值得分享的超全文件工具类FileUtil

结合以前的项目开发中遇到的不同的文件操作，在这里基本上提取出了所遇到过的文件操作的工具类。

1 我项目中用到的文件工具类

1 读取raw文件、file文件，drawable文件，asset文件，比如本地的json数据，本地文本等；
如：string result =fileutil.getstring(context,”raw://first.json”)
2 读取本地的property文件，并转化为hashmap类型的数据 （simpleproperty2hashmap）；
3 将raw文件拷贝到指定目录（copyrawfile）；
4 基本文件读写操作（readfile，writefile）；
5 从文件的完整路径名（路径+文件名）中提取 路径（extractfilepath）；
6 从文件的完整路径名（路径+文件名）中提取文件名(包含扩展名)
如：d:\path\file.ext –> file.ext（extractfilename）
7 检查指定文件的路径是否存在（pathexists）
8 检查制定文件是否存在（fileexists）
9 创建目录（makedir）
10 移除字符串中的bom前缀（removebomheaderifexists）

package com.nsu.edu.library.utils;

import android.content.context;
import android.graphics.bitmap;
import android.graphics.drawable.bitmapdrawable;
import android.text.textutils;

import java.io.bufferedreader;
import java.io.bytearrayinputstream;
import java.io.bytearrayoutputstream;
import java.io.file;
import java.io.fileinputstream;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.inputstream;
import java.io.inputstreamreader;
import java.io.outputstream;
import java.util.hashmap;
import java.util.iterator;
import java.util.properties;
import java.util.set;

/**
 * create by anthony on 2016/1/15
 * class note:文件工具类
 * 包含内容：
 * 1 读取raw文件、file文件，drawable文件，asset文件，比如本地的json数据，本地文本等；
 * 如：string result =fileutil.getstring(context,"raw://first.json")
 * 2 读取本地的property文件，并转化为hashmap类型的数据（simpleproperty2hashmap）；
 * 3 将raw文件拷贝到指定目录（copyrawfile）；
 * 4 基本文件读写操作（readfile，writefile）；
 * 5 从文件的完整路径名（路径+文件名）中提取 路径（extractfilepath）；
 * 6 从文件的完整路径名（路径+文件名）中提取文件名(包含扩展名) 
 如：d:\path\file.ext --> file.ext（extractfilename）
 *7 检查指定文件的路径是否存在（pathexists）
 *8 检查制定文件是否存在（fileexists）
 *9 创建目录（makedir）
 *10 移除字符串中的bom前缀（removebomheaderifexists）
 */
public class fileutil {
 public static final string assets_prefix = "file://android_assets/";
 public static final string assets_prefix2 = "file://android_asset/";
 public static final string assets_prefix3 = "assets://";
 public static final string assets_prefix4 = "asset://";
 public static final string raw_prefix = "file://android_raw/";
 public static final string raw_prefix2 = "raw://";
 public static final string file_prefix = "file://";
 public static final string drawable_prefix = "drawable://";

 public static inputstream getstream(context context, string url) throws ioexception {
  string lowerurl = url.tolowercase();
  inputstream is;
  if (lowerurl.startswith(assets_prefix)) {
   string assetpath = url.substring(assets_prefix.length());
   is = getassetsstream(context, assetpath);
  } else if (lowerurl.startswith(assets_prefix2)) {
   string assetpath = url.substring(assets_prefix2.length());
   is = getassetsstream(context, assetpath);
  } else if (lowerurl.startswith(assets_prefix3)) {
   string assetpath = url.substring(assets_prefix3.length());
   is = getassetsstream(context, assetpath);
  } else if (lowerurl.startswith(assets_prefix4)) {
   string assetpath = url.substring(assets_prefix4.length());
   is = getassetsstream(context, assetpath);
  } else if (lowerurl.startswith(raw_prefix)) {
   string rawname = url.substring(raw_prefix.length());
   is = getrawstream(context, rawname);
  } else if (lowerurl.startswith(raw_prefix2)) {
   string rawname = url.substring(raw_prefix2.length());
   is = getrawstream(context, rawname);
  } else if (lowerurl.startswith(file_prefix)) {
   string filepath = url.substring(file_prefix.length());
   is = getfilestream(filepath);
  } else if (lowerurl.startswith(drawable_prefix)) {
   string drawablename = url.substring(drawable_prefix.length());
   is = getdrawablestream(context, drawablename);
  } else {
   throw new illegalargumentexception(string.format("unsupported url: %s \n" +
     "supported: \n%sxxx\n%sxxx\n%sxxx", url, assets_prefix, raw_prefix, file_prefix));
  }
  return is;
 }

