Can someone give example of correct usage of mapPartitionsWithIndex in Java? I've found a lot of Scala examples, but there is lack of Java ones. Is my understanding correct that separate partitions will be handled by separate nodes when using this function.
I am getting the following error
method mapPartitionsWithIndex in class JavaRDD<T> cannot be applied to given types;
JavaRDD<String> rdd = sc.textFile(filename).mapPartitionsWithIndex
required: Function2<Integer,Iterator<String>,Iterator<R>>,boolean
found: <anonymous Function2<Integer,Iterator<String>,Iterator<JavaRDD<String>>>>
When doing
JavaRDD<String> rdd = sc.textFile(filename).mapPartitionsWithIndex(
new Function2<Integer, Iterator<String>, Iterator<JavaRDD<String>> >() {
@Override
public Iterator<JavaRDD<String>> call(Integer ind, String s) {
Here is the code I use to remove the first line of a csv file:
JavaRDD<String> rawInputRdd = sparkContext.textFile(dataFile);
Function2 removeHeader= new Function2<Integer, Iterator<String>, Iterator<String>>(){
@Override
public Iterator<String> call(Integer ind, Iterator<String> iterator) throws Exception {
if(ind==0 && iterator.hasNext()){
iterator.next();
return iterator;
}else
return iterator;
}
};
JavaRDD<String> inputRdd = rawInputRdd.mapPartitionsWithIndex(removeHeader, false);
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