【轉】Java從hdfs上讀取文件中的某一行

【From】http://www.javashuo.com/article/p-dyjyirdz-dc.html

 

package test;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
 
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
 
public class ReadHDFS {
 
    public static String getStringByTXT(String txtFilePath, Configuration conf)
    {
 
        StringBuffer buffer = new StringBuffer();
        FSDataInputStream fsr = null;
        BufferedReader bufferedReader = null;
        String lineTxt = null;
        try
        {
            FileSystem fs = FileSystem.get(URI.create(txtFilePath),conf);
            fsr = fs.open(new Path(txtFilePath));
            bufferedReader = new BufferedReader(new InputStreamReader(fsr));        
            while ((lineTxt = bufferedReader.readLine()) != null)
            {
                if(lineTxt.split("\t")[0].trim().equals("00067")){
                    return lineTxt;
                }
                
            }
        } catch (Exception e)
        {
            e.printStackTrace();
        } finally
        {
            if (bufferedReader != null)
            {
                try
                {
                    bufferedReader.close();
                } catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }
 
        return lineTxt;
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Configuration conf = new Configuration();
        String txtFilePath = "hdfs://master:9000/OutPutBus/line/part-r-00000";
        String mbline = getStringByTXT(txtFilePath, conf);
        System.out.println(mbline);
    }
 
}
--------------------- 
做者：cao_yaqi 
來源：CSDN 
原文：https://blog.csdn.net/u010989078/article/details/51790166 
版權聲明：本文爲博主原創文章，轉載請附上博文連接！