 private static inputstream getassetsstream(context context, string path) throws ioexception {
  return context.getassets().open(path);
 }

 private static inputstream getfilestream(string path) throws ioexception {
  return new fileinputstream(path);
 }

 private static inputstream getrawstream(context context, string rawname) throws ioexception {
  int id = context.getresources().getidentifier(rawname, "raw", context.getpackagename());
  if (id != 0) {
   try {
    return context.getresources().openrawresource(id);
   } catch (exception e) {
    e.printstacktrace();
   }
  }

  throw new ioexception(string.format("raw of id: %s from %s not found", id, rawname));
 }

 private static inputstream getdrawablestream(context context, string rawname) throws ioexception {
  int id = context.getresources().getidentifier(rawname, "drawable", context.getpackagename());
  if (id != 0) {
   bitmapdrawable drawable = (bitmapdrawable) context.getresources().getdrawable(id);
   bitmap bitmap = drawable.getbitmap();

   bytearrayoutputstream os = new bytearrayoutputstream();
   bitmap.compress(bitmap.compressformat.png, 0, os);
   return new bytearrayinputstream(os.tobytearray());
  }

  throw new ioexception(string.format("bitmap of id: %s from %s not found", id, rawname));
 }

 public static string getstring(context context, string url) throws ioexception {
  return getstring(context, url, "utf-8");
 }

 public static string getstring(context context, string url, string encoding) throws ioexception {
  string result = readstreamstring(getstream(context, url), encoding);
  if (result.startswith("\ufeff")) {
   result = result.substring(1);
  }

  return result;
 }

 public static string readstreamstring(inputstream is, string encoding) throws ioexception {
  return new string(readstream(is), encoding);
 }

 public static byte[] readstream(inputstream is) throws ioexception {
  bytearrayoutputstream baos = new bytearrayoutputstream();
  byte[] buf = new byte[1024 * 10];
  int readlen;
  while ((readlen = is.read(buf)) >= 0) {
   baos.write(buf, 0, readlen);
  }
  baos.close();

  return baos.tobytearray();
 }

 public static bitmap getdrawablebitmap(context context, string rawname) {
  int id = context.getresources().getidentifier(rawname, "drawable", context.getpackagename());
  if (id != 0) {
   bitmapdrawable drawable = (bitmapdrawable) context.getresources().getdrawable(id);
   if (drawable != null) {
    return drawable.getbitmap();
   }
  }

  return null;
 }

 /**
  * 读取property文件
  */
 public static hashmap<string, string> simpleproperty2hashmap(context context, string path) {
  try {
   inputstream is = getstream(context, path);
   return simpleproperty2hashmap(is);
  } catch (ioexception e) {
   e.printstacktrace();
  }

  return new hashmap<string, string>();
 }

 private static hashmap<string, string> simpleproperty2hashmap(inputstream in) throws ioexception {
  hashmap<string, string> hashmap = new hashmap<string, string>();
  properties properties = new properties();
  properties.load(in);
  in.close();
  set keyvalue = properties.keyset();
  for (iterator it = keyvalue.iterator(); it.hasnext(); ) {
   string key = (string) it.next();
   hashmap.put(key, (string) properties.get(key));
  }

  return hashmap;
 }

 /**
  * 将raw文件拷贝到指定目录
  */
 public static void copyrawfile(context ctx, string rawfilename, string to) {
  string[] names = rawfilename.split("\\.");
  string tofile = to + "/" + names[0] + "." + names[1];
  file file = new file(tofile);
  if (file.exists()) {
   return;
  }
  try {
   inputstream is = getstream(ctx, "raw://" + names[0]);
   outputstream os = new fileoutputstream(tofile);
   int bytecount = 0;
   byte[] bytes = new byte[1024];

   while ((bytecount = is.read(bytes)) != -1) {
    os.write(bytes, 0, bytecount);
   }
   os.close();
   is.close();
  } catch (exception e) {
   e.printstacktrace();
  }
 }

