场景：JDK8 将上传的文件，保存到服务器
Java读写文件操作：
MultipartFile file
InputStream inputStream = file.getInputStream();
private void saveOldFile(String uid,String fileName,InputStream inputStream){
String filePath = getFilePath() + "/" + uid +fileName;
BufferedReader reader = null;
BufferedWriter writer = null;
try {
File file = new File(filePath);
reader = new BufferedReader(new InputStreamReader(inputStream));
writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file)));
String lineText = null;
while ((lineText = reader.readLine()) != null){
writer.write(lineText+FILE_CONTENT_SPLIT_MARK);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
writer.close();
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}