStream.writeObject(未知来源) )
scala.collection.immutable。$ colon $ colon.writeObject(List.scala:379)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at
sun.reflect。 NativeMethodAccessorImpl.invoke(未知来源)at
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)at at at at
java.lang.ref.Method.invoke(未知来源)
java.io.ObjectStreamClass.invokeWriteObject(未知来源)at
java.io.ObjectOutputStream.writeSerialData(Unknown Source)at at
java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)at
java.io.ObjectOutputStream.writeObject0(Unknown Source)at
java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)at
$ b的java.io.ObjectOutputStream.writeSerialData(未知来源)
java.io.ObjectOutputStream.writeOrdinaryObject(未知来源)
java.io.ObjectOutputStream.writeObject0(未知来源)
java.io.ObjectOutputStream.defaultWriteFields(未知来源)at
java.io.ObjectOutputStream.writeSerialData(未知来源)at
java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)at
java。
的io.ObjectOutputStream.writeObject0(未知来源)java.io.ObjectOutputStream.defaultWriteFields(未知来源) )at
java.io.ObjectOutputStream.writeSerialData(Unknown Source)at
java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)at
java.io.ObjectOutputStream.writeObject0(Unknown Source)at at
java.io.ObjectOutputStream.writeObject(未知来源)at
org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
at
org.apache .spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
。在
$ org.apache.spark.util.ClosureCleaner .ensureSerializable(ClosureCleaner.scala:295)
。在
org.apache.spark.util.ClosureCleaner $ .org $ apache $ spark $ util $ ClosureCleaner $$ clean(ClosureCleaner.scala:288)
at
org.apache.spark.util.ClosureCleaner $ .clean(ClosureCleaner.scala:108)
at org.apache.spark.SparkContext.clean(SparkContext.scala:2037)at
org.apache.spark.SparkContext.runJob(SparkContext.scala: 1896)
org.apache.spark.SparkCo ntext.runJob(SparkContext.scala:1911)at
org.apache.spark.rdd.RDD $$ anonfun $ collect $ 1.apply(RDD.scala:893)at
org.apache.spark。 rdd.RDDOperationScope $ .withScope(RDDOperationScope.scala:151)
。在
$ org.apache.spark.rdd.RDDOperationScope .withScope(RDDOperationScope.scala:112)
。在org.apache。 spark.rdd.RDD.withScope(RDD.scala:358)at
org.apache.spark.rdd.RDD.collect(RDD.scala:892)at
org.apache.spark.api。 java.JavaRDDLike $ class.collect(JavaRDDLike.scala:360)
at
org.apache.spark.api.java.AbstractJavaRDDLike.collect(JavaRDDLike.scala:45)
at com。 chatSparkConnactionTest.JavaDemo.main(JavaDemo.java:37)导致了
。通过:抛出java.lang.ClassNotFoundException:org.apache.spark.sql.Dataset在
java.net.URLClassLoader.findClass(来源不明) at
java.lang.ClassLoader.loadClass(Unknown Source)at
sun.misc.Launcher $ AppClassLoader.loadClass(Unknown Source)at
java.lang.ClassLoader.loadCl屁股(未知来源)... 58更多
16/10/05 20:49:18 INFO CassandraConnector: Connected to Cassandra cluster: Test Cluster Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/spark/sql/Dataset at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Unknown Source) at java.lang.Class.getDeclaredMethod(Unknown Source) at java.io.ObjectStreamClass.getPrivateMethod(Unknown Source) at java.io.ObjectStreamClass.access$1700(Unknown Source) at java.io.ObjectStreamClass$2.run(Unknown Source) at java.io.ObjectStreamClass$2.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.io.ObjectStreamClass.(Unknown Source) at java.io.ObjectStreamClass.lookup(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.writeObject(Unknown Source) at scala.collection.immutable.$colon$colon.writeObject(List.scala:379) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.writeObject(Unknown Source) at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43) at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100) at org.apache.spark.util.ClosureCleaner$.ensureSerializable(ClosureCleaner.scala:295) at org.apache.spark.util.ClosureCleaner$.org$apache$spark$util$ClosureCleaner$$clean(ClosureCleaner.scala:288) at org.apache.spark.util.ClosureCleaner$.clean(ClosureCleaner.scala:108) at org.apache.spark.SparkContext.clean(SparkContext.scala:2037) at org.apache.spark.SparkContext.runJob(SparkContext.scala:1896) at org.apache.spark.SparkContext.runJob(SparkContext.scala:1911) at org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:893) at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151) at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112) at org.apache.spark.rdd.RDD.withScope(RDD.scala:358) at org.apache.spark.rdd.RDD.collect(RDD.scala:892) at org.apache.spark.api.java.JavaRDDLike$class.collect(JavaRDDLike.scala:360) at org.apache.spark.api.java.AbstractJavaRDDLike.collect(JavaRDDLike.scala:45) at com.chatSparkConnactionTest.JavaDemo.main(JavaDemo.java:37) Caused by: java.lang.ClassNotFoundException: org.apache.spark.sql.Dataset at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 58 more
我更新了pom.xml,但没有解决错误。有人可以帮我解决这个问题吗?
