1.判断路径是文件还是目录

File subDir=new File("c:\\mp3");if(subDir.isDirectory()){   // 是目录}File mp3=new File("c:\\mp3\\avemaria.mp3");                    if(mp3.isFile()){   // 是文件}

2.列出目录下的文件和子目录

File dir = new File(fromDir);String[] children = dir.list();for (int i=0; i

3.文件拷贝

public static void copyFile(File sourceFile, File targetFile) throws IOException {        BufferedInputStream inBuff = null;        BufferedOutputStream outBuff = null;        try {            // 新建文件输入流并对它进行缓冲            inBuff = new BufferedInputStream(new FileInputStream(sourceFile));            // 新建文件输出流并对它进行缓冲            outBuff = new BufferedOutputStream(new FileOutputStream(targetFile));            // 缓冲数组            byte[] b = new byte[1024 * 5];            int len;            while ((len = inBuff.read(b)) != -1) {                outBuff.write(b, 0, len);            }            // 刷新此缓冲的输出流            outBuff.flush();        } finally {            // 关闭流            if (inBuff != null)                inBuff.close();            if (outBuff != null)                outBuff.close();        }    }

2016年8月26日23:39:27改版

/**     * 将文件上传到服务器，返回在服务器的路径文件名     * @param in     * @param filename     * @return     * @throws Exception     */    public String upload2Server(InputStream in, String filename) throws Exception {        BufferedInputStream inBuff = null;        BufferedOutputStream outBuff = null;        try {            // 新建文件输入流并对它进行缓冲            inBuff = new BufferedInputStream(in);            // 新建文件输出流并对它进行缓冲            String filePathname=uploadPath+getTimePrefix()+filename;            outBuff = new BufferedOutputStream(new FileOutputStream(new File(filePathname)));            // 缓冲数组            byte[] b = new byte[1024 * 5];            int len;            while ((len = inBuff.read(b)) != -1) {                outBuff.write(b, 0, len);            }            // 刷新此缓冲的输出流            outBuff.flush();                        return filePathname;        } catch(Exception ex){            logger.error(ex);            throw ex;        }        finally {            // 关闭流            if (inBuff != null)                inBuff.close();            if (outBuff != null)                outBuff.close();        }    }

 

 

4.取得操作系统的临时目录

String folder=System.getProperty("java.io.tmpdir");