我正在關注網絡上的Java Trail。當我將它們複製/粘貼到Eclipse中時,用作示例的三個KnockKnock類(客戶機,服務器和協議)按預期工作。然而,我真正想要做的是消除協議類,只要讓服務器迴應客戶端,無論我輸入到控制檯。我嘗試修改服務器程序,主要是通過評論對協議類的引用,但不知何故,我最終打破了該程序。這個基本的客戶服務器程序爲什麼不傳遞數據?
我是如此的新,以至於我對於什麼是錯的一無所知,我在電子書和網站上搜索的答案越多,我就越困惑。我所發現的是,我幾乎不知道IO流如何真正起作用。我按順序粘貼了下面三個類:服務器,客戶端,協議。問題出在哪裏,以及爲什麼它是一個問題:
服務器:
import java.net.*;
import java.io.*;
public class KnockKnockServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.err.println("Could not listen on port: 4444.");
System.exit(1);
}
Socket clientSocket = null;
try {
clientSocket = serverSocket.accept();
System.out.println("Client Accepted");
} catch (IOException e) {
System.err.println("Accept failed.");
System.exit(1);
}
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(
clientSocket.getInputStream()));
String inputLine, outputLine;
//KnockKnockProtocol kkp = new KnockKnockProtocol();
//outputLine = kkp.processInput(null);
//out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
//outputLine = kkp.processInput(inputLine);
//out.println(outputLine);
out.println(inputLine);
if (inputLine.equals("Bye."))
break;
}
out.close();
in.close();
clientSocket.close();
serverSocket.close();
}
}
客戶:
import java.io.*;
import java.net.*;
public class KnockKnockClient {
public static void main(String[] args) throws IOException {
Socket kkSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try {
kkSocket = new Socket("localhost", 4444);
out = new PrintWriter(kkSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: taranis.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to: taranis.");
System.exit(1);
}
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
String fromServer;
String fromUser;
while ((fromServer = in.readLine()) != null) {
System.out.println("Server: " + fromServer);
if (fromServer.equals("Bye."))
break;
fromUser = stdIn.readLine();
if (fromUser != null) {
System.out.println("Client: " + fromUser);
out.println(fromUser);
}
}
out.close();
in.close();
stdIn.close();
kkSocket.close();
}
}
協議:
import java.net.*;
import java.io.*;
public class KnockKnockProtocol {
private static final int WAITING = 0;
private static final int SENTKNOCKKNOCK = 1;
private static final int SENTCLUE = 2;
private static final int ANOTHER = 3;
private static final int NUMJOKES = 5;
private int state = WAITING;
private int currentJoke = 0;
private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who", "Who" };
private String[] answers = { "Turnip the heat, it's cold in here!",
"I didn't know you could yodel!",
"Bless you!",
"Is there an owl in here?",
"Is there an echo in here?" };
public String processInput(String theInput) {
String theOutput = null;
if (state == WAITING) {
theOutput = "Knock! Knock!";
state = SENTKNOCKKNOCK;
} else if (state == SENTKNOCKKNOCK) {
if (theInput.equalsIgnoreCase("Who's there?")) {
theOutput = clues[currentJoke];
state = SENTCLUE;
} else {
theOutput = "You're supposed to say \"Who's there?\"! " +
"Try again. Knock! Knock!";
}
} else if (state == SENTCLUE) {
if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) {
theOutput = answers[currentJoke] + " Want another? (y/n)";
state = ANOTHER;
} else {
theOutput = "You're supposed to say \"" +
clues[currentJoke] +
" who?\"" +
"! Try again. Knock! Knock!";
state = SENTKNOCKKNOCK;
}
} else if (state == ANOTHER) {
if (theInput.equalsIgnoreCase("y")) {
theOutput = "Knock! Knock!";
if (currentJoke == (NUMJOKES - 1))
currentJoke = 0;
else
currentJoke++;
state = SENTKNOCKKNOCK;
} else {
theOutput = "Bye.";
state = WAITING;
}
}
return theOutput;
}
}
看這裏:http://stackoverflow.com/questions/15653074/a-simple-java-client-server- program?rq = 1 – KevinDTimm 2013-04-04 16:16:14