继续收到此错误 ＆＃34; java.util.NoSuchElementException：找不到行错误java＆＃34; 并通过代码搜索了很多次，并且无法找到问题继承人我的文件可以有人帮忙吗？ 我目前正在做这个任务，并试图将它从无线程转移到线程，并在此过程中出现了这个错误!!
This is the Client class
package Client;
import core.Email;
import core.EmailServiceDetails;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Date;
import java.util.InputMismatchException;
import java.util.Scanner;
public class EmailClient {
public static void main(String[] args) {
try
{
// Step 1 (on consumer side) - Establish channel of communication
Socket dataSocket = new Socket("localhost", EmailServiceDetails.LISTENING_PORT);
// Step 3) Build output and input objects
OutputStream out = dataSocket.getOutputStream();
PrintWriter output = new PrintWriter(new OutputStreamWriter(out));
InputStream in = dataSocket.getInputStream();
Scanner input = new Scanner(new InputStreamReader(in));
Scanner keyboard = new Scanner(System.in);
String message = "";
while(!message.equals(EmailServiceDetails.END_SESSION))
{
displayMenu();
int choice = getNumber(keyboard);
String response = "";
if(choice >=0 && choice < 3)
{
switch (choice)
{
case 0:
message = EmailServiceDetails.END_SESSION;
// Send message
output.println(message);
output.flush();
response = input.nextLine();
if(response.equals(EmailServiceDetails.SESSION_TERMINATED))
{
System.out.println("Session ended.");
}
break;
case 1:
message = sendEmail(keyboard);
// Send message
output.println(message);
output.flush();
// Get response
response = input.nextLine();
if(response.equals(EmailServiceDetails.SUCCESSFUL_ADD))
{
System.out.println("Email sent successfully");
}
else if(response.equals(EmailServiceDetails.UNSUCCESSFUL_ADD))
{
System.out.println("Sorry, the email could not be sent at this time.");
}
break;
case 2:
message = viewUnread(keyboard);
// Send message
output.println(message);
output.flush();
// Get response
response = input.nextLine();
if(response.equals(EmailServiceDetails.NO_UNREAD))
{
System.out.println("No unread mails found for that account.");
}
else
{
ArrayList<Email> unreadMails = EmailServiceDetails.parseEmailList(response);
System.out.println("Unread Emails:");
for(Email e: unreadMails)
{
System.out.println(e);
}
}
break;
}
if(response.equals(EmailServiceDetails.UNRECOGNISED))
{
System.out.println("Sorry, that request cannot be recognised.");
}
}
else
{
System.out.println("Please select an option from the menu");
}
}
System.out.println("Thank you for using the Email system.");
dataSocket.close();
}catch(Exception e)
{
System.out.println("An error occurred: " + e.getMessage());
e.printStackTrace();
}
}
public static void displayMenu()
{
System.out.println("0) Exit");
System.out.println("1) Send an email");
System.out.println("2) View all unread mails");
}
public static int getNumber(Scanner keyboard)
{
boolean numberEntered = false;
int number = 0;
while(!numberEntered)
{
try{
number = keyboard.nextInt();
numberEntered = true;
}
catch(InputMismatchException e)
{
System.out.println("Please enter a number.");
keyboard.nextLine();
}
}
keyboard.nextLine();
return number;
}
public static String sendEmail(Scanner keyboard)
{
System.out.println("Please enter the sender of this email:");
String sender = keyboard.nextLine();
// Get recipient information
String anotherRecipient = "Y";
ArrayList<String> recipients = new ArrayList();
while(anotherRecipient.equalsIgnoreCase("Y"))
{
System.out.println("Enter the recipient's email address:");
String recipient = keyboard.nextLine();
recipients.add(recipient);
System.out.println("Would you like to add another recipient? ('Y' for yes and 'N' for no)");
anotherRecipient = keyboard.nextLine();
}
System.out.println("Please enter the email subject:");
String subject = keyboard.nextLine();
System.out.println("Please enter the message body:");
String body = keyboard.nextLine();
// Get attachment information
ArrayList<String> attachments = new ArrayList();
System.out.println("Would you like to enter an attachment ('Y' to add and 'N' to continue)");
String anotherAttachment = keyboard.nextLine();
while(anotherAttachment.equalsIgnoreCase("Y"))
{
System.out.println("Enter the attachment information:");
