![](/img/trans.png)
[英]File Transfer from Server to Client using java sockets. Error on Server side and File transferred to client is empty
[英]How can I transfer files from Server-Side to Client using Sockets?
我在哪里開始執行此任務時遇到了麻煩,我想要一些示例或輸入內容,說明如何設置服務器/客戶端組件以接收和發送數據,包括讓客戶端下載圖像。
這是我的客戶端代碼:
package V3;
import java.io.*;
import java.net.*;
public class Version3Client {
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();
}
}
這是我的服務器端代碼:
package V3;
import java.net.*;
import java.io.*;
public class Version3Server {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
boolean listening = true;
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.err.println("Could not listen on port: 4444.");
System.exit(-1);
}
while (listening)
new Version3ServerThread(serverSocket.accept()).start();
serverSocket.close();
Socket clientSocket = null;
try {
clientSocket = serverSocket.accept();
} 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;
Version3Protocol kkp = new Version3Protocol();
outputLine = kkp.processInput(null);
out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
outputLine = kkp.processInput(inputLine);
out.println(outputLine);
if (outputLine.equals("Bye."))
break;
}
out.close();
in.close();
clientSocket.close();
serverSocket.close();
}
}
添加了線程類以進一步規范:
package V3;
import java.net.*;
import java.io.*;
import java.io.FileWriter;
public class Version3ServerThread extends Thread {
private Socket socket = null;
public Version3ServerThread(Socket socket) {
super("Version3ServerThread");
this.socket = socket;
}
public void run() {
try {
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(
socket.getInputStream()));
String inputLine, outputLine;
Version3Protocol kkp = new Version3Protocol();
outputLine = kkp.processInput(null);
out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
outputLine = kkp.processInput(inputLine);
out.println(outputLine);
if (outputLine.equals("Bye"))
break;
if(kkp.getInteraction()){
Logging.writeToFile(socket.getInetAddress());
}
}
out.close();
in.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
到目前為止的代碼,沒有文件傳輸能力的客戶機/服務器通信,對我來說還不錯。 我想編譯以查找任何錯誤,但您沒有包括Version3Protocol和Logging。 如果可以編譯,則下一步是使用FileInputStream打開要在服務器上傳輸的文件,並使用FileOutputStream在客戶端上寫入新文件:
http://download.oracle.com/javase/1.4.2/docs/api/java/io/FileInputStream.html http://download.oracle.com/javase/1.4.2/docs/api/java/io /FileOutputStream.html
然后,您可以將文件讀入緩沖區,使用套接字傳輸它,在客戶端接收它,然后將緩沖區內容復制到FileOutputStream中。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.