我正在尝试将 Spark 2.3.1 与 Java 结合使用。

我遵循示例 in the documentation但在调用 .fit(trainingData) 时不断收到描述不佳的异常。

Exception in thread "main" java.lang.IllegalArgumentException
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.spark.util.ClosureCleaner$.getClassReader(ClosureCleaner.scala:46)
at org.apache.spark.util.FieldAccessFinder$$anon$3$$anonfun$visitMethodInsn$2.apply(ClosureCleaner.scala:449)
at org.apache.spark.util.FieldAccessFinder$$anon$3$$anonfun$visitMethodInsn$2.apply(ClosureCleaner.scala:432)
at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:733)
at scala.collection.mutable.HashMap$$anon$1$$anonfun$foreach$2.apply(HashMap.scala:103)
at scala.collection.mutable.HashMap$$anon$1$$anonfun$foreach$2.apply(HashMap.scala:103)
at scala.collection.mutable.HashTable$class.foreachEntry(HashTable.scala:230)
at scala.collection.mutable.HashMap.foreachEntry(HashMap.scala:40)
at scala.collection.mutable.HashMap$$anon$1.foreach(HashMap.scala:103)
at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:732)
at org.apache.spark.util.FieldAccessFinder$$anon$3.visitMethodInsn(ClosureCleaner.scala:432)
at org.apache.xbean.asm5.ClassReader.a(Unknown Source)
at org.apache.xbean.asm5.ClassReader.b(Unknown Source)
at org.apache.xbean.asm5.ClassReader.accept(Unknown Source)
at org.apache.xbean.asm5.ClassReader.accept(Unknown Source)
at org.apache.spark.util.ClosureCleaner$$anonfun$org$apache$spark$util$ClosureCleaner$$clean$14.apply(ClosureCleaner.scala:262)
at org.apache.spark.util.ClosureCleaner$$anonfun$org$apache$spark$util$ClosureCleaner$$clean$14.apply(ClosureCleaner.scala:261)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.apache.spark.util.ClosureCleaner$.org$apache$spark$util$ClosureCleaner$$clean(ClosureCleaner.scala:261)
at org.apache.spark.util.ClosureCleaner$.clean(ClosureCleaner.scala:159)
at org.apache.spark.SparkContext.clean(SparkContext.scala:2299)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2073)
at org.apache.spark.rdd.RDD$$anonfun$take$1.apply(RDD.scala:1358)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
at org.apache.spark.rdd.RDD.withScope(RDD.scala:363)
at org.apache.spark.rdd.RDD.take(RDD.scala:1331)
at org.apache.spark.ml.tree.impl.DecisionTreeMetadata$.buildMetadata(DecisionTreeMetadata.scala:112)
at org.apache.spark.ml.tree.impl.RandomForest$.run(RandomForest.scala:105)
at org.apache.spark.ml.classification.DecisionTreeClassifier.train(DecisionTreeClassifier.scala:116)
at org.apache.spark.ml.classification.DecisionTreeClassifier.train(DecisionTreeClassifier.scala:45)
at org.apache.spark.ml.Predictor.fit(Predictor.scala:118)
at com.example.spark.MyApp.main(MyApp.java:36)

我将这个虚拟数据集用于分类(data.csv):

f,label
1,1
1.5,1
0,0
2,2
2.5,2

我的代码:

SparkSession spark = SparkSession.builder()
            .master("local[1]")
            .appName("My App")
            .getOrCreate();

    Dataset<Row> data = spark.read().format("csv")
            .option("header", "true")
            .option("inferSchema", "true")
            .load("C:\\tmp\\data.csv");

    data.show();  // see output(1) below

    VectorAssembler assembler = new VectorAssembler()
            .setInputCols(Collections.singletonList("f").toArray(new String[0]))
            .setOutputCol("features");

    Dataset<Row> trainingData = assembler.transform(data)
            .select("features", "label");

    trainingData.show();  // see output(2) below

    DecisionTreeClassifier clf = new DecisionTreeClassifier();
    DecisionTreeClassificationModel model = clf.fit(trainingData);  // fails here (MyApp.java:36)
    Dataset<Row> predictions = model.transform(trainingData);

    predictions.show();  // never reached

输出(1):

+---+-----+
|  f|label|
+---+-----+
|1.0|    1|
|1.5|    1|
|0.0|    0|
|2.0|    2|
|2.5|    2|
+---+-----+

输出(2):

+--------+-----+
|features|label|
+--------+-----+
|   [1.0]|    1|
|   [1.5]|    1|
|   [0.0]|    0|
|   [2.0]|    2|
|   [2.5]|    2|
+--------+-----+

我的 build.gradle 文件如下所示:

plugins {
    id 'java'
    id 'application'
}

group 'com.example'
version '1.0-SNAPSHOT'

sourceCompatibility = 1.8
mainClassName = 'MyApp'

repositories {
    mavenCentral()
}

dependencies {
    compile group: 'org.apache.spark', name: 'spark-core_2.11', version: '2.3.1'
    compile group: 'org.apache.spark', name: 'spark-sql_2.11', version: '2.3.1'
    compile group: 'org.apache.spark', name: 'spark-mllib_2.11', version: '2.3.1'
}

我错过了什么？

最佳答案

您的机器上下载的是什么 Java 版本？ 您的问题可能与 Java 9 有关。

如果您下载 Java 8(例如 jdk-8u171)，异常将消失，predictions.show() 的输出 (3) 将如下所示:

+--------+-----+-------------+-------------+----------+
|features|label|rawPrediction|  probability|prediction|
+--------+-----+-------------+-------------+----------+
|   [1.0]|    1|[0.0,2.0,0.0]|[0.0,1.0,0.0]|       1.0|
|   [1.5]|    1|[0.0,2.0,0.0]|[0.0,1.0,0.0]|       1.0|
|   [0.0]|    0|[1.0,0.0,0.0]|[1.0,0.0,0.0]|       0.0|
|   [2.0]|    2|[0.0,0.0,2.0]|[0.0,0.0,1.0]|       2.0|
|   [2.5]|    2|[0.0,0.0,2.0]|[0.0,0.0,1.0]|       2.0|
+--------+-----+-------------+-------------+----------+

关于java - org.apache.xbean.asm5.ClassReader 中的 Spark Java IllegalArgumentException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/51352591/