TestJoinDatamerge.java 文件源码

private static int countProduct(IntWritable key, Path[] src, 
    Configuration conf) throws IOException {
  int product = 1;
  for (Path p : src) {
    int count = 0;
    SequenceFile.Reader r = new SequenceFile.Reader(
      cluster.getFileSystem(), p, conf);
    IntWritable k = new IntWritable();
    IntWritable v = new IntWritable();
    while (r.next(k, v)) {
      if (k.equals(key)) {
        count++;
      }
    }
    r.close();
    if (count != 0) {
      product *= count;
    }
  }
  return product;
}