Java 无法从套接字读取
大家好! 我正在尝试使用套接字创建我的第一个Java应用程序。我从插座上读东西有困难。 以下是服务器线程的源代码:Java 无法从套接字读取,java,sockets,Java,Sockets,大家好! 我正在尝试使用套接字创建我的第一个Java应用程序。我从插座上读东西有困难。 以下是服务器线程的源代码: public class ServerThread extends Thread{ private final int SERVER_PORT = 444; private ServerSocket serv; public ServerThread(){ try { serv = new ServerSocket(SERVER_PORT); }
public class ServerThread extends Thread{
private final int SERVER_PORT = 444;
private ServerSocket serv;
public ServerThread(){
try {
serv = new ServerSocket(SERVER_PORT);
} catch (IOException ex) {
Logger.getLogger(ServerThread.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public void run(){
while(true){
try {
Socket client = serv.accept();
client.setSoTimeout(0);
client.setTcpNoDelay(true);
client.setSendBufferSize(65536);
if(client.isConnected()){
new Thread(new MsgSrv(client)).start();
System.out.println("Client connected");
}
} catch (IOException ex) {
Logger.getLogger(ServerThread.class.getName()).log(Level.SEVERE, null, ex);
}
}
} }
下面是一个处理客户端连接的类:
public class MsgSrv extends Thread{
private BufferedWriter out;
private BufferedReader in;
private boolean isFinished = false;
private String buff;
private Socket sock;
public MsgSrv(Socket sc){
try {
sock = sc;
in = new BufferedReader(new InputStreamReader(sc.getInputStream()));
out = new BufferedWriter(new OutputStreamWriter(sc.getOutputStream()));
} catch (IOException ex) {
Logger.getLogger(MsgSrv.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void run(){
while(!isFinished){
try {
buff=in.readLine();
System.out.println(buff);
out.write("Hello");
} catch (IOException ex) {
Logger.getLogger(MsgSrv.class.getName()).log(Level.SEVERE, null, ex);
isFinished=true;
}
}
}}
客户端应用程序向服务器发送一个字符串,并尝试读取答案。但什么也没发生。in.readLine不返回任何内容,并永远等待服务器的答复。你能帮我解决一个问题吗?
为了读取数据,我已经使用了DataInputStream、BufferedReader类。
客户端应用程序的源:
public class JavaApplication4 {
/**
* @param args the command line arguments
*/
public static Socket connectSock;
public static PrintWriter out;
public static DataInputStream in;
public static void main(String[] args) {
try {
connectSock = new Socket("127.0.0.1", 444);
if(connectSock.isConnected()){
in = new DataInputStream(connectSock.getInputStream());
out = new PrintWriter(connectSock.getOutputStream(), true);
out.println("!hello!");
out.flush();
String s;
while(true){
s = in.readUTF();
System.out.println(s);
}
}else
{
System.out.println("bad socket");
System.exit(0);
}
} catch (UnknownHostException ex) {
Logger.getLogger(JavaApplication4.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(JavaApplication4.class.getName()).log(Level.SEVERE, null, ex);
}
}}
就像使用PrintWriter对象发送字符串一样,使用Scanner对象读取字符串。像这样
input = server.getInputStream();
Scanner scanner = new Scanner(input);
while (scanner.hasNextLine()) {
s = (String) scanner.nextLine();
}
编辑:
如果像这样更改客户端,并确保在使用scanner.nextLine时在字符串末尾有一个换行符\n
你确定有联系吗?是的,我确定。因为服务器从客户端接收字符串。请使用服务器上的PrintWriter和Scanner,但仍然没有任何内容。顺便说一句如果我通过telnet连接到服务器,一切正常。服务器回答我。断开连接的测试都是毫无意义的。在这些点上不可能不连接套接字。断开连接的方法没有问题。服务器从客户端接收字符串并将其打印到控制台。但是客户端无法从服务器接收字符串。我的评论是评论,不是回答。在这些地方调用该方法仍然毫无意义。不要写无意义的代码。这只是混淆了问题。
if(connectSock.isConnected()){
Scanner scanner = new Scanner(connectSock.getInputStream());
out = new PrintWriter(connectSock.getOutputStream(), true);
out.println("!hello!");
out.flush();
String s;
while (scanner.hasNextLine()) {
s = (String) scanner.nextLine();
}
}else
{