FileUtils如何实现长尾词的智能处理和高效检索？

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gistfile1.txt**文件操作工具类**@author xuan@version $Revision: 1.0 $$Date: 2013-9-4 下午7:24:34 $**public abstract class FileUtils { public static final String EMPTY=; public static final long ONE_KB=1024; public ...}**/

gistfile1.txt

/** * 文件操作工具类 * * @author xuan * @version $Revision: 1.0 $, $Date: 2013-9-4 下午7:24:34 $ */ public abstract class FileUtils { public static final String EMPTY = ""; public static final long ONE_KB = 1024; public static final long ONE_MB = ONE_KB * ONE_KB; public static final long ONE_GB = ONE_KB * ONE_MB; public static final long ONE_TB = ONE_KB * ONE_GB; public static final long ONE_PB = ONE_KB * ONE_TB; public static final long ONE_EB = ONE_KB * ONE_PB; private static final long FILE_COPY_BUFFER_SIZE = ONE_MB * 30; /** * 截取文件的后缀名，例如文件名是xuan.jpg时，返回的后缀名时jpg * * @param fileName 文件名 * @return 后缀名 */ public static String getExtension(String fileName) { if (null == fileName) { return EMPTY; } int pointIndex = fileName.lastIndexOf("."); return pointIndex > 0 && pointIndex < fileName.length() ? fileName .substring(pointIndex + 1).toLowerCase() : EMPTY; } // ////////////////////字节写入读出文件方法，一般可以用来写图片，声音等//////////////////// /** * 字节写入到文件中 * * @param file 文件 * @param data 字节数据 * @param append 是否从文件后面添加 * @throws IOException */ public static void writeByteArrayToFile(File file, byte[] data, boolean append) throws IOException { OutputStream out = null; try { out = openOutputStream(file, append); out.write(data); } finally { IOUtils.closeQuietly(out); } } /** * 读出文件中的字节 * * @param file 文件 * @return 字节数组 * @throws IOException */ public static byte[] readFileToByteArray(File file) throws IOException { InputStream in = null; try { in = openInputStream(file); return IOUtils.toByteArray(in, file.length()); } finally { IOUtils.closeQuietly(in); } } // ////////////////////字符串从文件中写入读出方法//////////////////// /** * 数据写入文件 * * @param file 要写入的文件 * @param data 数据 * @param encoding 指定编码 * @param append 是否追加 * @throws IOException */ public static void writeStringToFile(File file, String data, String encoding, boolean append) throws IOException { OutputStream out = null; try { out = openOutputStream(file, append); IOUtils.write(data, out, encoding); } finally { IOUtils.closeQuietly(out); } } /** * 从文件中以指定编码读取成字符串 * * @param file 文件 * @param encoding 编码 * @return * @throws IOException */ public static String readFileToString(File file, String encoding) throws IOException { InputStream in = null; try { in = openInputStream(file); return IOUtils.toString(in, encoding); } finally { IOUtils.closeQuietly(in); } } // ////////////////////打开输入输出流方法//////////////////// /** * 打开一个文件的写入流，文件不存在会自动创建 * * @param file 文件 * @param append 是否以追加的方式写入 * @return * @throws IOException */ public static FileOutputStream openOutputStream(File file, boolean append) throws IOException { if (file.exists()) { if (file.isDirectory()) { throw new IOException("File '" + file + "' exists but is a directory"); } if (file.canWrite() == false) { throw new IOException("File '" + file + "' cannot be written to"); } } else { File parent = file.getParentFile(); if (parent != null) { if (!parent.mkdirs() && !parent.isDirectory()) { throw new IOException("Directory '" + parent + "' could not be created"); } } } return new FileOutputStream(file, append); } /** * 打开文件输入流，校验友好的提示 * * @param file 要打开的文件 * @return * @throws IOException */ public static FileInputStream openInputStream(File file) throws IOException { if (file.exists()) { if (file.isDirectory()) { throw new IOException("File '" + file + "' exists but is a directory"); } if (file.canRead() == false) { throw new IOException("File '" + file + "' cannot be read"); } } else { throw new FileNotFoundException("File '" + file + "' does not exist"); } return new FileInputStream(file); } // ////////////////////文件单位字节友好输出//////////////////// /** * 友好的显示单位，舍弃有点问题，例如：byteCountToDisplaySize(2047)显示1K，明显是舍弃了 * * @param size byte单位值 * @return */ public static String byteCountToDisplaySize(long size) { String displaySize; if (size / ONE_EB > 0) { displaySize = String.valueOf(size / ONE_EB) + " EB"; } else if (size / ONE_EB > 0) { displaySize = String.valueOf(size / ONE_EB) + " PB"; } else if (size / ONE_TB > 0) { displaySize = String.valueOf(size / ONE_TB) + " TB"; } else if (size / ONE_GB > 