 /**
  * 基本文件操作
  */
 public static string file_reading_encoding = "utf-8";
 public static string file_writing_encoding = "utf-8";

 public static string readfile(string _sfilename, string _sencoding) throws exception {
  stringbuffer buffcontent = null;
  string sline;

  fileinputstream fis = null;
  bufferedreader buffreader = null;
  if (_sencoding == null || "".equals(_sencoding)) {
   _sencoding = file_reading_encoding;
  }

  try {
   fis = new fileinputstream(_sfilename);
   buffreader = new bufferedreader(new inputstreamreader(fis,
     _sencoding));
   boolean zfirstline = "utf-8".equalsignorecase(_sencoding);
   while ((sline = buffreader.readline()) != null) {
    if (buffcontent == null) {
     buffcontent = new stringbuffer();
    } else {
     buffcontent.append("\n");
    }
    if (zfirstline) {
     sline = removebomheaderifexists(sline);
     zfirstline = false;
    }
    buffcontent.append(sline);
   }// end while
   return (buffcontent == null ? "" : buffcontent.tostring());
  } catch (filenotfoundexception ex) {
   throw new exception("要读取的文件没有找到!", ex);
  } catch (ioexception ex) {
   throw new exception("读取文件时错误!", ex);
  } finally {
   // 增加异常时资源的释放
   try {
    if (buffreader != null)
     buffreader.close();
    if (fis != null)
     fis.close();
   } catch (exception ex) {
    ex.printstacktrace();
   }
  }
 }

 public static file writefile(inputstream is, string path, boolean isoverride) throws exception {
  string spath = extractfilepath(path);
  if (!pathexists(spath)) {
   makedir(spath, true);
  }

  if (!isoverride && fileexists(path)) {
   if(path.contains(".")) {
    string suffix = path.substring(path.lastindexof("."));
    string pre = path.substring(0, path.lastindexof("."));
    path = pre + "_" + timeutils.getnowtime() + suffix;
   } else {
    path = path + "_" + timeutils.getnowtime();
   }
  }

  fileoutputstream os = null;
  file file = null;

  try {
   file = new file(path);
   os = new fileoutputstream(file);
   int bytecount = 0;
   byte[] bytes = new byte[1024];

   while ((bytecount = is.read(bytes)) != -1) {
    os.write(bytes, 0, bytecount);
   }
   os.flush();

   return file;
  } catch (exception e) {
   e.printstacktrace();
   throw new exception("写文件错误", e);
  } finally {
   try {
    if (os != null)
     os.close();
    if (is != null)
     is.close();
   } catch (exception e) {
    e.printstacktrace();
   }
  }
 }

 public static file writefile(string path, string content, string encoding, boolean isoverride) throws exception {
  if (textutils.isempty(encoding)) {
   encoding = file_writing_encoding;
  }
  inputstream is = new bytearrayinputstream(content.getbytes(encoding));
  return writefile(is, path, isoverride);
 }

 /**
  * 从文件的完整路径名（路径+文件名）中提取 路径（包括：drive+directroy )
  *
  * @param _sfilepathname
  * @return
  */
 public static string extractfilepath(string _sfilepathname) {
  int npos = _sfilepathname.lastindexof('/');
  if (npos < 0) {
   npos = _sfilepathname.lastindexof('\\');
  }

  return (npos >= 0 ? _sfilepathname.substring(0, npos + 1) : "");
 }

 /**
  * 从文件的完整路径名（路径+文件名）中提取文件名(包含扩展名) <br>
  * 如：d:\path\file.ext --> file.ext
  *
  * @param _sfilepathname
  * @return
  */
 public static string extractfilename(string _sfilepathname) {
  return extractfilename(_sfilepathname, file.separator);
 }

