把本地文件夾下的所有文件上傳到hdfs上并合并成一個文件

來自： http://my.oschina.net/u/914897/blog/616682

需要自己寫代碼來實現：

/**
 * 
 */
package com.jason.hadoop.example;

import java.io.IOException;
import java.net.URI;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import  org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

/**
 * @author jason
 *
 */
public class PutMerge {

    public static void main(String[] args) throws IOException {
        Configuration conf = new Configuration();
         conf.addResource("classpath:/hadoop/core-site.xml");
          conf.addResource("classpath:/hadoop/hdfs-site.xml");
          conf.addResource("classpath:/hadoop/mapred-site.xml");
        FileSystem hdfs = FileSystem.get(URI.create(args[1]), conf);
//          FileSystem hdfs = FileSystem.get(conf);
        FileSystem local = FileSystem.getLocal(conf);
        Path inputDlir = new Path(args[0]);
        Path hdfsFile = new Path(args[2]);
        try {
            FileStatus[] inputFiles = local.listStatus(inputDlir);
            FSDataOutputStream out = hdfs.create(hdfsFile);
            for (int i=0; i<inputFiles.length; i++) {
                System.out.println(inputFiles[i].getPath().getName());
                FSDataInputStream in = local.open(inputFiles[i].getPath());
                byte[] buffer = new byte[256];
                int bytesRead = 0;
                while ((bytesRead = in.read(buffer)) > 0) {
                    out.write(buffer, 0 , bytesRead);
                }
                in.close();
            }
            out.close();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
    }
}

把工程打成jar包后，執行以下命令即可：

hadoop jar hadoopExample-1.0-SNAPSHOT.jar com.jason.hadoop.example.PutMerge /home/jason/hadoop-1.0.1/put_merge hdfs://localhost:9000 /example/put_merge/in/merge_222.txt