使用Hadoop自己的类操作HDFS

 

 

package hdfs;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

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;
import org.apache.hadoop.io.IOUtils;

public class App2 {
    static final String PATH = "hdfs://chaoren:9000/";
    static final String DIR = "/d1";
    static final String FILE = "/d1/hello";
    public static void main(String[] args) throws Exception {
        FileSystem fileSystem = getFileSystem();
        //创建文件夹     hadoop fs -mkdir   /f1
        mkdir(fileSystem);
        //上传文件  -put  src  des
        putData(fileSystem);
        //下载文件   hadoop fs -get src des
        //getData(fileSystem);
        //浏览文件夹
        list(fileSystem);
        //删除文件夹
        //remove(fileSystem);
    }
    private static void list(FileSystem fileSystem) throws IOException {
        final FileStatus[] listStatus = fileSystem.listStatus(new Path("/"));
        for (FileStatus fileStatus : listStatus) {
            String isDir = fileStatus.isDir()?"文件夹":"文件";
            final String permission = fileStatus.getPermission().toString();
            final short replication = fileStatus.getReplication();
            final long len = fileStatus.getLen();
            final String path = fileStatus.getPath().toString();
            System.out.println(isDir+"\t"+permission+"\t"+replication+"\t"+len+"\t"+path);
        }
    }
    private static void getData(FileSystem fileSystem) throws IOException {
        final FSDataInputStream in = fileSystem.open(new Path(FILE));
        IOUtils.copyBytes(in, System.out, 1024, true);
    }
    private static void putData(FileSystem fileSystem) throws IOException,
            FileNotFoundException {
        final FSDataOutputStream out = fileSystem.create(new Path(FILE));
        final FileInputStream in = new FileInputStream("H:/kuaipan/hadoop/classes/yy131009/day2/readme.txt");
        IOUtils.copyBytes(in, out, 1024, true);
    }
    private static void remove(FileSystem fileSystem) throws IOException {
        fileSystem.delete(new Path(DIR), true);
    }
    private static void mkdir(FileSystem fileSystem) throws IOException {
        fileSystem.mkdirs(new Path(DIR));
    }
    private static FileSystem getFileSystem() throws IOException, URISyntaxException {
        return FileSystem.get(new URI(PATH), new Configuration());
    }
}