如何将.txt文件转换为Hadoop的序列文件格式

因此，最简单的答案就是只有一个具有SequenceFile输出的“身份”工作。

在Java中看起来像这样：

    public static void main(String[] args) throws IOException,        InterruptedException, ClassNotFoundException {    Configuration conf = new Configuration();    Job job = new Job(conf);    job.setJobName("Convert Text");    job.setJarByClass(Mapper.class);    job.setMapperClass(Mapper.class);    job.setReducerClass(Reducer.class);    // increase if you need sorting or a special number of files    job.setNumReduceTasks(0);    job.setOutputKeyClass(LongWritable.class);    job.setOutputValueClass(Text.class);    job.setOutputFormatClass(SequenceFileOutputFormat.class);    job.setInputFormatClass(TextInputFormat.class);    TextInputFormat.addInputPath(job, new Path("/lol"));    SequenceFileOutputFormat.setOutputPath(job, new Path("/lolz"));    // submit and wait for completion    job.waitForCompletion(true);   }