 /**
  * 从文件的完整路径名（路径+文件名）中提取文件名(包含扩展名) <br>
  * 如：d:\path\file.ext --> file.ext
  *
  * @param _sfilepathname 全文件路径名
  * @param _sfileseparator 文件分隔符
  * @return
  */
 public static string extractfilename(string _sfilepathname,
           string _sfileseparator) {
  int npos = -1;
  if (_sfileseparator == null) {
   npos = _sfilepathname.lastindexof(file.separatorchar);
   if (npos < 0) {
    npos = _sfilepathname
      .lastindexof(file.separatorchar == '/' ? '\\' : '/');
   }
  } else {
   npos = _sfilepathname.lastindexof(_sfileseparator);
  }

  if (npos < 0) {
   return _sfilepathname;
  }

  return _sfilepathname.substring(npos + 1);
 }

 /**
  * 检查指定文件的路径是否存在
  *
  * @param _spathfilename 文件名称(含路径）
  * @return 若存在，则返回true；否则，返回false
  */
 public static boolean pathexists(string _spathfilename) {
  string spath = extractfilepath(_spathfilename);
  return fileexists(spath);
 }

 public static boolean fileexists(string _spathfilename) {
  file file = new file(_spathfilename);
  return file.exists();
 }

 /**
  * 创建目录
  *
  * @param _sdir    目录名称
  * @param _bcreateparentdir 如果父目录不存在，是否创建父目录
  * @return
  */
 public static boolean makedir(string _sdir, boolean _bcreateparentdir) {
  boolean zresult = false;
  file file = new file(_sdir);
  if (_bcreateparentdir)
   zresult = file.mkdirs(); // 如果父目录不存在，则创建所有必需的父目录
  else
   zresult = file.mkdir(); // 如果父目录不存在，不做处理
  if (!zresult)
   zresult = file.exists();
  return zresult;
 }

 /**
  * 移除字符串中的bom前缀
  *
  * @param _sline 需要处理的字符串
  * @return 移除bom后的字符串.
  */
 private static string removebomheaderifexists(string _sline) {
  if (_sline == null) {
   return null;
  }
  string line = _sline;
  if (line.length() > 0) {
   char ch = line.charat(0);
   // 使用while是因为用一些工具看到过某些文件前几个字节都是0xfffe.
   // 0xfeff,0xfffe是字节序的不同处理.jvm中,一般是0xfeff
   while ((ch == 0xfeff || ch == 0xfffe)) {
    line = line.substring(1);
    if (line.length() == 0) {
     break;
    }
    ch = line.charat(0);
   }
  }
  return line;
 }

}

2 网上的工具类

这个工具类也大同小异。其中也有很多和我上面重复的一些方法，也有上面没有的方法。转自trinea的android-common项目。这里直接贴出来，不做任何更改。希望能对看到的人有帮助。也做一个笔记。

package com.nsu.edu.library.utils;

import android.text.textutils;

import java.io.bufferedreader;
import java.io.file;
import java.io.fileinputstream;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.filewriter;
import java.io.ioexception;
import java.io.inputstream;
import java.io.inputstreamreader;
import java.io.outputstream;
import java.util.arraylist;
import java.util.list;

