我正在通过套接字从客户端向服务器发送文件。多数民众赞成工作。但是一旦收到文件,服务器程序就不会收到任何进一步的消息。它的所有接收都是空的。 这是客户端 - 服务器代码。
客户端:
main(...){
Socket sock = new Socket("127.0.0.1", 12345);
File file = new File("file.txt");
byte[] mybytearray = new byte[(int) file.length()];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
bis.read(mybytearray, 0, mybytearray.length);
OutputStream os = sock.getOutputStream();
os.write(mybytearray, 0, mybytearray.length);
PrintWriter out = new PrintWriter(os, true);
out.println("next message");
//closing here all streams and socket
}
服务器:
main(...){
ServerSocket servsock = new ServerSocket(12345);
while (true) {
Socket sock = servsock.accept();
byte[] mybytearray = new byte[1024];
InputStream is = sock.getInputStream();
Scanner scan1 = new Scanner(is);
FileOutputStream fos = new FileOutputStream("myfile.txt");
BufferedOutputStream bos = new BufferedOutputStream(fos);
int bytesRead = is.read(mybytearray, 0, mybytearray.length);
bos.write(mybytearray, 0, bytesRead);
bos.close();
fos.close();
//Till here works fine, and file is successfully received.
//Below is the code to receive next message.
//Unfortunately it is not working
BufferedReader input = new BufferedReader(new InputStreamReader(is));
String line = input.readLine();
System.out.println(line); //prints null, Whats the reason?
}
}
答案 0 :(得分:1)
基本问题是你假设a)当你阅读时你的文件正好是1024字节长。 b)当您尝试阅读时,您可以一次性获取所有数据。即使你写了更多内容,最小值也是1个字节。
我建议你
答案 1 :(得分:1)
这是一个假设它是文件然后是一行文本的示例。在这两种情况下,我首先发送长度,以便它可以作为字节数组处理。
服务器:
ServerSocket servsock = new ServerSocket(12345);
while (true) {
Socket sock = servsock.accept();
try (DataInputStream dis = new DataInputStream(sock.getInputStream())) {
int len = dis.readInt();
byte[] mybytearray = new byte[len];
dis.readFully(mybytearray);
try (FileOutputStream fos = new FileOutputStream("myfile.txt")) {
fos.write(mybytearray);
}
len = dis.readInt();
mybytearray = new byte[len];
dis.readFully(mybytearray);
String line = new String(mybytearray);
System.out.println("line = " + line);
}
}
客户端:
Socket sock = new Socket("127.0.0.1", 12345);
File file = new File("file.txt");
byte[] mybytearray = new byte[(int) file.length()];
DataInputStream dis = new DataInputStream(new FileInputStream(file));
dis.readFully(mybytearray);
try(DataOutputStream os = new DataOutputStream(sock.getOutputStream())) {
os.writeInt(mybytearray.length);
os.write(mybytearray, 0, mybytearray.length);
String nextMessage = "next message\n";
byte message[] = nextMessage.getBytes();
os.writeInt(message.length);
os.write(message, 0, message.length);
}