hadoop读取数据

package hadoopshiyan;


import org.apache.hadoop.fs.*;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class hadoopduqu extends FSDataInputStream {

    private static hadoopduqu myFSDataInputStream;
    private static InputStream inputStream;

    private hadoopduqu(InputStream in) {
        super(in);
        inputStream = in;
    }

    public static hadoopduqu getInstance(InputStream inputStream){
        if (null == myFSDataInputStream){
            synchronized (hadoopduqu.class){
                if (null == myFSDataInputStream){
                    myFSDataInputStream = new hadoopduqu(inputStream);
                }
            }
        }
        return myFSDataInputStream;
    }

    public static String readline(FileSystem fileStatus){
        try {
//            FSDataInputStream inputStream = fileStatus.open(remotePath);
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            String line = null;
            if ((line = bufferedReader.readLine()) != null){
                bufferedReader.close();
                inputStream.close();
                return line;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

package hadoopshiyan;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FsUrlStreamHandlerFactory;
import org.apache.hadoop.fs.Path;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;

public class shuchu {

    private Path remotePath;
    private FileSystem fileSystem;

    public shuchu(FileSystem fileSystem, Path remotePath){
        this.fileSystem = fileSystem;
        this.remotePath = remotePath;
    }

    public void show(){
        try {
            URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory());
            InputStream inputStream = new URL("hdfs","localhost",8020,remotePath.toString()).openStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            String line = null;
            while ((line = bufferedReader.readLine()) != null){
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}