/**
 * file utils
 * <ul>
 * read or write file
 * <li>{@link #readfile(string, string)} read file</li>
 * <li>{@link #readfiletolist(string, string)} read file to string list</li>
 * <li>{@link #writefile(string, string, boolean)} write file from string</li>
 * <li>{@link #writefile(string, string)} write file from string</li>
 * <li>{@link #writefile(string, list, boolean)} write file from string list</li>
 * <li>{@link #writefile(string, list)} write file from string list</li>
 * <li>{@link #writefile(string, inputstream)} write file</li>
 * <li>{@link #writefile(string, inputstream, boolean)} write file</li>
 * <li>{@link #writefile(file, inputstream)} write file</li>
 * <li>{@link #writefile(file, inputstream, boolean)} write file</li>
 * </ul>
 * <ul>
 * operate file
 * <li>{@link #movefile(file, file)} or {@link #movefile(string, string)}</li>
 * <li>{@link #copyfile(string, string)}</li>
 * <li>{@link #getfileextension(string)}</li>
 * <li>{@link #getfilename(string)}</li>
 * <li>{@link #getfilenamewithoutextension(string)}</li>
 * <li>{@link #getfilesize(string)}</li>
 * <li>{@link #deletefile(string)}</li>
 * <li>{@link #isfileexist(string)}</li>
 * <li>{@link #isfolderexist(string)}</li>
 * <li>{@link #makefolders(string)}</li>
 * <li>{@link #makedirs(string)}</li>
 * </ul>
 * 
 * @author <a href="http://www.trinea.cn" rel="external nofollow" target="_blank">trinea</a> 2012-5-12
 */
public class fileutils {

 public final static string file_extension_separator = ".";

 private fileutils() {
  throw new assertionerror();
 }

 /**
  * read file
  * 
  * @param filepath
  * @param charsetname the name of a supported {@link java.nio.charset.charset </code>charset<code>}
  * @return if file not exist, return null, else return content of file
  * @throws runtimeexception if an error occurs while operator bufferedreader
  */
 public static stringbuilder readfile(string filepath, string charsetname) {
  file file = new file(filepath);
  stringbuilder filecontent = new stringbuilder("");
  if (file == null || !file.isfile()) {
   return null;
  }

  bufferedreader reader = null;
  try {
   inputstreamreader is = new inputstreamreader(new fileinputstream(file), charsetname);
   reader = new bufferedreader(is);
   string line = null;
   while ((line = reader.readline()) != null) {
    if (!filecontent.tostring().equals("")) {
     filecontent.append("\r\n");
    }
    filecontent.append(line);
   }
   return filecontent;
  } catch (ioexception e) {
   throw new runtimeexception("ioexception occurred. ", e);
  } finally {
   ioutils.close(reader);
  }
 }

 /**
  * write file
  * 
  * @param filepath
  * @param content
  * @param append is append, if true, write to the end of file, else clear content of file and write into it
  * @return return false if content is empty, true otherwise
  * @throws runtimeexception if an error occurs while operator filewriter
  */
 public static boolean writefile(string filepath, string content, boolean append) {
  if (stringutils.isempty(content)) {
   return false;
  }

  filewriter filewriter = null;
  try {
   makedirs(filepath);
   filewriter = new filewriter(filepath, append);
   filewriter.write(content);
   return true;
  } catch (ioexception e) {
   throw new runtimeexception("ioexception occurred. ", e);
  } finally {
   ioutils.close(filewriter);
  }
 }

 /**
  * write file
  * 
  * @param filepath
  * @param contentlist
  * @param append is append, if true, write to the end of file, else clear content of file and write into it
  * @return return false if contentlist is empty, true otherwise
  * @throws runtimeexception if an error occurs while operator filewriter
  */
 public static boolean writefile(string filepath, list<string> contentlist, boolean append) {
  if (listutils.isempty(contentlist)) {
   return false;
  }

  filewriter filewriter = null;
  try {
   makedirs(filepath);
   filewriter = new filewriter(filepath, append);
   int i = 0;
   for (string line : contentlist) {
    if (i++ > 0) {
     filewriter.write("\r\n");
    }
    filewriter.write(line);
   }
   return true;
  } catch (ioexception e) {
   throw new runtimeexception("ioexception occurred. ", e);
  } finally {
   ioutils.close(filewriter);
  }
 }

 /**
  * write file, the string will be written to the begin of the file
  * 
  * @param filepath
  * @param content
  * @return
  */
 public static boolean writefile(string filepath, string content) {
  return writefile(filepath, content, false);
 }

 /**
  * write file, the string list will be written to the begin of the file
  * 
  * @param filepath
  * @param contentlist
  * @return
  */
 public static boolean writefile(string filepath, list<string> contentlist) {
  return writefile(filepath, contentlist, false);
 }

