file文件与base64字符串的相互转换

/**
* 文件转base64字符串
* @param file
* @return
*/
public static String fileToBase64(File file) {
String base64 = null;
InputStream in = null;
try {
in = new FileInputStream(file);
byte[] bytes = new byte[in.available()];
int length = in.read(bytes);
base64 = Base64.encodeToString(bytes, 0, length, Base64.DEFAULT);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return base64;
}

/**
* base64字符串转文件
* @param base64
* @return
*/
public static File base64ToFile(String base64) {
File file = null;
String fileName = "/Petssions/record/testFile.amr";
FileOutputStream out = null;
try {
// 解码，然后将字节转换为文件
file = new File(Environment.getExternalStorageDirectory(), fileName);
if (!file.exists())
file.createNewFile();
byte[] bytes = Base64.decode(base64, Base64.DEFAULT);// 将字符串转换为byte数组
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
byte[] buffer = new byte[1024];
out = new FileOutputStream(file);
int bytesum = 0;
int byteread = 0;
while ((byteread = in.read(buffer)) != -1) {
bytesum += byteread;
out.write(buffer, 0, byteread); // 文件写操作
}
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
try {
if (out!= null) {
out.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return file;
}