所以我有两个应用程序，一个是用Qt5用C ++编写的，另一个是用Java编写的。 C ++应用程序充当客户端，该客户端连接到Java应用程序中的ServerSocket对象，然后该对象实例化连接中的套接字。然后，当我尝试将字符串发送到服务器时，要么要么重复发送字符串（例如20000次），要么服务器根本什么也没收到。
QString s = " This is a test string that will be sent to the server upon connection\n";
QTcpSocket *sock = new QTcpSocket;
sock->connectToHost(QHostAddress::LocalHost, 5000, QIODevice::ReadWrite);
sock->waitForConnected(5000);
QTextStream out(sock);
while(!sock->waitForBytesWritten(3000)) {
out << s << endl;
}
在上面的代码不会产生任何结果的情况下，以下代码会产生分段的字符串以及服务器重复接收到的字符串：
QString s = " This is a test string that will be sent to the server upon connection\n";
QTcpSocket *sock = new QTcpSocket;
sock->connectToHost(QHostAddress::LocalHost, 5000, QIODevice::ReadWrite);
sock->waitForConnected(5000);
QTextStream out(sock);
do {
out << s << endl;
} while(!sock->waitForBytesWritten(3000) | 1);
服务器是一个像这样的简单Java程序：
ServerSocket ss = new ServerSocket(5000);
Socket s = ss.accept();
DataInputStream in = new DataInputStream(s.getInputStream());
while (true){
String tmp = in.readUTF();
System.out.println(tmp);
if (tmp.contains(" ")){
break;
}
我希望输出是一个简单的This is a test string that will be sent to the server upon connection；但是，结果要么是一无所有，要么是以下几句话：
his is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
This is a test string that will be sent to the server upon connection
您对我如何解决此问题有任何想法吗？
答案 0 :(得分：0)
因此解决方案是将数据读取到SELECT UnitId, AVG(Rating)
FROM MyTable
GROUP BY UnitId
WHERE AVG(Rating) < 4 -- Bad: WHERE is for the raw values, before they're aggregated
中，然后使用字符串构造函数将其转换为这样的字符串：
byte[]我不知道为什么，但这是我得出的解决方案。尽管进行了较小的更改，但客户端几乎保持不变：
ServerSocket ss = new ServerSocket(5000);
Socket s = ss.accept();
DataInputStream in = new DataInputStream(s.getInputStream());
byte[] b = new byte[1024];
in.read(b);
String tmp = new String(b, "UTF8");
System.out.println(b);
System.out.println(tmp);
答案 1 :(得分：0)
（1）waitForBytesWritten在Windows上可能会失败-最好使用信号bytesWritten()
（2）循环
while(!sock->waitForBytesWritten(3000) | 1);
对我来说似乎像一个无休止的循环，与waitForBytesWritten的返回代码无关
（3）在您的程序上下文中waitForBytesWritten的想法是什么？它可能在写入流的第一个字节之后返回！
（4）的想法是
if (tmp.contains(" ")){
break;
对我来说，这似乎在收到任何空白后可能会中断-例如“此”之后的第一个空白。根据readUTF的交付量，它也可能会中断几行（我不是Java专家）。
（5）readUTF期望使用修改后的UTF8格式的字符串，但是Qt不会发送修改后的UTF8格式的字符串（带有长度的前导16位整数）。因此，Java会将前两个字符（'Th'）解释为长度，然后彩票便会开始-根据这两个字符，解码将返回看似随意的结果。