Can we change the default key-value output seperator in Hadoop MapReduce

Yes, We can change it using "mapred.textoutputformat.separator" property in Driver class, if we are using TextOutputFormat as Output Format.Default seperator is "\t".

Change to ","

Configuration conf = getConf();
conf.set("mapred.textoutputformat.separator", ","); 

Change to ";"

Configuration conf = getConf();
conf.set("mapred.textoutputformat.separator", ";"); 

Change to ":"

Configuration conf = getConf();
conf.set("mapred.textoutputformat.separator", ":"); 

Happy Hadooping ...