这是我目前的代码。由于某种原因，我不断得到并且调用了错误：NoSuchElementException：找不到行。例外情况发生在以下行：
"String number = scanPhone.nextLine();"
和提供者类以及行中："provObj.readCellPhoneFile(fileNameIn);"
在CellPhonesPart2类中。有谁知道它有什么问题？
import java.util.Scanner;
import java.io.File;
import java.util.Arrays;
import java.io.IOException;
public class Provider {
private String name;
private CellPhone[] phones;
private String[] excludedRecords;
/**
* Constructor for Provider class.
*/
public Provider() {
name = "not yet assigned";
phones = new CellPhone[0];
excludedRecords = new String[0];
}
/**
* Reads in file name and assigns data.
*
* @param fileNameIn Input for file name from main
* @throws IOException from scanning file name
*/
public void readCellPhoneFile(String fileNameIn) throws IOException {
//Reads in file name and creates Scanner object
File fileIn = new File(fileNameIn);
Scanner scanFile = new Scanner(fileIn);
//Assigns name from first line
name = scanFile.nextLine();
//Assigns data from file to different categories
while (scanFile.hasNext()) {
Scanner scanPhone = new Scanner(scanFile.nextLine());
scanPhone.useDelimiter(", *");
String phoneType = scanPhone.nextLine();
char phoneChar = phoneType.toUpperCase().charAt(0);
//Assigns phone to different category
switch (phoneChar) {
case 'F':
String number = scanPhone.nextLine();
int texts = Integer.parseInt(scanPhone.nextLine());
int minutes = Integer.parseInt(scanPhone.nextLine());
FlipPhone flip1 = new FlipPhone(number, texts, minutes);
addPhone(flip1);
break;
case 'S':
number = scanPhone.nextLine();
texts = Integer.parseInt(scanPhone.nextLine());
minutes = Integer.parseInt(scanPhone.nextLine());
int data = Integer.parseInt(scanPhone.nextLine());
SmartPhone smart1 = new SmartPhone(number, texts, minutes, data);
addPhone(smart1);
break;
case 'I':
number = scanPhone.nextLine();
texts = Integer.parseInt(scanPhone.nextLine());
minutes = Integer.parseInt(scanPhone.nextLine());
data = Integer.parseInt(scanPhone.nextLine());
int iMessages = Integer.parseInt(scanPhone.nextLine());
IPhone iPhone1 = new IPhone(number, texts,
minutes, data, iMessages);
addPhone(iPhone1);
break;
case 'A':
number = scanPhone.nextLine();
texts = Integer.parseInt(scanPhone.nextLine());
minutes = Integer.parseInt(scanPhone.nextLine());
data = Integer.parseInt(scanPhone.nextLine());
int hotspotMin = Integer.parseInt(scanPhone.nextLine());
Android android1 = new Android(number, texts,
minutes, data, hotspotMin);
addPhone(android1);
break;
default:
String unrecognized = scanPhone.nextLine();
addExcludedRecord(unrecognized);
}
}
}
/**
* Returns string for provider name.
*
* @return String
*/
public String getName() {
return name;
}
/**
* Assigns a name input as provider name.
*
* @param nameIn Input for provider name
*/
public void setName(String nameIn) {
name = nameIn;
}
/**
* Returns CellPhone array for phones.
*
* @return CellPhone[]
*/
public CellPhone[] getPhones() {
return phones;
}
/**
* Returns string array for excluded records.
*
* @return String[]
*/
public String[] getExcludedRecords() {
return excludedRecords;
}
/**
* Adds phone to array of phones.
*
* @param newPhoneIn Input for phone object
*/
public void addPhone(CellPhone newPhoneIn) {
//Increases size of phones array
CellPhone[] newPhones = new CellPhone[phones.length + 1];
for (int i = 0; i < phones.length; i++) {
newPhones[i] = phones[i];
}
phones = newPhones;
//Adds CellPhone object to phones array
phones[phones.length] = newPhoneIn;
}
/**
* Determines if phone number is found and deleted.
*
* @return boolean
* @param numberIn Input for phone number
*/
public boolean deletePhone(String numberIn) {
boolean delete = false;
int deleteIndex = -1;
//Searches for phone number match
for (int i = 0; i < phones.length; i++) {
if (numberIn == phones[i].getNumber()) {
deleteIndex = i;
//Decreases size of phones array
CellPhone[] newPhones = new CellPhone[phones.length - 1];
for (i = 0; i < phones.length; i++) {
newPhones[i] = phones[i];
}
phones = newPhones;
}
}
if (deleteIndex > -1) {
for (int i = deleteIndex; i < phones.length - 1; i++) {
phones[i] = phones[i + 1];
}
return true;
}
else {
return false;
}
}
/**
* Adds unrecognized phone to excluded records.
