FileHelper-文件操作工具

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 javax.servlet.http.HttpServletResponse; public class FileHelper {          static File file ;               /**           * @删除文件           * input 输入 output 输出           * */          public static boolean deleteFile(String url){                                      boolean flag = false;                                      try{                             if(null == file){                                                                         file = new File(url);                                                                          if(file.isFile()){                                                                                              if(file.canWrite()){                                                                                                                file.delete();                                                }                                                                                            flag = true;                                                                                    }                             }else{                                                                          if(url == file.getPath()){                                                                                              file.delete();                                                                                              flag = true;                                      }                             }                                               }catch(Exception e){                                                        flag = false ;                                                        e.printStackTrace();                    }finally{                                                        file = null;                                                        System.gc();                    }                    return flag;          }                   /**      * 新建目录      * @param folderPath String 如 c:/fqf      * @return boolean      */    public static void newFolder(String folderPath) {        try {            String filePath = folderPath;            filePath = filePath.toString();            java.io.File myFilePath = new java.io.File(filePath);            if (!myFilePath.exists()) {                myFilePath.mkdir();            }        }        catch (Exception e) {            e.printStackTrace();        }    }                            /**      * 复制单个文件      * @param oldPath String 原文件路径 如：c:/fqf.txt      * @param newPath String 复制后路径 如：f:/fqf.txt      * @return boolean      */    public static void copyFile(String oldPath, String newPath) {        try {            int bytesum = 0;            int byteread = 0;            File oldfile = new File(oldPath);            if (oldfile.exists()) { //文件存在时                InputStream inStream = new FileInputStream(oldPath); //读入原文件                FileOutputStream fs = new FileOutputStream(newPath);                byte[] buffer = new byte[1444];                int length;                while ( (byteread = inStream.read(buffer)) != -1) {                    bytesum += byteread; //字节数 文件大小                    fs.write(buffer, 0, byteread);                }                inStream.close();                fs.close();            }        }        catch (Exception e) {            e.printStackTrace();        }    } /**        * 使用文件通道的方式复制文件      * @param s  源文件      * @param t  复制到的新文件      */      public static void fileChannelCopy(String srcPath,String outpath) {        File s = new File(srcPath);        File t = new File(outpath);          FileInputStream fi = null;          FileOutputStream fo = null;          FileChannel in = null;          FileChannel out = null;          try {              fi = new FileInputStream(s);              fo = new FileOutputStream(t);              in = fi.getChannel();//得到对应的文件通道              out = fo.getChannel();//得到对应的文件通道              in.transferTo(0, in.size(), out);//连接两个通道，并且从in通道读取，然后写入out通道          } catch (IOException e) {              e.printStackTrace();          } finally {              try {                  fi.close();                  in.close();                  fo.close();                  out.close();              } catch (IOException e) {                  e.printStackTrace();              }          }      }    /**     * 上传文件     * @param upFile 上传文件     * @param targetFile 目标文件     * @param b     * @return     */    public static boolean fileUpload(File upFile , File targetFile , byte[] b){                    InputStream is = null ;                    OutputStream os = null ;                    try{                             is =  new FileInputStream(upFile);                             os= new FileOutputStream(targetFile);                             int length = 0;                    while((length = is.read(b))>0){                             os.write(b, 0, length);                    }                    }catch(Exception e){                             e.printStackTrace();                             return false;                    }finally{                             try {                                      if(null != is){                                                is.close();                                        }if(null != os){                                                os.close();                                      }                             } catch (IOException e) {                                      e.printStackTrace();                             }                      }                    return true;          }    /**     * 删除文件     * @param f     * @return     */    public static boolean deleteFile(File f){             if (f.isFile())            f.delete();             return true;    }    /**     * 删除文件夹     * @param f     * @return     */    public static boolean deleteDir(File f){             if(f.isDirectory()){                       File[] files = f.listFiles();                       for(int i=0;i<files.length;i++){                                if(files[i].isDirectory()) deleteDir(files[i]);                                else deleteFile(files[i]);                       }             }             f.delete();             return true ;    }          /**     * 文件下载     * @param filePath 文件路径     * @param fileType 文件类型     * @param downName 下载文件名称     * @param response 响应     */    public static void downLoadFile(String filePath,String fileType ,String downName,HttpServletResponse response){                    OutputStream out = null;// 创建一个输出流对象                    String headerStr = downName;                    try{                             InputStream is=new FileInputStream(filePath);                             out = response.getOutputStream();//                  headerStr =new String( headerStr.getBytes("gb2312"), "ISO8859-1" );//headerString为中文时转码                             response.setHeader("Content-disposition", "attachment; filename="+ headerStr+"."+fileType);// filename是下载的xls的名，建议最好用英文                             response.setContentType("application/msexcel;charset=GB2312");// 设置类型                             response.setHeader("Pragma", "No-cache");// 设置头                             response.setHeader("Cache-Control", "no-cache");// 设置头                             response.setDateHeader("Expires", 0);// 设置日期头                             // 输入流 和 输出流                             int len = 0;                             byte[] b = new byte[1024];                             while ((len = is.read(b)) != -1) {                                       out.write(b, 0, len);                             }                             is.close();                             out.flush();                             out.close();                    } catch (Exception e) {                             e.printStackTrace();                    } finally {                             try {                                      if (out != null) {                                                out.close();                                      }                             } catch (IOException e) {                                      e.printStackTrace();                             }                    }    }                   }