[JAVA]client端使用socket向server端上传文件为何失败？

Question

1.问题描述：

在写一个client端通过socket向本地Server端上传demo代码时，将socket的InputStream封装在BufferedInputStream中就无法实现。

2.代码实现

# Server端代码

ServerSocket server = new ServerSocket(3333);
while(true) {
    final Socket socket = server.accept();
    new Thread() {
        public void run() {
            try {
                InputStream is = socket.getInputStream();
                OutputStream os = socket.getOutputStream();

                FileOutputStream fos = new FileOutputStream("lib/test2");
                int len = 0;
                byte[] arr = new byte[8*1024];
                while((len = is.read(arr)) != -1) {
                    fos.write(arr, 0, len);
                }
                fos.close();
                socket.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }.start();
}

错误的client端代码

FileInputStream fis = new FileInputStream("test");
Socket socket = new Socket("127.0.0.1",3333);
InputStream is = socket.getInputStream();
OutputStream os = socket.getOutputStream();

BufferedOutputStream bos = new BufferedOutputStream(os);
BufferedInputStream bis = new BufferedInputStream(fis);
int len;
while((len = bis.read()) != -1) {
    bos.write(len);
}
socket.close();

可成功client端代码（不对Socekt的OutputStream进行封装即可上传成功）

FileInputStream fis = new FileInputStream("test");
Socket socket = new Socket("127.0.0.1",3333);
InputStream is = socket.getInputStream();
OutputStream os = socket.getOutputStream();

// BufferedOutputStream bos = new BufferedOutputStream(os);
BufferedInputStream bis = new BufferedInputStream(fis);
int len;
while((len = bis.read()) != -1) {
    os.write(len);
}
socket.close();

3.问题现象

在执行错误的client端代码时，client与server均处于等待状态

还大神赐教原因是什么？是不能对Socket中的InputStream和OutputStream进行封装么？

Answer 1

BufferedOutputStream 没有调用flush()吧？这样数据都在缓存中，都没输出，所以会在等待状态