public static SequenceFile.Writer createSequenceWriter(JobConf jc, FileSystem fs, Path file,
      Class<?> keyClass, Class<?> valClass, boolean isCompressed, Progressable progressable)
      throws IOException {
    CompressionCodec codec = null;
    CompressionType compressionType = CompressionType.NONE;
    Class<? extends CompressionCodec> codecClass = null;
    if (isCompressed) {
      compressionType = SequenceFileOutputFormat.getOutputCompressionType(jc);
      codecClass = FileOutputFormat.getOutputCompressorClass(jc, DefaultCodec.class);
      codec = ReflectionUtil.newInstance(codecClass, jc);
    }
    return SequenceFile.createWriter(fs, jc, file, keyClass, valClass, compressionType, codec,
      progressable);

  }
Create a sequencefile output stream based on job configuration Uses user supplied compression
flag (rather than obtaining it from the Job Configuration).

@param jc
         Job configuration
@param fs
         File System to create file in
@param file
         Path to be created
@param keyClass
         Java Class for key
@param valClass
         Java Class for value
@return output stream over the created sequencefile
ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java