有没有办法在到达文件末尾时阻止读取 util 有新数据写入 java 中的文件

Question

I have 2 java processes, process A writes data to file, process B reads data from file. Sometimes process A is not running, process B needs to read existing data from file,so I cannot use socket instead of file.

The problem is, when B reach to end of file, read function returns immediately,if I retry without sleep() , CPU usage is 100% even if there is no new data. If I try with sleep() , response time and performance is not good.

Is there any way to block read when reached end of file until there is new data written to file, as if I was using socket?

Answer 1

Try using WatchService API of java.nio package. In this, you can create watcher for any modifications in the directory. There will different events for different modifications based on which you can trigger the read.