Hadoop - java.lang.RuntimeException: java.lang.InstantiationException

Question

I'm trying to run a map reduction program on the client side (widow-7), this is the map reduction class:

Configuration conf =  new Configuration();

    conf.addResource(new Path("C:\\app\\hadoop-2.0.0-cdh4.3.0\\etc\\hadoop\\core-site.xml"));
    conf.addResource(new Path("C:\\app\\hadoop-2.0.0-cdh4.3.0\\etc\\hadoop\\hdfs-site.xml"));

    conf.set("fs.defaultFS", "hdfs://host:8020");
    conf.set("mapred.job.tracker", "host:8021");

    Job job = new Job(conf, "mapRed");
    job.setMapperClass(MapClass.class);
    //job.setInputFormatClass(org.apache.hadoop.mapreduce.lib.input.TextInputFormat.class);
    int numreducers = 1;

    job.setNumReduceTasks(numreducers);
    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(Text.class);

    Path inp = new Path("/data/test");
    FileInputFormat.addInputPath(job, inp);
    FileOutputFormat.setOutputPath(job, new Path("/data"));
    System.exit(job.waitForCompletion(true) ? 0 : 1);

This program throws an exception:

    13/12/14 08:27:52 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Exception in thread "main" java.lang.RuntimeException: java.lang.InstantiationException
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:128)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2307)
    at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:87)
    at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2342)
    at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2324)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:351)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:163)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:335)
    at org.apache.hadoop.fs.Path.getFileSystem(Path.java:194)
    at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.addInputPath(FileInputFormat.java:368)
    at org.gridedge.finalytics.MRTemplate.main(MRTemplate.java:55)
Caused by: java.lang.InstantiationException
    at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:126)
    ... 10 more

I found a simple question asked here by InstantationException in the hasoop map shortener program , and I changed FileInputFormat to TextInputFormat:

 TextInputFormat.addInputPath(job, inp);
 TextOutputFormat.setOutputPath(job, new Path("/data"));

The error remains the same, and its throw in the line FileInputFormat.addInputPath(job, inp);

Answer 1

The correct setting is to set TextInputFormat in the setInputFormat method. This line seems to be commented out in your code. Comment on this and then try using

FileInputFormat.addInputPaths.

, .

job.setInputFormatClass(TextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class);

, - - .