FileUtils.java revision 6d25a990afffd5eb385aba3043d5dfad36f1539a
19066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/* 29066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copyright (C) 2006 The Android Open Source Project 39066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 49066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 59066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * you may not use this file except in compliance with the License. 69066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * You may obtain a copy of the License at 79066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 89066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 99066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * See the License for the specific language governing permissions and 149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * limitations under the License. 159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpackage android.os; 189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.ByteArrayOutputStream; 209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.File; 219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.FileInputStream; 226d25a990afffd5eb385aba3043d5dfad36f1539aWink Savilleimport java.io.FileNotFoundException; 239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.FileOutputStream; 249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.IOException; 259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.io.InputStream; 269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport java.util.regex.Pattern; 276d25a990afffd5eb385aba3043d5dfad36f1539aWink Savilleimport java.util.zip.CRC32; 286d25a990afffd5eb385aba3043d5dfad36f1539aWink Savilleimport java.util.zip.CheckedInputStream; 299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/** 329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Tools for managing files. Not for public consumption. 339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @hide 349066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 356d25a990afffd5eb385aba3043d5dfad36f1539aWink Savillepublic class FileUtils { 369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IRWXU = 00700; 379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IRUSR = 00400; 389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IWUSR = 00200; 399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IXUSR = 00100; 409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 419066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IRWXG = 00070; 429066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IRGRP = 00040; 439066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IWGRP = 00020; 449066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IXGRP = 00010; 459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IRWXO = 00007; 479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IROTH = 00004; 489066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IWOTH = 00002; 499066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final int S_IXOTH = 00001; 509066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 519066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 529066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 539066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * File status information. This class maps directly to the POSIX stat structure. 549066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @hide 559066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 569066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static final class FileStatus { 579066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int dev; 589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int ino; 599066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int mode; 609066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int nlink; 619066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int uid; 629066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int gid; 639066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int rdev; 649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public long size; 659066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public int blksize; 669066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public long blocks; 679066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public long atime; 689066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public long mtime; 699066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public long ctime; 709066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 719066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 729066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 739066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Get the status for the given path. This is equivalent to the POSIX stat(2) system call. 749066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param path The path of the file to be stat'd. 759066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param status Optional argument to fill in. It will only fill in the status if the file 769066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * exists. 779066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return true if the file exists and false if it does not exist. If you do not have 789066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * permission to stat the file, then this method will return false. 799066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 804e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick public static boolean getFileStatus(String path, FileStatus status) { 814e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick StrictMode.noteDiskRead(); 824e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick return getFileStatusNative(path, status); 834e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick } 844e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick 854e920f70f38d52d3a74c6a3133388a2e2cb6c175Brad Fitzpatrick private static native boolean getFileStatusNative(String path, FileStatus status); 869066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 879066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** Regular expression for safe filenames: no spaces or metacharacters */ 889066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project private static final Pattern SAFE_FILENAME_PATTERN = Pattern.compile("[\\w%+,./=_-]+"); 899066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 909066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native int setPermissions(String file, int mode, int uid, int gid); 919066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 929066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native int getPermissions(String file, int[] outPermissions); 939066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 9490960e87ecae696f73ae18e46c2f003fc3f592ccMike Lockwood public static native int setUMask(int mask); 9590960e87ecae696f73ae18e46c2f003fc3f592ccMike Lockwood 969066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** returns the FAT file system volume ID for the volume mounted 979066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * at the given mount point, or -1 for failure 986d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * @param mountPoint point for FAT volume 999066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return volume ID or -1 1009066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1019066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native int getFatVolumeId(String mountPoint); 1028bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn 1038bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn /** 1048bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn * Perform an fsync on the given FileOutputStream. The stream at this 1058bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn * point must be flushed but not yet closed. 1068bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn */ 1078bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn public static boolean sync(FileOutputStream stream) { 1088bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn try { 1098bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn if (stream != null) { 1108bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn stream.getFD().sync(); 1118bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } 1128bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn return true; 1138bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } catch (IOException e) { 1148bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } 1158bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn return false; 1168bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } 1178bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn 1189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // copy a file from srcFile to destFile, return true if succeed, return 1199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // false if fail 1209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static boolean copyFile(File srcFile, File destFile) { 1219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project boolean result = false; 1229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 1239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project InputStream in = new FileInputStream(srcFile); 1249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 1259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project result = copyToFile(in, destFile); 1269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } finally { 1279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project in.close(); 1289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } catch (IOException e) { 1309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project result = false; 1319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return result; 1339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1349066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1359066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 1369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copy data from a source stream to destFile. 1379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Return true if succeed, return false if failed. 