如何在Map-Reduce中从多个目录读取多个文件

Question

我想从Map-Reduce程序的多个目录中读取多个文件。 我试图在主方法中给出文件名：

FileInputFormat.setInputPaths(conf,new Path("hdfs://localhost:54310/user/test/"));
FileInputFormat.setInputPaths(conf,new Path("hdfs://localhost:54310/Test/test1/"));

但是它仅从一个文件读取。

读取多个文件该怎么办？

请提出解决方案。

谢谢。

Answer 1

FileInputFormat#setInputPaths将在覆盖之前设置的输入路径后设置输入路径。 使用FileInputFormat#addInputPath或FileInputFormat#addInputPaths添加到现有路径。

Answer 2

Follow the below steps for passsing multiple input files from different direcories.Just driver code changes.Follow the below driver code.
CODE:
public int run(String[] args) throws Exception {
        Configuration conf=new Configuration();
        Job job=Job.getInstance(conf, "MultipleDirectoryAsInput");

        job.setMapperClass(Map1Class.class);
        job.setMapperClass(Map2Class.class);
        job.setReducerClass(ReducerClass.class);        
         job.setJarByClass(DriverClass.class);      
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);      
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(NullWritable.class);        
        //FileInputFormat.setInputPaths(job, new Path(args[0]));        
        MultipleInputs.addInputPath(job, new Path(args[0]),TextInputFormat.class,Map1Class.class);
        MultipleInputs.addInputPath(job, new Path(args[1]), TextInputFormat.class, Map2Class.class);            
        FileOutputFormat.setOutputPath(job, new Path(args[2])); 
        return job.waitForCompletion(true)?0:1;     
    }