/**
* Checks for the existence of an existing ARFF header file in HDFS or the local file system. If
* local, it is copied into HDFS.
*
* @throws DistributedWekaException if the file does not exist or there is a problem transfering
* it into HDFS
*/
protected void handleExistingHeaderFile() throws DistributedWekaException {
String existingPath = getPathToExistingHeader();
try {
existingPath = environmentSubstitute(existingPath);
} catch (Exception ex) {
}
// check local file system first
File f = new File(existingPath);
boolean success = false;
if (f.exists()) {
// copy this file into HDFS
String hdfsDest = HDFSUtils.WEKA_TEMP_DISTRIBUTED_CACHE_FILES + f.getName();
try {
HDFSUtils.copyToHDFS(existingPath, hdfsDest, m_mrConfig.getHDFSConfig(), m_env, true);
m_hdfsPathToAggregatedHeader = hdfsDest;
Configuration conf = new Configuration();
m_mrConfig.getHDFSConfig().configureForHadoop(conf, m_env);
getFinalHeaderFromHDFS(conf, hdfsDest);
success = true;
} catch (IOException e) {
throw new DistributedWekaException(e);
}
} else {
try {
Path p = new Path(existingPath);
Configuration conf = new Configuration();
m_mrConfig.getHDFSConfig().configureForHadoop(conf, m_env);
FileSystem fs = FileSystem.get(conf);
if (fs.exists(p)) {
m_hdfsPathToAggregatedHeader = existingPath;
getFinalHeaderFromHDFS(conf, existingPath);
success = true;
}
} catch (IOException ex) {
throw new DistributedWekaException(ex);
}
}
if (!success) {
throw new DistributedWekaException(
"Was unable to find '"
+ existingPath
+ "' on either "
+ "the local file system or in HDFS");
}
}