 /**
  * write file, the bytes will be written to the begin of the file
  * 
  * @param filepath
  * @param stream
  * @return
  * @see {@link #writefile(string, inputstream, boolean)}
  */
 public static boolean writefile(string filepath, inputstream stream) {
  return writefile(filepath, stream, false);
 }

 /**
  * write file
  * 
  * @param file the file to be opened for writing.
  * @param stream the input stream
  * @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning
  * @return return true
  * @throws runtimeexception if an error occurs while operator fileoutputstream
  */
 public static boolean writefile(string filepath, inputstream stream, boolean append) {
  return writefile(filepath != null ? new file(filepath) : null, stream, append);
 }

 /**
  * write file, the bytes will be written to the begin of the file
  * 
  * @param file
  * @param stream
  * @return
  * @see {@link #writefile(file, inputstream, boolean)}
  */
 public static boolean writefile(file file, inputstream stream) {
  return writefile(file, stream, false);
 }

 /**
  * write file
  * 
  * @param file the file to be opened for writing.
  * @param stream the input stream
  * @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning
  * @return return true
  * @throws runtimeexception if an error occurs while operator fileoutputstream
  */
 public static boolean writefile(file file, inputstream stream, boolean append) {
  outputstream o = null;
  try {
   makedirs(file.getabsolutepath());
   o = new fileoutputstream(file, append);
   byte data[] = new byte[1024];
   int length = -1;
   while ((length = stream.read(data)) != -1) {
    o.write(data, 0, length);
   }
   o.flush();
   return true;
  } catch (filenotfoundexception e) {
   throw new runtimeexception("filenotfoundexception occurred. ", e);
  } catch (ioexception e) {
   throw new runtimeexception("ioexception occurred. ", e);
  } finally {
   ioutils.close(o);
   ioutils.close(stream);
  }
 }

 /**
  * move file
  * 
  * @param sourcefilepath
  * @param destfilepath
  */
 public static void movefile(string sourcefilepath, string destfilepath) {
  if (textutils.isempty(sourcefilepath) || textutils.isempty(destfilepath)) {
   throw new runtimeexception("both sourcefilepath and destfilepath cannot be null.");
  }
  movefile(new file(sourcefilepath), new file(destfilepath));
 }

 /**
  * move file
  * 
  * @param srcfile
  * @param destfile
  */
 public static void movefile(file srcfile, file destfile) {
  boolean rename = srcfile.renameto(destfile);
  if (!rename) {
   copyfile(srcfile.getabsolutepath(), destfile.getabsolutepath());
   deletefile(srcfile.getabsolutepath());
  }
 }

 /**
  * copy file
  * 
  * @param sourcefilepath
  * @param destfilepath
  * @return
  * @throws runtimeexception if an error occurs while operator fileoutputstream
  */
 public static boolean copyfile(string sourcefilepath, string destfilepath) {
  inputstream inputstream = null;
  try {
   inputstream = new fileinputstream(sourcefilepath);
  } catch (filenotfoundexception e) {
   throw new runtimeexception("filenotfoundexception occurred. ", e);
  }
  return writefile(destfilepath, inputstream);
 }

 /**
  * read file to string list, a element of list is a line
  * 
  * @param filepath
  * @param charsetname the name of a supported {@link java.nio.charset.charset </code>charset<code>}
  * @return if file not exist, return null, else return content of file
  * @throws runtimeexception if an error occurs while operator bufferedreader
  */
 public static list<string> readfiletolist(string filepath, string charsetname) {
  file file = new file(filepath);
  list<string> filecontent = new arraylist<string>();
  if (file == null || !file.isfile()) {
   return null;
  }

  bufferedreader reader = null;
  try {
   inputstreamreader is = new inputstreamreader(new fileinputstream(file), charsetname);
   reader = new bufferedreader(is);
   string line = null;
   while ((line = reader.readline()) != null) {
    filecontent.add(line);
   }
   return filecontent;
  } catch (ioexception e) {
   throw new runtimeexception("ioexception occurred. ", e);
  } finally {
   ioutils.close(reader);
  }
 }

