当我申请ParDo.of(new ParDoFn())
到PCollection
名为textInput
时,程序会抛出此异常。但是当我删除.apply(ParDo.of(new ParDoFn()))
时,程序正常。AssertionError:声明失败:copyAndReset必须返回一个零值副本
// SparkRunner
private static void testHadoop(Pipeline pipeline){
Class<? extends FileInputFormat<LongWritable, Text>> inputFormatClass =
(Class<? extends FileInputFormat<LongWritable, Text>>)
(Class<?>) TextInputFormat.class;
@SuppressWarnings("unchecked") //hdfs://localhost:9000
HadoopIO.Read.Bound<LongWritable, Text> readPTransfom_1 = HadoopIO.Read.from("hdfs://localhost:9000/tmp/kinglear.txt",
inputFormatClass,
LongWritable.class,
Text.class);
PCollection<KV<LongWritable, Text>> textInput = pipeline.apply(readPTransfom_1)
.setCoder(KvCoder.of(WritableCoder.of(LongWritable.class), WritableCoder.of(Text.class)));
//OutputFormat
@SuppressWarnings("unchecked")
Class<? extends FileOutputFormat<LongWritable, Text>> outputFormatClass =
(Class<? extends FileOutputFormat<LongWritable, Text>>)
(Class<?>) TemplatedTextOutputFormat.class;
@SuppressWarnings("unchecked")
HadoopIO.Write.Bound<LongWritable, Text> writePTransform = HadoopIO.Write.to("hdfs://localhost:9000/tmp/output", outputFormatClass, LongWritable.class, Text.class);
textInput.apply(ParDo.of(new ParDoFn())).apply(writePTransform.withoutSharding());
pipeline.run().waitUntilFinish();
}
你能否在你的问题中包含完整的异常堆栈跟踪?这有助于缩小问题的范围。另外,您可能想尝试遵循Apache Beam示例中的样式 - 您构建的变换仅使用一次;你可能想要内联他们,你的代码将更具可读性。 –