Java – Custom MapReduce input format – constructor not found

I'm working for Hadoop 0.20 2 write a custom inputformat, and I can't get rid of nosuchmethodexception When I started:

public class ConnectionInputFormat extends FileInputFormat<Text,Connection> {

    @Override
    public RecordReader<Text,Connection> createRecordReader(InputSplit split,TaskAttemptContext context) throws IOException,InterruptedException {
        return new ConnectionRecordReader();
    }
}

This error occurred while running:

Exception in thread "main" java.lang.RuntimeException: java.lang.NoSuchMethodException: testingground.TestInputJob$ConnectionInputFormat.<init>()
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:115)
at org.apache.hadoop.mapred.JobClient.writeNewSplits(JobClient.java:882)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:779)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:432)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:447)
at testingground.TestInputJob.run(TestInputJob.java:141)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at testingground.TestInputJob.main(TestInputJob.java:156)
Caused by: java.lang.NoSuchMethodException: testingground.TestInputJob$ConnectionInputFormat.<init>()
at java.lang.Class.getConstructor0(Class.java:2706)
at java.lang.Class.getDeclaredConstructor(Class.java:1985)
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:109)
... 8 more
Java Result: 1

After the initialization error and online research, I think it may be because I don't have a zero parameter constructor, so I added one:

public class ConnectionInputFormat extends FileInputFormat<Text,Connection> {

    public ConnectionInputFormat() {
        System.out.println("NetflowInputFormat Constructor");
    }

    @Override
    public RecordReader<Text,InterruptedException {
        return new ConnectionRecordReader();
    }
}

This is useless, so I added a second constructor that accepts any number of objects:

public class ConnectionInputFormat extends FileInputFormat<Text,Connection> {

    public ConnectionInputFormat() {
        System.out.println("NetflowInputFormat Constructor");
    }

    public ConnectionInputFormat(Object... o) {
        System.out.println("NetflowInputFormat Constructor");
    }

    @Override
    public RecordReader<Text,InterruptedException {
        return new ConnectionRecordReader();
    }
}

It is not successful to still get the same error and cannot find a solution so far

Full current source: http://pastebin.com/2XyW5ZSS

Solution

Your connectioninputformat class should be static Non - static nested classes add an implicit "this" to each constructor Therefore, the no Arg constructor actually has invisible parameters unless the class is declared static