java 实现hadoop的hdfs文件的上传下载删除创建

java 实现 hdfs文件的上传下载删除创建

package org.apache.hadoop.examples;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
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.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;

/**
* hdfs在java 的方法（创建文件夹 上传文件 下载文件 删除文件）
* @author hadoop
*
*/
public class HdfsUtil {

public static final String HDFS_PATH = "hdfs://localhost:9000/user/hadoop/hello";
public static final String DIR_PATH = "hdfs://localhost:9000/user/hadoop/hello";
public static final String FILE_PATH = "hdfs://localhost:9000/user/hadoop/hello";

public static void main(String[] args) throws Exception {
final FileSystem fileSystem = FileSystem.get(new URI(HDFS_PATH),
new Configuration());
// 创建文件夹
//       makeDirectory(fileSystem);
// 上传文件
//       uploadData(fileSystem);
// 下载文件
//       downloadData(fileSystem);
// 删除文件
deleteFile(fileSystem);

}

private static void deleteFile(final FileSystem fileSystem)
throws IOException {
// 删除文件-true/false（文件夹-true）
fileSystem.delete(new Path(FILE_PATH), true);
}

private static void downloadData(final FileSystem fileSystem)
throws IOException {
final FSDataInputStream in = fileSystem.open(new Path(FILE_PATH));
IOUtils.copyBytes(in, System.out, 1024, true);
}

private static void makeDirectory(final FileSystem fileSystem)
throws IOException {
// 创建文件夹
fileSystem.mkdirs(new Path(DIR_PATH));
}

private static void uploadData(final FileSystem fileSystem)
throws IOException, FileNotFoundException {
// 上传文件
final FSDataOutputStream out = fileSystem.create(new Path(FILE_PATH)); //上传后的文件命令名
FileInputStream in = new FileInputStream("./hello.txt"); //上传的文件
IOUtils.copyBytes(in, out, 1024, true);
}

}