我正在尝试通过Socket通信将数据从我的服务器发送到我的客户端，并且我在接收端收到错误。
以下是我的代码段 -
服务器 - 此类称为CLIENTConnection，负责从服务器到客户端的所有连接
import java.net.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.*;
public class CLIENTConnection implements Runnable {
private Socket clientSocket;
private BufferedReader in = null;
public CLIENTConnection(Socket client) {
this.clientSocket = client;
}
@Override
public void run() {
try {
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
String clientSelection=in.readLine();
while (clientSelection != null) {
switch (clientSelection) {
case "1":
receiveFile();
break;
case "2":
System.out.println("inside case 2");
String outGoingFileName = in.readLine();
System.out.println(outGoingFileName);
while (outGoingFileName != null) {
System.out.println("Inside while loop");
sendFile(outGoingFileName);
}
System.out.println("Out of while");
break;
case "3":
receiveFile();
break;
default:
System.out.println("Incorrect command received.");
break;
}
in.close();
break;
}
} catch (IOException ex) {
Logger.getLogger(CLIENTConnection.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void receiveFile() {
try {
int bytesRead;
DataInputStream clientData = new DataInputStream(clientSocket.getInputStream());
String filename = clientData.readUTF();
System.out.println(filename+" is received on server side");
OutputStream output = new FileOutputStream(("C://Users/Personal/workspace/ClientServer/src/dir/"+filename));
long size = clientData.readLong();
byte[] buffer = new byte[1024];
while (size > 0 && (bytesRead = clientData.read(buffer, 0, (int) Math.min(buffer.length, size))) != -1) {
output.write(buffer, 0, bytesRead);
size -= bytesRead;
}
output.close();
clientData.close();
System.out.println("File "+filename+" received from client.");
} catch (IOException ex) {
System.err.println("Client error. Connection closed.");
}
}
public void sendFile(String fileName) {
try {
//handle file read
File myFile = new File("C://Users/Personal/workspace/ClientServer/src/dir/"+fileName);
byte[] mybytearray = new byte[(int) myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
//bis.read(mybytearray, 0, mybytearray.length);
DataInputStream dis = new DataInputStream(bis);
dis.readFully(mybytearray, 0, mybytearray.length);
//handle file send over socket
OutputStream os = clientSocket.getOutputStream();
//Sending file name and file size to the server
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF(myFile.getName());
dos.writeLong(mybytearray.length);
dos.write(mybytearray, 0, mybytearray.length);
dos.flush();
System.out.println("File "+fileName+" sent to client.");
} catch (Exception e) {
System.err.println("File does not exist!");
}
}
}
客户端（接收文件）
public class FileClient {
private static Socket sock;
private static String fileName;
private static BufferedReader stdin;
private static PrintStream os;
public static void main(String[] args) throws IOException, ClassNotFoundException {
ObjectInputStream inFromServer;
try
{
sock = new Socket("localhost", 7777);
stdin = new BufferedReader(new InputStreamReader(System.in));
} catch (Exception e) {
System.err.println("Cannot connect to the server, try again later.");
System.exit(1);
}
inFromServer= new ObjectInputStream(sock.getInputStream());
os = new PrintStream(sock.getOutputStream());
try {
switch (Integer.parseInt(selectAction())) {
case 1:
os.println("1");
sendFile();
break;
case 2:
os.println("2");
System.err.print("Enter file name: ");
fileName = stdin.readLine();
os.println(fileName);
receiveFile(fileName);
break;
case 3:
os.println("3");
Synchronise();
}
} catch (Exception e) {
System.err.println("not valid input");
}
sock.close();
}
private static void Synchronise()
{
HashMap<String, Calendar> ClientFileList=getTimeStamp("C://Users/Personal/workspace/ClientServer/Client/");//getting the filename and timestamp of all the files present in client folder.
