Reading a file in Java hdfs

问题

I ran into a problem running the program on a cluster and decided to read from hdfs file in functions map and reduce. How to read line by line hdfs file and burn to read rows in ArrayList?

回答1:

Just a code snippet for demonstration：

Path path = new Path(filePath);
FileSystem fs = path.getFileSystem(context.getConfiguration()); // context of mapper or reducer
FSDataInputStream fdsis = fs.open(path);
BufferedReader br = new BufferedReader(new InputStreamReader(fdsis));
String line = "";
ArrayList<String> lines = new ArrayList<String>();
while ((line = br.readLine()) != null) {
    lines.add(line);
}
br.close();

来源：https://stackoverflow.com/questions/13166123/reading-a-file-in-java-hdfs