Cloudera CDH/CDP 및 Hadoop EcoSystem, Semantic IoT등의 개발/운영 기술을 정리합니다. gooper@gooper.com로 문의 주세요.
Hadoop 2.7.x에서 사용할 수 있는 파일/디렉토리 관련 utils
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 | import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;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;public class HDFSUtils { /** * create a existing file from local filesystem to hdfs * @param source * @param dest * @param conf * @throws IOException */ public void addFile(String source, String dest, Configuration conf) throws IOException { FileSystem fileSystem = FileSystem.get(conf); // Get the filename out of the file path String filename = source.substring(source.lastIndexOf('/') + 1,source.length()); // Create the destination path including the filename. if (dest.charAt(dest.length() - 1) != '/') { dest = dest + "/" + filename; } else { dest = dest + filename; } // System.out.println("Adding file to " + destination); // Check if the file already exists Path path = new Path(dest); if (fileSystem.exists(path)) { System.out.println("File " + dest + " already exists"); return; } // Create a new file and write data to it. FSDataOutputStream out = fileSystem.create(path); InputStream in = new BufferedInputStream(new FileInputStream(new File( source))); byte[] b = new byte[1024]; int numBytes = 0; while ((numBytes = in.read(b)) > 0) { out.write(b, 0, numBytes); } // Close all the file descriptors in.close(); out.close(); fileSystem.close(); } /** * read a file from hdfs * @param file * @param conf * @throws IOException */ public void readFile(String file, Configuration conf) throws IOException { FileSystem fileSystem = FileSystem.get(conf); Path path = new Path(file); if (!fileSystem.exists(path)) { System.out.println("File " + file + " does not exists"); return; } FSDataInputStream in = fileSystem.open(path); String filename = file.substring(file.lastIndexOf('/') + 1, file.length()); OutputStream out = new BufferedOutputStream(new FileOutputStream( new File(filename))); byte[] b = new byte[1024]; int numBytes = 0; while ((numBytes = in.read(b)) > 0) { out.write(b, 0, numBytes); } in.close(); out.close(); fileSystem.close(); } /** * delete a directory in hdfs * @param file * @throws IOException */ public void deleteFile(String file, Configuration conf) throws IOException { FileSystem fileSystem = FileSystem.get(conf); Path path = new Path(file); if (!fileSystem.exists(path)) { System.out.println("File " + file + " does not exists"); return; } fileSystem.delete(new Path(file), true); fileSystem.close(); } /** * create directory in hdfs * @param dir * @throws IOException */ public void mkdir(String dir, Configuration conf) throws IOException { FileSystem fileSystem = FileSystem.get(conf); Path path = new Path(dir); if (fileSystem.exists(path)) { System.out.println("Dir " + dir + " already exists"); return; } else { fileSystem.mkdirs(path); fileSystem.close(); } } /** * delete directory in hdfs * @param dir * @throws IOException */ public void rmdir(String dir, Configuration conf) throws IOException { FileSystem fileSystem = FileSystem.get(conf); Path path = new Path(dir); if (fileSystem.exists(path)) { fileSystem.delete(path, true); fileSystem.close(); } else { System.out.println("Dir " + dir + " not exists"); } } /* public static void main(String[] args) throws IOException { if (args.length < 1) { System.out.println("Usage: hdfsclient add/read/delete/mkdir" + " [<local_path> <hdfs_path>]"); System.exit(1); } FileSystemOperations client = new FileSystemOperations(); String hdfsPath = "hdfs://" + args[0] + ":" + args[1]; Configuration conf = new Configuration(); // Providing conf files // conf.addResource(new Path(HDFSAPIDemo.class.getResource("/conf/core-site.xml").getFile())); // conf.addResource(new Path(HDFSAPIDemo.class.getResource("/conf/hdfs-site.xml").getFile())); // (or) using relative paths // conf.addResource(new Path( // "/u/hadoop-1.0.2/conf/core-site.xml")); // conf.addResource(new Path( // "/u/hadoop-1.0.2/conf/hdfs-site.xml")); //(or) // alternatively provide namenode host and port info conf.set("fs.default.name", hdfsPath); if (args[0].equals("add")) { if (args.length < 3) { System.out.println("Usage: hdfsclient add <local_path> " + "<hdfs_path>"); System.exit(1); } client.addFile(args[1], args[2], conf); } else if (args[0].equals("read")) { if (args.length < 2) { System.out.println("Usage: hdfsclient read <hdfs_path>"); System.exit(1); } client.readFile(args[1], conf); } else if (args[0].equals("delete")) { if (args.length < 2) { System.out.println("Usage: hdfsclient delete <hdfs_path>"); System.exit(1); } client.deleteFile(args[1], conf); } else if (args[0].equals("mkdir")) { if (args.length < 2) { System.out.println("Usage: hdfsclient mkdir <hdfs_path>"); System.exit(1); } client.mkdir(args[1], conf); } else { System.out.println("Usage: hdfsclient add/read/delete/mkdir" + " [<local_path> <hdfs_path>]"); System.exit(1); } System.out.println("Done!"); } */} |
