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copied!<p>The classes required for this are <a href="http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/fs/FileSystem.html" rel="noreferrer">FileSystem</a>, <a href="http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/fs/FSDataInputStream.html" rel="noreferrer">FSDataInputStream</a> and <a href="http://hadoop.apache.org/docs/r1.0.4/api/org/apache/hadoop/fs/Path.html" rel="noreferrer">Path</a>. Client should be something like this :</p> <pre><code>public static void main(String[] args) throws IOException { // TODO Auto-generated method stub Configuration conf = new Configuration(); conf.addResource(new Path("/hadoop/projects/hadoop-1.0.4/conf/core-site.xml")); conf.addResource(new Path("/hadoop/projects/hadoop-1.0.4/conf/hdfs-site.xml")); FileSystem fs = FileSystem.get(conf); FSDataInputStream inputStream = fs.open(new Path("/path/to/input/file")); System.out.println(inputStream.readChar()); } </code></pre> <p>FSDataInputStream has several <code>read</code> methods. Choose the one which suits your needs.</p> <p>If it is MR, it's even easier :</p> <pre><code> public static class YourMapper extends Mapper<LongWritable, Text, Your_Wish, Your_Wish> { public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { //Framework does the reading for you... String line = value.toString(); //line contains one line of your csv file. //do your processing here .................... .................... context.write(Your_Wish, Your_Wish); } } } </code></pre>

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