 /**
  * get file name from path, not include suffix
  * 
  * <pre>
  *  getfilenamewithoutextension(null)    = null
  *  getfilenamewithoutextension("")     = ""
  *  getfilenamewithoutextension(" ")    = " "
  *  getfilenamewithoutextension("abc")    = "abc"
  *  getfilenamewithoutextension("a.mp3")   = "a"
  *  getfilenamewithoutextension("a.b.rmvb")   = "a.b"
  *  getfilenamewithoutextension("c:\\")    = ""
  *  getfilenamewithoutextension("c:\\a")    = "a"
  *  getfilenamewithoutextension("c:\\a.b")   = "a"
  *  getfilenamewithoutextension("c:a.txt\\a")  = "a"
  *  getfilenamewithoutextension("/home/admin")  = "admin"
  *  getfilenamewithoutextension("/home/admin/a.txt/b.mp3") = "b"
  * </pre>
  * 
  * @param filepath
  * @return file name from path, not include suffix
  * @see
  */
 public static string getfilenamewithoutextension(string filepath) {
  if (stringutils.isempty(filepath)) {
   return filepath;
  }

  int extenposi = filepath.lastindexof(file_extension_separator);
  int fileposi = filepath.lastindexof(file.separator);
  if (fileposi == -1) {
   return (extenposi == -1 ? filepath : filepath.substring(0, extenposi));
  }
  if (extenposi == -1) {
   return filepath.substring(fileposi + 1);
  }
  return (fileposi < extenposi ? filepath.substring(fileposi + 1, extenposi) : filepath.substring(fileposi + 1));
 }

 /**
  * get file name from path, include suffix
  * 
  * <pre>
  *  getfilename(null)    = null
  *  getfilename("")     = ""
  *  getfilename(" ")    = " "
  *  getfilename("a.mp3")   = "a.mp3"
  *  getfilename("a.b.rmvb")   = "a.b.rmvb"
  *  getfilename("abc")    = "abc"
  *  getfilename("c:\\")    = ""
  *  getfilename("c:\\a")    = "a"
  *  getfilename("c:\\a.b")   = "a.b"
  *  getfilename("c:a.txt\\a")  = "a"
  *  getfilename("/home/admin")  = "admin"
  *  getfilename("/home/admin/a.txt/b.mp3") = "b.mp3"
  * </pre>
  * 
  * @param filepath
  * @return file name from path, include suffix
  */
 public static string getfilename(string filepath) {
  if (stringutils.isempty(filepath)) {
   return filepath;
  }

  int fileposi = filepath.lastindexof(file.separator);
  return (fileposi == -1) ? filepath : filepath.substring(fileposi + 1);
 }

 /**
  * get folder name from path
  * 
  * <pre>
  *  getfoldername(null)    = null
  *  getfoldername("")     = ""
  *  getfoldername(" ")    = ""
  *  getfoldername("a.mp3")   = ""
  *  getfoldername("a.b.rmvb")   = ""
  *  getfoldername("abc")    = ""
  *  getfoldername("c:\\")    = "c:"
  *  getfoldername("c:\\a")    = "c:"
  *  getfoldername("c:\\a.b")   = "c:"
  *  getfoldername("c:a.txt\\a")  = "c:a.txt"
  *  getfoldername("c:a\\b\\c\\d.txt") = "c:a\\b\\c"
  *  getfoldername("/home/admin")  = "/home"
  *  getfoldername("/home/admin/a.txt/b.mp3") = "/home/admin/a.txt"
  * </pre>
  * 
  * @param filepath
  * @return
  */
 public static string getfoldername(string filepath) {

  if (stringutils.isempty(filepath)) {
   return filepath;
  }

  int fileposi = filepath.lastindexof(file.separator);
  return (fileposi == -1) ? "" : filepath.substring(0, fileposi);
 }

