HDFS java api 文件基本操作

package hdfs;import java.io.BufferedReader;import java.io.ByteArrayInputStream;import java.io.File;import java.io.IOException;import java.io.InputStreamReader;import java.net.URI;import java.util.Scanner;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 HdfsOperation {    public static final String BASE_URL = "hdfs://hadoop-master.wei.com:9000";    public static Configuration conf;    public static FileSystem fs;    //静态代码块创建fs文件系统对象    static {        conf = new Configuration();        try {            fs = FileSystem.get(URI.create(BASE_URL), conf);        } catch (IOException e) {            System.out.println("initialize filesystem error");            e.printStackTrace();        }    }    /*** 查看文件内容 ***/    public static void cat(String filePath) {        Path path = new Path(filePath);        FSDataInputStream inputStream = null;        try {            inputStream = fs.open(path);            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));            IOUtils.copyBytes(inputStream, System.out, 4096, false);        } catch (IOException e) {            e.printStackTrace();        } finally {            IOUtils.closeStream(inputStream);        }    }    /*** 上传文件到hdfs ***/    public static boolean put(boolean delSrcFile, boolean overwrite, String srcStr, String dstStr) throws IOException {        Path srcPath = new Path(srcStr);        Path dstPath = new Path(dstStr);        // 判断源文件是否存在        if (!(new File(srcStr)).exists()) {            System.out.println("上传的源文件不存在！");            return false;        }        // 判断上传目录是否存在        if (!fs.exists(dstPath)) {            System.out.println("上传路径不存在！");            return false;        }        fs.copyFromLocalFile(delSrcFile, overwrite, srcPath, dstPath);        System.out.println("上传到 :" + conf.get("fs.defaultFS.name") + dstStr);        // 列出该目录下的文件        System.out.println("-------list-----------");        FileStatus[] listStatus = fs.listStatus(dstPath);        for (FileStatus file : listStatus) {            System.out.println(file.getPath());        }        return true;    }    /*** 从hdfs下载文件 ***/    public static boolean get(boolean delSrc, String srcStr, String dstStr, boolean useRawLocalFileSystem)            throws IOException {        Path srcPath = new Path(srcStr);        Path dstPath = new Path(dstStr);        // 判断源文件是否存在        if (!fs.exists(srcPath)) {            System.out.println("源文件不存在");            return false;        }        // 判断目标路径是否存在,不存则创建        else if (!new File(dstStr).exists()) {            new File(dstStr).mkdirs();            System.out.println();        } else {            String fileName = srcPath.getName();            // 判断同名文件是否存在            if (new File(dstStr + "\\" + fileName).exists()) {                System.out.println("本地文件已存在！");                return false;            } else {                // 下载文件                fs.copyToLocalFile(delSrc, srcPath, dstPath, useRawLocalFileSystem);                System.out.println("download successful! At:" + dstStr);                return true;            }        }        return true;    }    /*** 删除文件 ***/    public static boolean rmFile(String filePath) throws IOException {        Path path = new Path(filePath);        boolean deleteOnExit = fs.deleteOnExit(path);        if (deleteOnExit) {            System.out.println("删除成功");            return deleteOnExit;        } else {            System.out.println("删除失败,文件不存在");            return deleteOnExit;        }    }    /*** 文件重命名 ***/    public static boolean renameFile(String oldName, String newName) throws IOException {        Path srcPath = new Path(oldName);        Path newPath = new Path(newName);        boolean isSuccess = fs.rename(srcPath, newPath);        if (isSuccess) {            System.out.println("重命名: " + oldName + " 为  " + newName);        } else {            System.out.println("重命名失败！");        }        return isSuccess;    }    /*** 创建文件,并且写入内容 ***/    public static boolean touch(String filePath, String content) throws IOException {        Path path = new Path(filePath);        byte[] contens = content.getBytes();        boolean overwrite;        if (fs.exists(path)) {            // 文件已经存在            while (true) {                System.out.println("文件已经存在,是否覆盖(y/n)?");                Scanner sc = new Scanner(System.in);                String input = sc.next();                if ("y".equals(input.trim()) || "Y".equals(input.trim())) {                    FSDataOutputStream out = fs.create(path, true);                    out.write(contens);                    out.close();                    System.out.println("文件创建成功！");                    return true;                } else if ("n".equals(input) || "N".equals(input)) {                    System.out.println("文件写入失败，文件已存在");                    return false;                } else {                    continue;                }            }        } else {            // 文件不存在            FSDataOutputStream out = fs.create(path);            out.write(contens);            out.close();            System.out.println("文件创建成功！");            return true;        }    }    /*** 创建文件夹 ***/    public static boolean mkdir(String dirPath) throws IOException {        Path path = new Path(dirPath);        boolean exists = fs.exists(path);        if (exists) {            System.out.println("目录已存在");            return false;        } else {            if (fs.mkdirs(path)) {                System.out.println("目录创建成功: " + dirPath);                return true;            }            return false;        }    }    /** 列出路径下的目录 **/    public static void ls(String path) throws IOException {        Path p = new Path(path);        if (!fs.exists(p)) {            System.out.println("路径：" + path + " 不存在！");        } else {            FileStatus[] listStatus = fs.listStatus(p);            System.out.println("under path:" + path);            for (FileStatus f : listStatus) {                System.out.println(f.getPath());            }        }    }    /** 添加内容到文件 **/    public static void append(String content, String filePath) throws IOException {        Path path = new Path(filePath);        // 将字符串转为输入流        ByteArrayInputStream in = new ByteArrayInputStream(content.getBytes());        // 获得添加 输出流        FSDataOutputStream out = fs.append(path, 4096);        IOUtils.copyBytes(in, out, 4096, true);    }}