File与Base64相互转换

public static String file2Base64(File file) {
        if(file==null) {
            return null;
        }
        String base64 = null;
        FileInputStream fin = null;
        try {
            fin = new FileInputStream(file);
            byte[] buff = new byte[fin.available()];
            fin.read(buff);
            base64 = Base64.encode(buff);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fin != null) {
                try {
                    fin.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return base64;
    }

public static File base64ToFile(String base64) {
        if(base64==null||"".equals(base64)) {
            return null;
        }
        byte[] buff=Base64.decode(base64);
        File file=null;
        FileOutputStream fout=null;
        try {
            file = File.createTempFile("tmp", null);
            fout=new FileOutputStream(file);
            fout.write(buff);
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(fout!=null) {
                try {
                    fout.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return file;
    }