1389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static boolean copyToFile(InputStream inputStream, File destFile) { 1409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 1411afd1c90ebe789b8d3a137004127a50d2db7e3b5Dianne Hackborn if (destFile.exists()) { 1421afd1c90ebe789b8d3a137004127a50d2db7e3b5Dianne Hackborn destFile.delete(); 1431afd1c90ebe789b8d3a137004127a50d2db7e3b5Dianne Hackborn } 1448bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn FileOutputStream out = new FileOutputStream(destFile); 1459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 1469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project byte[] buffer = new byte[4096]; 1479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int bytesRead; 1489066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project while ((bytesRead = inputStream.read(buffer)) >= 0) { 1499066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project out.write(buffer, 0, bytesRead); 1509066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1519066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } finally { 1528bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn out.flush(); 1538bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn try { 1548bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn out.getFD().sync(); 1558bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } catch (IOException e) { 1568bdf5935c0db4a66ab33a10b43398d2523cfa15dDianne Hackborn } 1579066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project out.close(); 1589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1599066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return true; 1609066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } catch (IOException e) { 1619066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return false; 1629066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1639066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1659066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 1669066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Check if a filename is "safe" (no metacharacters or spaces). 1679066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param file The file to check 1689066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1699066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static boolean isFilenameSafe(File file) { 1709066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // Note, we check whether it matches what's known to be safe, 1719066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // rather than what's known to be unsafe. Non-ASCII, control 1729066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project // characters, etc. are all unsafe by default. 1739066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return SAFE_FILENAME_PATTERN.matcher(file.getPath()).matches(); 1749066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1759066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1769066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 1779066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Read a text file into a String, optionally limiting the length. 1789066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param file to read (will not seek, so things like /proc files are OK) 1799066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param max length (positive for head, negative of tail, 0 for no limit) 1809066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param ellipsis to add of the file was truncated (can be null) 1819066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the contents of the file, possibly truncated 1829066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @throws IOException if something goes wrong reading the file 1839066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1849066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static String readTextFile(File file, int max, String ellipsis) throws IOException { 1859066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project InputStream input = new FileInputStream(file); 1869066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project try { 18742471dd5552a346dd82a58a663159875ccc4fb79Dan Egnor long size = file.length(); 18842471dd5552a346dd82a58a663159875ccc4fb79Dan Egnor if (max > 0 || (size > 0 && max == 0)) { // "head" mode: read the first N bytes 18942471dd5552a346dd82a58a663159875ccc4fb79Dan Egnor if (size > 0 && (max == 0 || size < max)) max = (int) size; 1909066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project byte[] data = new byte[max + 1]; 1919066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int length = input.read(data); 1929066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (length <= 0) return ""; 1939066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (length <= max) return new String(data, 0, length); 1949066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (ellipsis == null) return new String(data, 0, max); 1959066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return new String(data, 0, max) + ellipsis; 19642471dd5552a346dd82a58a663159875ccc4fb79Dan Egnor } else if (max < 0) { // "tail" mode: keep the last N 1979066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int len; 1989066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project boolean rolled = false; 1999066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project byte[] last = null, data = null; 2009066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project do { 2019066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (last != null) rolled = true; 2029066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project byte[] tmp = last; last = data; data = tmp; 2039066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (data == null) data = new byte[-max]; 2049066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project len = input.read(data); 2059066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } while (len == data.length); 2069066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 2079066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (last == null && len <= 0) return ""; 2089066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (last == null) return new String(data, 0, len); 2099066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (len > 0) { 2109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project rolled = true; 2119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project System.arraycopy(last, len, last, 0, last.length - len); 2129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project System.arraycopy(data, 0, last, last.length - len, len); 2139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 2149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (ellipsis == null || !rolled) return new String(last); 2159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return ellipsis + new String(last); 21642471dd5552a346dd82a58a663159875ccc4fb79Dan Egnor } else { // "cat" mode: size unknown, read it all in streaming fashion 2179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project ByteArrayOutputStream contents = new ByteArrayOutputStream(); 2189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int len; 2199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project byte[] data = new byte[1024]; 2209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project do { 2219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project len = input.read(data); 2229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project if (len > 0) contents.write(data, 0, len); 2239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } while (len == data.length); 2249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project return contents.toString(); 2259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 2269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } finally { 2279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project input.close(); 2289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 2299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 2306d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville 2316d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville /** 2326d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * Computes the checksum of a file using the CRC32 checksum routine. 2336d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * The value of the checksum is returned. 2346d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * 2356d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * @param file the file to checksum, must not be null 2366d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville * @return the checksum value or an exception is thrown. 2376d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville */ 2386d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville public static long checksumCrc32(File file) throws FileNotFoundException, IOException { 2396d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville CRC32 checkSummer = new CRC32(); 2406d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville CheckedInputStream cis = null; 2416d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville 2426d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville try { 2436d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville cis = new CheckedInputStream( new FileInputStream(file), checkSummer); 2446d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville byte[] buf = new byte[128]; 2456d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville while(cis.read(buf) >= 0) { 2466d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville // Just read for checksum to get calculated. 2476d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } 2486d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville return checkSummer.getValue(); 2496d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } finally { 2506d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville if (cis != null) { 2516d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville try { 2526d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville cis.close(); 2536d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } catch (IOException e) { 2546d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } 2556d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } 2566d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } 2576d25a990afffd5eb385aba3043d5dfad36f1539aWink Saville } 2589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project} 259