By default the key class is BytesWritable.class, In case you are using some different class you can provide it as an extra argument, something like -outKey LongWritable.class along with your existing arguments
On Mon, 2 May 2022 at 06:02, Pratyush Das <[email protected]> wrote: > With the invocation - hadoop jar > hadoop-3.3.1/share/hadoop/mapreduce/hadoop-mapreduce-examples-3.3.1.jar > join -inFormat org.apache.hadoop.mapreduce.lib.input.TextInputFormat > /examples-input/ /examples-output/, I get the error - java.lang.Exception: > java.io.IOException: wrong key class: org.apache.hadoop.io.LongWritable is > not class org.apache.hadoop.io.BytesWritable > > So, it looks like the previous issue was solved, but something else might > be happening? Is it necessary to manually specify a key class? > > On Sun, 1 May 2022 at 19:47, Ayush Saxena <[email protected]> wrote: > >> Hi Pratyush, >> Can you try the class along with the package: >> >> *org.apache.hadoop.mapreduce.lib.input.TextInputFormat* >> >> It should work. All subclasses of InputFormat.java should work. >> >> -Ayush >> >> >> On 02-May-2022, at 4:53 AM, Pratyush Das <[email protected]> wrote: >> >> >> Hi, >> >> I tried executing the Join.java example in the Hadoop Mapreduce Examples >> jar using the following invocation - hadoop jar >> hadoop-3.3.1/share/hadoop/mapreduce/hadoop-mapreduce-examples-3.3.1.jar >> join -inFormat TextInputFormat /examples-input/ /examples-output/ >> >> I keep getting an error - java.lang.ClassNotFoundException: >> TextInputFormat >> >> This is the given invocation of the join example - >> join [-r <reduces>] [-inFormat <input format class>] [-outFormat <output >> format class>] [-outKey <output key class>] [-outValue <output value >> class>] [-joinOp <inner|outer|override>] [input]* <input> <output> >> >> What are the possible values of inFormat and outFormat? I have also tried >> "TextInputFormat.class" which did not work. >> >> Thanks, >> >> -- >> Pratyush Das >> >> > > -- > Pratyush Das >
