java equivalent for scala classOf[]

Question

Can any one help me with the Java equivalent of this?

wordCountRDD.saveAsNewAPIHadoopFile(outputFile,classOf[Text],classOf[IntWritable],classOf[TextOutputFormat[Text,IntWritable]])

I tried below : but it give me error at TextOutputFormat<>(Text,IntWritable) ..

wordCountRDD.saveAsNewAPIHadoopFile(
                        output,
                        Text.class,
                        IntWritable.class,
                        TextOutputFormat<>(Text,IntWritable)
                        context.hadoopConfiguration());

Can you explain what it does? I know Java but I don't know Scala. — nishantc1527, Aug 14 '19 at 17:39
What is `TextOutputFormat<>(Text,IntWritable)` supposed to do? — Benjamin Urquhart, Aug 14 '19 at 17:40
sure, TextOutputFormat is to write the output to key and value pairs, where key is Text and value is IntWritable — Neethu Lalitha, Aug 14 '19 at 17:41

GhostCat · Accepted Answer · 2019-08-14T17:47:24.993

2

Here:

TextOutputFormat<>(Text,IntWritable)

You have to pass the class instead:

TextOutputFormat.class

But note: the java type system doesn't allow you to express something like. TextOutputFormat<Text,IntWritable>.class! See here for why that is.

From that point of view, TextOutputFormat.class seems to be your only option.

edited Aug 14 '19 at 17:47

answered Aug 14 '19 at 17:43

GhostCat

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The precise term for this behavior of generics is [type erasure](https://stackoverflow.com/a/339708/5699679) – Avi Aug 14 '19 at 17:47

java equivalent for scala classOf[]

1 Answers1