I made my pom.xml updated but that didn't resolve the error. Could anybody help me to resolve this problem?
谢谢!
更新1:
这里是我的构建路径截图:
链接到我的屏幕截图
推荐答案
您收到java.lang.NoClassDefFoundError:org / apache / spark / sql / Dataset错误,因为缺少spark-sql依赖项从您的pom.xml文件。
You are getting "java.lang.NoClassDefFoundError: org/apache/spark/sql/Dataset" error because "spark-sql" dependency is missing from your pom.xml file.
如果你想用Spark 2.0.0读取Cassandra表,那么你需要低于最小的依赖性。
If you want to read Cassandra table with Spark 2.0.0 then you need below minimum dependencies.
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.0.0</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.0.0</version>
</dependency>
<dependency>
<groupId>com.datastax.spark</groupId>
<artifactId>spark-cassandra-connector_2.11</artifactId>
<version>2.0.0-M3</version>
</dependency>
Spark 2.0.0提供SparkSession和Dataset API。下面是用于读取Cassandra表并打印记录的示例程序。
Spark 2.0.0 provides SparkSession and Dataset API. Below is the sample program for reading Cassandra table and printing the records.
public class SparkCassandraDatasetApplication {
public static void main(String[] args) {
SparkSession spark = SparkSession
.builder()
.appName("SparkCassandraDatasetApplication")
.config("spark.sql.warehouse.dir", "/file:C:/temp")
.config("spark.cassandra.connection.host", "127.0.0.1")
.config("spark.cassandra.connection.port", "9042")
.master("local[2]")
.getOrCreate();
//Read data
Dataset<Row> dataset = spark.read().format("org.apache.spark.sql.cassandra")
.options(new HashMap<String, String>() {
{
put("keyspace", "mykeyspace");
put("table", "mytable");
}
}).load();
//Print data
dataset.show();
spark.stop();
}
}
如果您仍想使用RDD,请使用以下示例程序。
If you still want to use RDD then use below sample program.
public class SparkCassandraRDDApplication {
public static void main(String[] args) {
SparkConf conf = new SparkConf()
.setAppName("SparkCassandraRDDApplication")
.setMaster("local[2]")
.set("spark.cassandra.connection.host", "127.0.0.1")
.set("spark.cassandra.connection.port", "9042");
JavaSparkContext sc = new JavaSparkContext(conf);
//Read
JavaRDD<UserData> resultsRDD = javaFunctions(sc).cassandraTable("mykeyspace", "mytable",CassandraJavaUtil.mapRowTo(UserData.class));
//Print
resultsRDD.foreach(data -> {
System.out.println(data.id);
System.out.println(data.username);
});
sc.stop();
}
}
上面程序中使用的Javabean(UserData)如下所示。
Javabean (UserData) used in above program is like below.
public class UserData implements Serializable{
String id;
String username;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
}
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