0) { displaySize = String.valueOf(size / ONE_GB) + " GB"; } else if (size / ONE_MB > 0) { displaySize = String.valueOf(size / ONE_MB) + " MB"; } else if (size / ONE_KB > 0) { displaySize = String.valueOf(size / ONE_KB) + " KB"; } else { displaySize = String.valueOf(size) + " bytes"; } return displaySize; } // ////////////////////移动文件//////////////////// /** * 剪切文件夹到文件夹 * * @param src 源文件夹 * @param destDir 目的文件夹 * @param isCover 存在是否覆盖 * @throws IOException */ public static void moveDirectoryToDirectory(File src, File destDir, boolean isCover) throws IOException { if (src == null) { throw new NullPointerException("Source must not be null"); } if (destDir == null) { throw new NullPointerException( "Destination directory must not be null"); } if (destDir.exists()) { if (isCover) { deleteFileOrDirectoryQuietly(destDir.getPath()); } else { throw new IOException( "Destination directory is exists and isCover=false"); } } destDir.mkdirs(); if (!destDir.exists()) { throw new FileNotFoundException("Destination directory '" + destDir + "' create failed]"); } if (!destDir.isDirectory()) { throw new IOException("Destination '" + destDir + "' is not a directory"); } boolean rename = src.renameTo(destDir); if (!rename) { if (destDir.getCanonicalPath().startsWith(src.getCanonicalPath())) { throw new IOException("Cannot move directory: " + src + " to a subdirectory of itself: " + destDir); } copyDirectoryToDirectory(src, destDir); deleteFileOrDirectoryQuietly(src.getPath()); if (src.exists()) { throw new IOException("Failed to delete original directory '" + src + "' after copy to '" + destDir + "'"); } } } /** * 剪切文件到文件夹 * * @param srcFile 源文件 * @param destDir 目的文件夹 * @param isCover 存在是否覆盖 * @throws IOException */ public static void moveFileToDirectory(File srcFile, File destDir, boolean isCover) throws IOException { if (srcFile == null) { throw new NullPointerException("Source must not be null"); } if (destDir == null) { throw new NullPointerException( "Destination directory must not be null"); } if (!destDir.exists()) { destDir.mkdirs(); } if (!destDir.exists()) { throw new FileNotFoundException("Destination directory '" + destDir + "' create failed]"); } if (!destDir.isDirectory()) { throw new IOException("Destination '" + destDir + "' is not a directory"); } moveFile(srcFile, new File(destDir, srcFile.getName()), isCover); } /** * 剪切文件到文件 * * @param srcFile 源文件 * @param destFile 目的文件 * @param isCover 存在是否覆盖 * @throws IOException */ public static void moveFile(File srcFile, File destFile, boolean isCover) throws IOException { if (null == srcFile) { throw new NullPointerException("Source must not be null"); } if (null == destFile) { throw new NullPointerException("Destination must not be null"); } if (!srcFile.exists()) { throw new FileNotFoundException("Source '" + srcFile + "' does not exist"); } if (srcFile.isDirectory()) { throw new IOException("Source '" + srcFile + "' is a directory"); } if (destFile.isDirectory()) { throw new IOException("Destination '" + destFile + "' is a directory"); } if (destFile.exists()) { if (isCover) { deleteFileOrDirectoryQuietly(destFile.getPath()); } else { throw new IOException( "Destination directory is exists and isCover=false"); } } boolean rename = srcFile.renameTo(destFile); if (!rename) { copyFile(srcFile, destFile); if (!srcFile.delete()) { deleteFileOrDirectoryQuietly(destFile.getPath()); throw new IOException("Failed to delete original file '" + srcFile + "' after copy to '" + destFile + "'"); } } } // ////////////////////文件夹内容拷贝到指定文件夹中//////////////////// /** * 拷贝文件夹到文件夹 * * @param srcDir 源文件夹 * @param destDir 目的文件夹 * @throws IOException */ public static void copyDirectoryToDirectory(File srcDir, File destDir) throws IOException { copyDirectoryToDirectory(srcDir, new File(destDir, srcDir.getName()), null); } /** * 拷贝文件夹到文件夹 * * @param srcDir 源文件夹 * @param destDir 目的文件夹 * @param filter 文件过滤器 * @throws IOException */ public static void copyDirectoryToDirectory(File srcDir, File destDir, FileFilter filter) throws IOException { if (srcDir == null) { throw new NullPointerException("Source must not be null"); } if (destDir == null) { throw new NullPointerException("Destination must not be null"); } if (srcDir.exists() && !srcDir.isDirectory()) { throw new IllegalArgumentException("Source '" + destDir + "' is not a directory"); } if (destDir.exists() && !destDir.isDirectory()) { throw new IllegalArgumentException("Destination '" + destDir + "' is not a directory"); } if (!srcDir.exists()) { throw new FileNotFoundException("Source '" + srcDir + "' does not exist"); } if (srcDir.getCanonicalPath().equals(destDir.getCanonicalPath())) { throw new IOException("Source '" + srcDir + "' and destination '" + destDir + "' are the same"); } // Cater for destination being directory within the source directory // (see IO-141) List exclusionList = null; if (destDir.getCanonicalPath().startsWith(srcDir.getCanonicalPath())) { File[] srcFiles = null == filter ? srcDir.listFiles() : srcDir .listFiles(filter); if (srcFiles != null && srcFiles.length > 0) { exclusionList = new ArrayList (srcFiles.length); for (File srcFile : srcFiles) { File copiedFile = new File(destDir, srcFile.getName()); exclusionList.add(copiedFile.getCanonicalPath()); } } } doCopyDirectory(srcDir, destDir, filter, true, exclusionList); } private static void doCopyDirectory(File srcDir, File destDir, FileFilter filter, boolean preserveFileDate, List exclusionList) throws IOException { // recurse File[] srcFiles = (null == filter) ? srcDir.listFiles() : srcDir .listFiles(filter); if (srcFiles == null) { // null if abstract pathname does not denote a // directory, or if an I/O error occurs throw new IOException("Failed to list contents of " + srcDir); } if (destDir.exists()) { if (!destDir.isDirectory()) { throw new IOException("Destination '" + destDir + "' exists but is not a directory"); } } else { if (!destDir.mkdirs() && !destDir.isDirectory()) { throw new IOException("Destination '" + destDir + "' directory cannot be created"); } } if (!destDir.canWrite()) { throw new IOException("Destination '" + destDir + "' cannot be written to"); } for (File srcFile : srcFiles) { File dstFile = new File(destDir, srcFile.getName()); if (exclusionList == null || !exclusionList.contains(srcFile.getCanonicalPath())) { if (srcFile.isDirectory()) { doCopyDirectory(srcFile, dstFile, filter, preserveFileDate, exclusionList); } else { doCopyFile(srcFile, dstFile, preserveFileDate); } } } if (preserveFileDate) { destDir.setLastModified(srcDir.lastModified()); } } // ////////////////////文件拷贝到指定文件夹里//////////////////// /** * 拷贝文件到文件夹 * * @param srcFile 源文件 * @param destDir 目的文件夹 * @throws IOException */ public static void copyFileToDirectory(File srcFile, File destDir) throws IOException { copyFileToDirectory(srcFile, destDir, true); } /** * 拷贝文件到文件夹 * * @param srcFile 源文件 * @param destDir 目的文件夹 * @param preserveFileDate 是否修改时间 * @throws IOException */ public static void copyFileToDirectory(File srcFile, File destDir, boolean preserveFileDate) throws IOException { if (null == destDir) { throw new NullPointerException("Destination must not be null"); } if (destDir.exists() && !destDir.isDirectory()) { throw new IllegalArgumentException("Destination '" + destDir + "' is not a directory"); } File destFile = new File(destDir, srcFile.getName()); copyFile(srcFile, destFile, preserveFileDate); } // ////////////////////文件拷贝到文件//////////////////// /** * 拷贝文件到文件 * * @param srcFile 源文件 * @param destFile 目的文件 * @throws IOException */ public static void copyFile(File srcFile, File destFile) throws IOException { copyFile(srcFile, destFile, true); } /** * 拷贝文件到文件 * * @param srcFile 源文件 * @param destFile 目的文件 * @param preserveFileDate 是否修改时间 * @throws IOException */ public static void copyFile(File srcFile, File destFile, boolean preserveFileDate) throws IOException { if (srcFile == null) { throw new NullPointerException("Source must not be null"); } if (destFile == null) { throw new NullPointerException("Destination must not be null"); } if (!srcFile.exists()) {// 源不存在 throw new FileNotFoundException("Source '" + srcFile + "' does not exist"); } if (destFile.isDirectory()) {// 源存在，但是是个目录 throw new IOException("Destination '" + destFile + "' exists but is a directory"); } if (srcFile.getCanonicalPath().equals(destFile.getCanonicalPath())) {// 指向了同一个文件 throw new IOException("Source '" + srcFile + "' and destination '" + destFile + "' are the same"); } if (destFile.exists() && !destFile.canWrite()) {// 目标文件存在，没有写权限 throw new IOException("Destination '" + destFile + "' exists but is read-only"); } // 创建父文件夹 File parentFile = destFile.getParentFile(); if (null != parentFile) { if (!parentFile.mkdirs() && !parentFile.isDirectory()) { throw