锁定文件以在android中编写 [英] Lock file for writing in android

问题描述

我正在将一些数据存储在SD卡上的文件中，并从不同的线程读取同一文件.为了避免读写的竞争状况，我想在两种情况下都将文件锁定(读写)

I am storing some data on a file on SD card and reading the same file from different thread . To avoid race condition of reading and writing I want to lock the file in both the scenario (Reading and writing)

我有两个选择 1)我可以使用同步来做到这一点 2)我可以使用文件锁定

I have two options in my mind 1) I can do this using Synchronization 2) I can do this using File Lock

我应该选择哪个，为什么?哪一个内存效率更高?

Which one should I choose and why ? Which one is more memory efficient?

我知道同步方式，但是我不知道如何使用文件锁，所以有人可以告诉我使用文件锁的代码吗?

I know Synchronization way but I don't know how to use File Lock so can any one tell me the code for using file lock ?

我尝试了文件锁定，但是在android中不起作用，请查看代码. 感谢您的帮助

I tried with file lock but it is not working in android , please have a look at the code. Any help is appreciated

File syncDatafile = new File(file, "sync.txt");
                FileInputStream fileInputStream = new FileInputStream(syncDatafile);
                java.nio.channels.FileLock lock = fileInputStream.getChannel().lock();
                try{
                    FileWriter writer = new FileWriter(syncDatafile, true);
                    writer.write(data);
                    writer.flush();
                    writer.close();
                }catch(Exception ex){
                    ex.printStackTrace();
                }finally{
                    lock.release();
                    fileInputStream.close();
                }

推荐答案

对不起，这是我的错误，我使用了FileInputStream来读取文件.很抱歉，现在已解决

I am sorry guys it was my mistake I was using FileInputStream which is used for reading a file . I am so sorry, now it's fixed

File syncDatafile = new File(file, "sync.txt");
                FileOutputStream fileoutputStream = new FileOutputStream (syncDatafile);
                java.nio.channels.FileLock lock = fileInputStream.getChannel().lock();
                try{
                    FileWriter writer = new FileWriter(syncDatafile, true);
                    writer.write(data);
                    writer.flush();
                    writer.close();
                }catch(Exception ex){
                    ex.printStackTrace();
                }finally{
                    lock.release();
                    fileInputStream.close();
                }

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