 /**
  * get suffix of file from path
  * 
  * <pre>
  *  getfileextension(null)    = ""
  *  getfileextension("")     = ""
  *  getfileextension(" ")    = " "
  *  getfileextension("a.mp3")   = "mp3"
  *  getfileextension("a.b.rmvb")   = "rmvb"
  *  getfileextension("abc")    = ""
  *  getfileextension("c:\\")    = ""
  *  getfileextension("c:\\a")    = ""
  *  getfileextension("c:\\a.b")   = "b"
  *  getfileextension("c:a.txt\\a")  = ""
  *  getfileextension("/home/admin")  = ""
  *  getfileextension("/home/admin/a.txt/b") = ""
  *  getfileextension("/home/admin/a.txt/b.mp3") = "mp3"
  * </pre>
  * 
  * @param filepath
  * @return
  */
 public static string getfileextension(string filepath) {
  if (stringutils.isblank(filepath)) {
   return filepath;
  }

  int extenposi = filepath.lastindexof(file_extension_separator);
  int fileposi = filepath.lastindexof(file.separator);
  if (extenposi == -1) {
   return "";
  }
  return (fileposi >= extenposi) ? "" : filepath.substring(extenposi + 1);
 }

 /**
  * creates the directory named by the trailing filename of this file, including the complete directory path required
  * to create this directory. <br/>
  * <br/>
  * <ul>
  * <strong>attentions:</strong>
  * <li>makedirs("c:\\users\\trinea") can only create users folder</li>
  * <li>makefolder("c:\\users\\trinea\\") can create trinea folder</li>
  * </ul>
  * 
  * @param filepath
  * @return true if the necessary directories have been created or the target directory already exists, false one of
  *   the directories can not be created.
  *   <ul>
  *   <li>if {@link fileutils#getfoldername(string)} return null, return false</li>
  *   <li>if target directory already exists, return true</li>
  *   <li>return {@link file#makefolder}</li>
  *   </ul>
  */
 public static boolean makedirs(string filepath) {
  string foldername = getfoldername(filepath);
  if (stringutils.isempty(foldername)) {
   return false;
  }

  file folder = new file(foldername);
  return (folder.exists() && folder.isdirectory()) ? true : folder.mkdirs();
 }

 /**
  * @param filepath
  * @return
  * @see #makedirs(string)
  */
 public static boolean makefolders(string filepath) {
  return makedirs(filepath);
 }

 /**
  * indicates if this file represents a file on the underlying file system.
  * 
  * @param filepath
  * @return
  */
 public static boolean isfileexist(string filepath) {
  if (stringutils.isblank(filepath)) {
   return false;
  }

  file file = new file(filepath);
  return (file.exists() && file.isfile());
 }

 /**
  * indicates if this file represents a directory on the underlying file system.
  * 
  * @param directorypath
  * @return
  */
 public static boolean isfolderexist(string directorypath) {
  if (stringutils.isblank(directorypath)) {
   return false;
  }

  file dire = new file(directorypath);
  return (dire.exists() && dire.isdirectory());
 }

 /**
  * delete file or directory
  * <ul>
  * <li>if path is null or empty, return true</li>
  * <li>if path not exist, return true</li>
  * <li>if path exist, delete recursion. return true</li>
  * <ul>
  * 
  * @param path
  * @return
  */
 public static boolean deletefile(string path) {
  if (stringutils.isblank(path)) {
   return true;
  }

  file file = new file(path);
  if (!file.exists()) {
   return true;
  }
  if (file.isfile()) {
   return file.delete();
  }
  if (!file.isdirectory()) {
   return false;
  }
  for (file f : file.listfiles()) {
   if (f.isfile()) {
    f.delete();
   } else if (f.isdirectory()) {
    deletefile(f.getabsolutepath());
   }
  }
  return file.delete();
 }

 /**
  * get file size
  * <ul>
  * <li>if path is null or empty, return -1</li>
  * <li>if path exist and it is a file, return file size, else return -1</li>
  * <ul>
  * 
  * @param path
  * @return returns the length of this file in bytes. returns -1 if the file does not exist.
  */
 public static long getfilesize(string path) {
  if (stringutils.isblank(path)) {
   return -1;
  }

  file file = new file(path);
  return (file.exists() && file.isfile() ? file.length() : -1);
 }
}

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