String attachment = keyboard.nextLine();
attachments.add(attachment);
System.out.println("Would you like to add another attachment? ('Y' for yes and 'N' to Continue)");
anotherAttachment = keyboard.nextLine();
}
long timestamp = new Date().getTime();
String response = null;
Email e = null;
if(attachments.size() > 0)
{
e = new Email(sender, recipients, subject, body, timestamp, attachments);
}
else
{
e = new Email(sender, recipients, subject, body, timestamp);
}
response = EmailServiceDetails.ADD_MAIL + EmailServiceDetails.COMMAND_SEPARATOR + EmailServiceDetails.formatEmail(e);
return response;
}
public static String viewUnread(Scanner keyboard)
{
System.out.println("Please enter the name of the email account you wish to see unread mail for:");
String recipient = keyboard.nextLine();
String response = EmailServiceDetails.VIEW_UNREAD + EmailServiceDetails.COMMAND_SEPARATOR + recipient;
return response;
}
}
--------------------------------------------------------------------------------
This is Server
---------------
package Server;
import Server.Commands.Command;
import core.EmailServiceDetails;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
public class EmailServer {
public static void main(String[] args) {
try{
// Set up a connection socket for other programs to connect to
ServerSocket listeningSocket = new ServerSocket(EmailServiceDetails.LISTENING_PORT);
// Create the list of emails to be stored and worked with
EmailStore emails = new EmailStore();
boolean continueRunning = true;
int threadCount = 0;
while(continueRunning)
{
// Step 2) wait for incoming connection and build communications link
Socket dataSocket = listeningSocket.accept();
threadCount++;
System.out.println("The server has now accepted " + threadCount + " clients");
// Step 3) Build thread
// Thread should be given:
// 1) a group to be stored in
// 2) a name to be listed under
// 3) a socket to communicate through
// 4) Any extra information that should be shared
EmailThread newClient = new EmailThread (emails, dataSocket.getInetAddress()+"", dataSocket,threadCount);
newClient.start();
}
listeningSocket.close();
}
catch(Exception e)
{
System.out.println("An error occurred: " + e.getMessage());
}
}
}
--------------------------------------------------------------------------------
This is ServerThread
---------------
package Server;
import Server.Commands.Command;
import Server.EmailStore;
import core.EmailServiceDetails;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Date;
import java.util.Scanner;
/**
*
* @author User
*/
public class EmailThread extends Thread {
private Socket dataSocket;
private Scanner input;
private PrintWriter output;
private int number;
private EmailStore emails;
public EmailThread(EmailStore emails,String name, Socket dataSocket, int number) {
try {
// Save the data socket used for communication between the thread and the Client
this.dataSocket = dataSocket;
// Save the id of the thread to identify output
// Save the id of the thread to identify output
this.number = number;
input = new Scanner(new InputStreamReader(this.dataSocket.getInputStream()));
// Create the stream for writing to the Client
output = new PrintWriter(this.dataSocket.getOutputStream(), true);
} catch (IOException e) {
System.out.println("An exception occurred while setting up connection links for a thread: " + e.getMessage());
}
}
@Override
public void run() {
{
String incomingMessage = "";
String response;
try {
while (!incomingMessage.equals(EmailServiceDetails.END_SESSION)) {
// Wipe the response to make sure we never use an old value
response = null;
// take in information from the client
incomingMessage = input.nextLine();
System.out.println("Received message: " + incomingMessage);
// Break up information into components
String[] components = incomingMessage.split(EmailServiceDetails.COMMAND_SEPARATOR);
// Confirm that the command was correctly formatted
// Did it include more than just the command text?
if (components.length > 1) {
CommandFactory factory = new CommandFactory();
// Figure out which command was sent by the client
// I.e. what does the client want to do?
