Java套接字不';不要等待接收字节
我用java开发了一个套接字,如下所示:Java套接字不';不要等待接收字节,java,sockets,Java,Sockets,我用java开发了一个套接字,如下所示: serverSocket = new ServerSocket(port); System.out.println("Listening in port " + port + " ..."); while (true) { socket = serverSocket.accept(); System.out.println("Connection has been created."); handle(socket); }
serverSocket = new ServerSocket(port);
System.out.println("Listening in port " + port + " ...");
while (true) {
socket = serverSocket.accept();
System.out.println("Connection has been created.");
handle(socket);
}
class MyClass {
private Socket socket;
private InputStream is;
private PrintWriter out;
private OutputStream ds;
public MyClass(Socket socket, InputStream is) {
this.socket = socket;
this.is = is;
initializeOutputStream(socket);
}
private void initializeOutputStream(Socket socket) {
try {
ds = socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
}
public void start() {
while (true) {
try {
int dataLength = 10;
byte[] dataBuffer = new byte[dataLength];
is.read(dataBuffer, 0, dataLength);
// Read and Print cmd.
System.out.println("data:" + DataLayer.byteToString(dataBuffer));
} catch (IOException e) {
e.printStackTrace();
try {
ds.close();
System.out.println("ds closed.");
is.close();
System.out.println("is closed.");
socket.close();
System.out.println("socket closed.");
break;
} catch (IOException e1) {
e1.printStackTrace();
}
e.printStackTrace();
}
}
}
}
而句柄
方法是:
private static void handle(final Socket socket) throws IOException {
new Thread(new Runnable() {
@Override
public void run() {
try {
InputStream is = socket.getInputStream();
MyClass elevator = new MyClass(socket, is);
elevator.start();
} catch (IOException io) {
io.printStackTrace();
} finally {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}).start();
}
MyClass是这样的:
serverSocket = new ServerSocket(port);
System.out.println("Listening in port " + port + " ...");
while (true) {
socket = serverSocket.accept();
System.out.println("Connection has been created.");
handle(socket);
}
class MyClass {
private Socket socket;
private InputStream is;
private PrintWriter out;
private OutputStream ds;
public MyClass(Socket socket, InputStream is) {
this.socket = socket;
this.is = is;
initializeOutputStream(socket);
}
private void initializeOutputStream(Socket socket) {
try {
ds = socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
}
public void start() {
while (true) {
try {
int dataLength = 10;
byte[] dataBuffer = new byte[dataLength];
is.read(dataBuffer, 0, dataLength);
// Read and Print cmd.
System.out.println("data:" + DataLayer.byteToString(dataBuffer));
} catch (IOException e) {
e.printStackTrace();
try {
ds.close();
System.out.println("ds closed.");
is.close();
System.out.println("is closed.");
socket.close();
System.out.println("socket closed.");
break;
} catch (IOException e1) {
e1.printStackTrace();
}
e.printStackTrace();
}
}
}
}
当客户端发送数据时,它工作正常,但当客户端不发送数据时,它会打印:
data:0
data:0
data:0
...
它不会停止
您能告诉我如何解决这个问题吗?您描述的情况发生在客户端关闭连接时(即,套接字在最后关闭/流),而不是在客户端不发送任何内容时(如果客户端空闲但仍然连接,服务器不打印任何内容) 这是因为
InputStream
类的read
方法在流/连接关闭时不会抛出异常,而只是返回值-1
,因此在您的实现中,while循环继续无限运行
因此,此问题的快速解决方法是将读取流的行替换为以下两行:
int endOfStream=is.read(dataBuffer, 0, dataLength);
if(endOfStream==-1) break;
基本上,通过这种方式,您可以检查流是否已关闭:如果是这种情况,请中断while循环
另一个解决方案是声明并初始化变量intendofstream=0编码>在while循环之前,并通过以下方式更改while循环条件:
int endOfStream = 0; //init to 0 to enter a first time in the loop
while (endOfStream != -1) { //new loop condition
try {
int dataLength = 10;
byte[] dataBuffer = new byte[dataLength];
endOfStream = is.read(dataBuffer, 0, dataLength); //store the return of read
if (endOfStream != -1) { //check if we are not at the end of the stream
// Read and Print cmd.
System.out.println("data:" + dataBuffer[0]);
}
//... the rest of your code ...
代码中的另一个问题是我猜是一个bug,但我不确定,因为否则您将无法运行代码(但我不能说,因为您复制的代码不完整)。错误是在调用start方法MyClass.start()时出现的代码>:由于此方法不是静态的,因此必须在您之前实例化该行的类MyClass
的对象上调用它,即以以下方式调用此方法:lifter.start()代码>
我希望这能对您有所帮助。什么是。read
返回?“endOfStream”是一个奇怪的变量名称,它包含读取计数或流结束指示符值。它不是布尔值。Thnx Enne,对不起,实际上它是电梯。开始();如果(is.read(dataBuffer,0,dataLength)=-1)中断,我尝试编写代码;现在我来检查它是否工作正常。@EJP您是对的,但这只是为了让OP超级清晰
int something = is.read(dataBuffer, 0, dataLength);
if(something ==-1)
break;
else
System.out.println("data:" + DataLayer.byteToString(dataBuffer));