new IOException("Destination '" + parentFile + "' directory cannot be created"); } } doCopyFile(srcFile, destFile, preserveFileDate); } private static void doCopyFile(File srcFile, File destFile, boolean preserveFileDate) throws IOException { FileInputStream fis = null; FileOutputStream fos = null; FileChannel input = null; FileChannel output = null; try { fis = new FileInputStream(srcFile); fos = new FileOutputStream(destFile); input = fis.getChannel(); output = fos.getChannel(); long size = input.size(); long pos = 0; long count = 0; while (pos < size) { count = size - pos > FILE_COPY_BUFFER_SIZE ? FILE_COPY_BUFFER_SIZE : size - pos; pos += output.transferFrom(input, pos, count); } } finally { IOUtils.closeQuietly(output); IOUtils.closeQuietly(fos); IOUtils.closeQuietly(input); IOUtils.closeQuietly(fis); } if (srcFile.length() != destFile.length()) { throw new IOException("Failed to copy full contents from '" + srcFile + "' to '" + destFile + "'"); } if (preserveFileDate) {// 修改文件最后修改时间 destFile.setLastModified(srcFile.lastModified()); } } // ////////////////////递归删除文件夹下的所有文件//////////////////// /** * 删除指定目录下文件及目录，默认本身也会被删除 * * @param filePath 文件或者文件夹路径 */ public static void deleteFileOrDirectoryQuietly(String filePath) { try { deleteFileOrDirectory(filePath, true); } catch (Exception e) { // Ignore } } /** * 删除指定目录下文件及目录 * * @param filePath 文件或者文件夹路径 * @param deleteThisPath 是否需要删除这个本身指定的文件或者文件夹 */ public static void deleteFileOrDirectory(String filePath, boolean deleteThisPath) throws IOException { if (null != filePath && filePath.length() > 0) { File file = new File(filePath); if (file.isDirectory()) {// 处理目录 File files[] = file.listFiles(); for (int i = 0; i < files.length; i++) { deleteFileOrDirectory(files[i].getAbsolutePath(), true); } } if (deleteThisPath) { if (!file.isDirectory()) {// 如果是文件，删除 file.delete(); } else {// 目录 if (file.listFiles().length == 0) {// 目录下没有文件或者目录，删除 file.delete(); } } } } } // ////////////////////递归获取文件夹下面的所有文件//////////////////// /** * 获取指定路径下的所有文件 * * @param path 指定路径 * @return */ public static List getFileListByPath(String path) { return getFileListByPath(path, null); } /** * 获取指定路径下的所有文件 * * @param path 指定路径 * @param filter 文件过滤器 * @return */ public static List getFileListByPath(String path, FileFilter filter) { File directory = new File(path); if (!directory.exists() || !directory.isDirectory()) { throw new IllegalArgumentException("Nonexistent directory[" + path + "]"); } return new Recursiver().getFileList(directory, filter); } // ////////////////////操作Properties文件//////////////////// /** * 读取指定路径的Properties文件 * * @param path 路径 * @return Properties对象 */ public static Properties readProperties(String path) { File file = new File(path); if (!file.exists()) { return null; } Properties properties = new Properties(); InputStream in = null; try { in = new FileInputStream(file); properties.load(in); } catch (IOException e) { throw new RuntimeException("Could not read Properties[" + path + "]", e); } finally { IOUtils.closeQuietly(in); } return properties; } /** * 从输入流读取Properties对象 * * @param in 输入流 * @return Properties对象 */ public static Properties readProperties(InputStream in) { Properties properties = new Properties(); try { properties.load(in); } catch (IOException e) { throw new RuntimeException("Could not read Properties", e); } finally { IOUtils.closeQuietly(in); } return properties; } /** * 把Properties对象写到指定路径的文件里 * * @param path 路进 * @param properties Properties对象 */ public static void writeProperties(String path, Properties properties) { OutputStream out = null; try { out = new FileOutputStream(path); properties.store(out, null); } catch (IOException e) { throw new RuntimeException("Could not write Properties[" + path + "]", e); } finally { IOUtils.closeQuietly(out); } } /** * 递归获取指定目录下的所有文件的遍历器 * * @author xuan * @version $Revision: 1.0 $, $Date: 2013-9-5 下午1:13:17 $ */ private static class Recursiver { private static ArrayList files = new ArrayList (); public List getFileList(File file, FileFilter filter) { File children[] = null == filter ? file.listFiles() : file .listFiles(filter); for (int i = 0; i < children.length; i++) { if (children[i].isDirectory()) { new Recursiver().getFileList(children[i], filter); } else { files.add(children[i]); } } return files; } } } 更多：github.com/xuan698400/xutils