是否可以使用NIO处理进程的标准输出?我已经使用java.io实现了它,但这是为了更好地了解NIO并探索性能提升的可能性而进行的练习。
基本上,我想尽可能快地将大量文本从stdout流式传输到缓冲区中,而不会阻塞,然后稍后处理该缓冲区的内容。问题是,我似乎无法找到正确的方法来使用NIO实现。目前我的进展如下:
ProcessBuilder pb = new ProcessBuilder( ... );
Process p = pb.start();
stdout = new StreamConsumer(p.getInputStream());
new Thread(stdout).start();
// other stuff omitted for brevity
StreamConsumer类如下所示:
class StreamConsumer implements Runnable
{
private InputStream is;
public StreamConsumer(InputStream is)
{
this.is = is;
}
public void run()
{
try
{
ReadableByteChannel source = Channels.newChannel(is);
// Is it possible get a channel to a ByteBuffer
// or MappedByteBuffer here?
WritableByteChannel destination = ??;
ByteBuffer buffer = ByteBuffer.allocateDirect(128 * 1024);
while (source.read(buffer) != -1)
{
buffer.flip();
while (buffer.hasRemaining())
{
destination.write(buffer);
}
buffer.clear();
}
source.close();
destination.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}