/*System.out.println("Client File List : \n");
for(String s : ClientFileList.keySet())
System.out.println(s);*/
HashMap<String, Calendar> ServerFileList=getTimeStamp("C://Users/Personal/workspace/ClientServer/src/dir/");//(HashMap<String, Calendar>) inFromServer.readObject();
/*System.out.println("\nServer File List : \n");
for(String s : ClientFileList.keySet())
System.out.println(s);*/
System.out.println("File comparision output");
compareTimestamp(ClientFileList,ServerFileList);
}
private static void compareTimestamp(HashMap<String, Calendar> ClientFileList, HashMap<String, Calendar> serverFileList)
{
LinkedList<String> fileToUpload=new LinkedList<String>();
LinkedList<String> fileToDownload=new LinkedList<String>();
LinkedList<String> fileToDeleteFromClient=new LinkedList<String>();
LinkedList<String> fileToDeleteFromServer=new LinkedList<String>();
Calendar clientCalender = null,serverCalendar=null;
for (String filename : serverFileList.keySet())
{
serverCalendar=serverFileList.get(filename);
if(ClientFileList.containsKey(filename))
{
clientCalender=ClientFileList.get(filename);
if(clientCalender.before(serverCalendar))
{
fileToDownload.add(filename);
}
else
{
fileToUpload.add(filename);
}
}
else
{
fileToDeleteFromClient.add(filename);
}
}
for (String filename : ClientFileList.keySet())
{
clientCalender=ClientFileList.get(filename);
if(!serverFileList.containsKey(filename))
{
fileToDeleteFromServer.add(filename);
}
}
System.out.println("Files to download to client: "+fileToDownload);
System.out.println("Files to upload to Server: "+fileToUpload);
System.out.println("Files to delete from client: "+fileToDeleteFromClient);
System.out.println("Files to delete from Server: "+fileToDeleteFromServer);
sendFile(fileToDeleteFromServer);
}
private static HashMap<String, Calendar> getTimeStamp(String location)
{
HashMap<String,Calendar> fileList = new HashMap<String,Calendar>();
File dir = new File(location);
File[] files = dir.listFiles();
if (files.length == 0)
{
System.out.println("No file found");
//System.exit(1);
}
else
{
for (int i = 0; i < files.length; i++)
{
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(files[i].lastModified());
fileList.put(files[i].getName(), calendar);
}
}
return fileList;
}
public static String selectAction() throws IOException
{
System.out.println("1. Send file.");
System.out.println("2. Recieve file.");
System.out.println("3. Synchronize");
System.out.print("\nMake selection: ");
return stdin.readLine();
}
public static void sendFile()
{
try {
System.err.print("Enter file name: ");
fileName = stdin.readLine();
File myFile = new File("C:/Users/Personal/workspace/ClientServer/Client/"+fileName);
byte[] mybytearray = new byte[(int) myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
//bis.read(mybytearray, 0, mybytearray.length);
DataInputStream dis = new DataInputStream(bis);
dis.readFully(mybytearray, 0, mybytearray.length);
OutputStream os = sock.getOutputStream();
//Sending file name and file size to the server
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF(myFile.getName());
dos.writeLong(mybytearray.length);
dos.write(mybytearray, 0, mybytearray.length);
dos.flush();
dis.close();
System.out.println("File "+fileName+" sent to Server.");
}
catch (Exception e)
{
System.err.println("File does not exist!");
}
}
//receive a list of file to upload to server from client.
static void sendFile(LinkedList<String> fileList)
{
for(String file: fileList)
sendFile(file);
}
public static void sendFile(String filename) {
File file = new File("C:/Users/Personal/workspace/ClientServer/Client/"+filename);
byte[] mybytearray = new byte[(int) file.length()];
FileInputStream fis;
try
{
fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
//bis.read(mybytearray, 0, mybytearray.length);
DataInputStream dis = new DataInputStream(bis);
dis.readFully(mybytearray, 0, mybytearray.length);
OutputStream os = sock.getOutputStream();
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF(file.getName());
dos.writeLong(mybytearray.length);
dos.write(mybytearray, 0, mybytearray.length);
dos.flush();
dis.close();
System.out.println("File "+filename+" sent to Server.");
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void receiveFile(String fileName) {
try {
int bytesRead;
InputStream in = sock.getInputStream();
DataInputStream clientData = new DataInputStream(in);
fileName = clientData.readUTF();
OutputStream output = new FileOutputStream(("received_from_server_"));
long size = clientData.readLong();
byte[] buffer = new byte[1024];
while (size > 0 && (bytesRead = clientData.read(buffer, 0, (int) Math.min(buffer.length, size))) != -1) {
output.write(buffer, 0, bytesRead);
size -= bytesRead;
}
output.close();
in.close();
System.out.println("File "+fileName+" received from Server.");
} catch (IOException ex) {
Logger.getLogger(CLIENTConnection.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
显示错误
filename = clientData.readUTF();
如果有任何可能的解决方案，请告诉我。
答案 0 :(得分：0)
DataInputStream使用此异常来表示流的结束。因此，异常可能不是错误，只是意味着已经发送了数据。
在阅读之前，您必须检查您是否已收到某些内容，然后阅读。
检查this：
This exception is mainly used by data input streams to signal end of stream. Note that many other input operations return a special value on end of stream rather than throwing an exception.
答案 1 :(得分：0)
你收到档案了吗？
public static void receiveFile(String fileName) {
boolean recieving = true; //new
while(recieving){ //new
try {
int bytesRead;
InputStream in = sock.getInputStream();
DataInputStream clientData = new DataInputStream(in);
fileName = clientData.readUTF();
OutputStream output = new FileOutputStream(("received_from_server_"));
long size = clientData.readLong();
byte[] buffer = new byte[1024];
while (size > 0 && (bytesRead = clientData.read(buffer, 0, (int) Math.min(buffer.length, size))) != -1) {
output.write(buffer, 0, bytesRead);
size -= bytesRead;
}
output.close();
in.close();
System.out.println("File "+fileName+" received from Server.");
} catch (EOFException e){ // new
Logger.getLogger(CLIENTConnection.class.getName()).log(Level.SEVERE, null, ex);
recieving = false;
} catch (IOException ex) {
Logger.getLogger(CLIENTConnection.class.getName()).log(Level.SEVERE, null, ex);
}
} //new
}