Command command = factory.createCommand(components[0]);
// Take the remaining text the client sent (i.e. all the information provided)
// and execute the requested action (e.g. store the new mail, get all sent mails etc)
response = command.createResponse(components[1], emails);
} else if (components[0].equals(EmailServiceDetails.END_SESSION)) {
response = EmailServiceDetails.SESSION_TERMINATED;
} else {
// If information was missing, set the response to inform the
// client that the command wasn't recognised
response = EmailServiceDetails.UNRECOGNISED;
}
// Send back the computed response
output.println(response);
output.flush();
}
} catch (Exception e) {
System.out.println("An exception occurred while communicating with client #" + number + ": " + e.getMessage());
} finally {
try {
// Shut down connection
System.out.println("\n* Closing connection with client #" + number + "... *");
dataSocket.close();
} catch (IOException e) {
System.out.println("Unable to disconnect: " + e.getMessage());
System.exit(1);
}
}
}
}
}
--------------------------------------------------------------------------------
This is EmailStore
---------------
package Server;
import core.Email;
import java.util.ArrayList;
import java.util.stream.Collectors;
public class EmailStore
{
private ArrayList<Email> emailList = new ArrayList();
public boolean addMail(Email newEmail)
{
return emailList.add(newEmail);
}
public boolean removeMail(Email mailToBeDeleted)
{
return emailList.remove(mailToBeDeleted);
}
public ArrayList<Email> findEmailByRecipient(String recipient)
{
ArrayList<Email> results = new ArrayList();
results = (ArrayList<Email>) emailList.stream()
// Find all emails whose recipients list contents the specified recipient
.filter(email -> email.getRecipients().contains(recipient))
// Collect the results back into a List (this does not return an ArrayList, so need to cast)
.collect(Collectors.toList());
return results;
}
public ArrayList<Email> findEmailBySender(String sender)
{
ArrayList<Email> results = new ArrayList();
results = (ArrayList<Email>) emailList.stream()
// Find all emails matching the specified sender
.filter(email -> email.getSender().equals(sender))
// Collect the results back into a List (this does not return an ArrayList, so need to cast)
.collect(Collectors.toList());
return results;
}
// Methods to mark emails as read
// Provide a version that marks multiple mails as read AND a version that
// marks a single email as read
public void markMultipleAsRead(ArrayList<Email> emails)
{
for(Email e : emails)
{
markAsRead(e);
}
}
public void markAsRead(Email e)
{
int index = emailList.indexOf(e);
if(index != -1)
{
Email storedMail = emailList.get(index);
storedMail.markAsRead(true);
}
}
// Methods to mark emails as spam
// Provide a version that marks multiple mails as spam AND a version that
// marks a single email as spam
public void markAsSpam(Email e)
{
int index = emailList.indexOf(e);
if(index != -1)
{
Email storedMail = emailList.get(index);
storedMail.markAsSpam(true);
}
}
public void markMultipleAsSpam(ArrayList<Email> emails)
{
for(Email e : emails)
{
markAsSpam(e);
}
}
public ArrayList<Email> findUnreadEmailByRecipient(String recipient)
{
ArrayList<Email> results = new ArrayList();
results = (ArrayList<Email>) emailList.stream()
// Find all emails whose recipients list contents the specified recipient AND the email is not unread
.filter(email -> email.getRecipients().contains(recipient) && !email.isRead())
// Collect the results back into a List (this does not return an ArrayList, so need to cast)
.collect(Collectors.toList());
return results;
}
}
-------
Help Appreciated
-
----------
随着挫折程度的提高，帮助将非常受欢迎!!
答案 0 :(得分：0)
这个答案是一个疯狂的猜测但是在主方法的switch语句的情况1中，你调用的是input.nextLine（）扫描程序，它当时可能不包含信息。您可能必须首先使用hasNext（）方法检查数据是否到达。
同样在收集电子邮件类的最后一种方法中，您不需要强制转换。可以这样做：
results = emailList.stream()
.filter(email -> email.getRecipients().contains(recipient) && !email.isRead())
.collect(Collectors.toCollection(ArrayList::new));