将文件从Python服务器发送到Java客户端

我试图通过TCP套接字将文件从Python服务器发送到Java客户端。 这是我到目前为止：

Java客户端（请注意，所有文件传输代码都在getFile（）方法中）：

public class Client1 { private Socket socket = null; private FileOutputStream fos = null; private DataInputStream din = null; private PrintStream pout = null; private Scanner scan = null; public Client1(InetAddress address, int port) throws IOException { System.out.println("Initializing Client"); socket = new Socket(address, port); scan = new Scanner(System.in); din = new DataInputStream(socket.getInputStream()); pout = new PrintStream(socket.getOutputStream()); } public void send(String msg) throws IOException { pout.print(msg); pout.flush(); } public void closeConnections() throws IOException { // Clean up when a connection is ended socket.close(); din.close(); pout.close(); scan.close(); } // Request a specific file from the server public void getFile(String filename) { System.out.println("Requested File: "+filename); try { File file = new File(filename); // Create new file if it does not exist // Then request the file from server if(!file.exists()){ file.createNewFile(); System.out.println("Created New File: "+filename); } fos = new FileOutputStream(file); send(filename); // Get content in bytes and write to a file int counter; byte[] buffer = new byte[8192]; while((counter = din.read(buffer, 0, buffer.length)) != -1) { fos.write(buffer, 0, counter); } } fos.flush(); fos.close(); } catch (IOException e) { e.printStackTrace(); } } } 

和Python服务器：

 import socket host = '127.0.0.1' port = 5555 # Create a socket with port and host bindings def setupServer(): s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print("Socket created") try: s.bind((host, port)) except socket.error as msg: print(msg) return s # Establish connection with a client def setupConnection(): s.listen(1) # Allows one connection at a time print("Waiting for client") conn, addr = s.accept() return conn # Send file over the network def sendFile(filename, s): f = open(filename, 'rb') line = f.read(1024) print("Beginning File Transfer") while line: s.send(line) line = f.read(1024) f.close() print("Transfer Complete") # Loop that sends & receives data def dataTransfer(conn, s, mode): while True: # Send a File over the network filename = conn.recv(1024) filename = filename.decode(encoding='utf-8') filename.strip() print("Requested File: ", filename) sendFile(filename, s) break conn.close() s = setupServer() while True: try: conn = setupConnection() dataTransfer(conn, s, "FILE") except: break 

我能够在服务器和客户端之间成功创建一个消息传递程序，它们将字符串传递给另一个。 但是，我无法通过网络传输文件。

似乎Python服务器正在通过字节发送，因此Java端似乎是问题所在。 特别是while循环： while((counter = din.read(buffer, 0, buffer.length)) != -1)一直给出-1的输出，因此文件的写入实际上从未发生过。

在此先感谢您的帮助！

Answer 1

对于其他人来说，这就是我最终如何运作的方式。

服务器：

 import socket import select server_addr = '127.0.0.1', 5555 # Create a socket with port and host bindings def setupServer(): s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print("Socket created") try: s.bind(server_addr) except socket.error as msg: print(msg) return s # Establish connection with a client def setupConnection(s): s.listen(5) # Allows five connections at a time print("Waiting for client") conn, addr = s.accept() return conn # Get input from user def GET(): reply = input("Reply: ") return reply def sendFile(filename, conn): f = open(filename, 'rb') line = f.read(1024) print("Beginning File Transfer") while line: conn.send(line) line = f.read(1024) f.close() print("Transfer Complete") # Loop that sends & receives data def dataTransfer(conn, s, mode): while True: # Send a File over the network if mode == "SEND": filename = conn.recv(1024) filename = filename.decode(encoding='utf-8') filename.strip() print("Requested File: ", filename) sendFile(filename, conn) # conn.send(bytes("DONE", 'utf-8')) break # Chat between client and server elif mode == "CHAT": # Receive Data print("Connected with: ", conn) data = conn.recv(1024) data = data.decode(encoding='utf-8') data.strip() print("Client: " + data) command = str(data) if command == "QUIT": print("Server disconnecting") s.close() break # Send reply reply = GET() conn.send(bytes(reply, 'utf-8')) conn.close() sock = setupServer() while True: try: connection = setupConnection(sock) dataTransfer(connection, sock, "CHAT") except: break 

客户：

 import java.net.*; import java.io.*; import java.util.Scanner; public class ClientConnect { private Socket socket = null; private FileOutputStream fos = null; private DataInputStream din = null; private PrintStream pout = null; private Scanner scan = null; public ClientConnect(InetAddress address, int port) throws IOException { System.out.println("Initializing Client"); socket = new Socket(address, port); scan = new Scanner(System.in); din = new DataInputStream(socket.getInputStream()); pout = new PrintStream(socket.getOutputStream()); } public void send(String msg) throws IOException { pout.print(msg); pout.flush(); } public String recv() throws IOException { byte[] bytes = new byte[1024]; din.read(bytes); String reply = new String(bytes, "UTF-8"); System.out.println("Inside recv(): "); return reply; } public void closeConnections() throws IOException { // Clean up when a connection is ended socket.close(); din.close(); pout.close(); scan.close(); } public void chat() throws IOException { String response = "s"; System.out.println("Initiating Chat Sequence"); while(!response.equals("QUIT")){ System.out.print("Client: "); String message = scan.nextLine(); send(message); if(message.equals("QUIT")) break; response = recv(); System.out.println("Server: " + response); } closeConnections(); } // Request a specific file from the server public void getFile(String filename) { System.out.println("Requested File: "+filename); try { File file = new File(filename); // Create new file if it does not exist // Then request the file from server if(!file.exists()){ file.createNewFile(); System.out.println("Created New File: "+filename); } fos = new FileOutputStream(file); send(filename); // Get content in bytes and write to a file byte[] buffer = new byte[8192]; for(int counter=0; (counter = din.read(buffer, 0, buffer.length)) >= 0;) { fos.write(buffer, 0, counter); } fos.flush(); fos.close(); } catch (IOException e) { e.printStackTrace(); } } }