*
* @param excRecIn Input for unrecognized phone
*/
public void addExcludedRecord(String excRecIn) {
//Increases capacity of excludedRecords
String[] newExcRecords = new String[excludedRecords.length + 1];
for (int i = 0; i < excludedRecords.length; i++) {
newExcRecords[i] = excludedRecords[i];
}
excludedRecords = newExcRecords;
//Adds excRecIn to array
excludedRecords[excludedRecords.length] = excRecIn;
}
/**
* Returns list of cell phones in phones array.
*
* @return String
*/
public String toString() {
String result = "";
for (CellPhone phone : phones) {
result += phone;
}
return result;
}
/**
* Calculates total bill for all phones.
*
* @return double
*/
public double calculateTotalBill() {
double totalBill = 0;
for (int i = 0; i < phones.length; i++) {
totalBill += phones[i].calculateBill();
}
return totalBill;
}
/**
* Calculates total number of texts for all phones.
*
* @return int
*/
public int calculateTotalTexts() {
int totalTexts = 0;
for (int i = 0; i < phones.length; i++) {
totalTexts += phones[i].getTexts();
}
return totalTexts;
}
/**
* Calculates total number of minutes for all phones.
*
* @return int
*/
public int calculateTotalMinutes() {
int totalMinutes = 0;
for (int i = 0; i < phones.length; i++) {
totalMinutes += phones[i].getMinutes();
}
return totalMinutes;
}
/**
* Calculates total data for smartphones.
*
* @return int
*/
public int calculateTotalData() {
int totalData = 0;
for (int i = 0; i < phones.length; i++) {
if (phones[i] instanceof SmartPhone) {
totalData += ((SmartPhone) phones[i]).getData();
}
}
return totalData;
}
/**
* Calculates total hotspot minutes for Androids.
*
* @return int
*/
public int calculateTotalHotspotMin() {
int totalHotspotMin = 0;
for (int i = 0; i < phones.length; i++) {
if (phones[i] instanceof Android) {
totalHotspotMin += ((Android) phones[i]).getHotspotMin();
}
}
return totalHotspotMin;
}
/**
* Calculates total iMessage count for iPhones.
*
* @return int
*/
public int calculateTotalIMessages() {
int totalIMessages = 0;
for (int i = 0; i < phones.length; i++) {
if (phones[i] instanceof IPhone) {
totalIMessages += ((IPhone) phones[i]).getIMessages();
}
}
return totalIMessages;
}
/**
* Returns string for summary report.
*
* @return String
*/
public String summary() {
String summary = "------------------------------"
+ "\nSummary for " + getName()
+ "\n------------------------------"
+ "\nNumber of cell phones: " + getPhones()
+ "Texts: " + calculateTotalTexts()
+ "Talk Minutes: " + calculateTotalMinutes()
+ "Data: " + calculateTotalData()
+ "Hotspot Minutes: " + calculateTotalHotspotMin()
+ "iMessages: " + calculateTotalIMessages()
+ "Bill Total: $" + calculateTotalBill()
+ "\n\n------------------------------"
+ "\nRates for " + getName()
+ "\n------------------------------"
+ rates()
+ "\n------------------------------"
+ "\nCell Phones by Number"
+ "\n------------------------------\n"
+ listByNumber()
+ "\n------------------------------"
+ "\nCell Phones by Billing Amount"
+ "\n------------------------------\n"
+ listByBill()
+ "\n------------------------------"
+ "\nExcluded Records"
+ "\n------------------------------\n"
+ excludedRecordsList();
return summary;
}
/**
* Returns string for different rates.
*
* @return String
*/
public String rates() {
String rates = "FlipPhone Talk Rate: $" + FlipPhone.TALK_RATE
+ "\tText Rate: $" + FlipPhone.TEXT_RATE
+ "SmartPhone Talk Rate: $" + SmartPhone.TALK_RATE
+ "\tText Rate: $" + SmartPhone.TEXT_RATE
+ "\tMax Talk Time: " + SmartPhone.MAX_TALK_TIME
+ "\n\tiPhone iMessage Rate: $" + IPhone.IMESSAGE_RATE
+ "\n\tAndroid HotspotRate: $" + Android.HOTSPOT_RATE;
return rates;
}
/**
* Returns string of phones sorted by number.
*
* @return String
*/
public String listByNumber() {
String listByNumber = "";
for (CellPhone phone : phones) {
listByNumber += phone.toString();
}
Arrays.sort(phones);
return listByNumber;
}
/**
* Returns string of phones sorted by bill.
*
* @return String
*/
public String listByBill() {
String listByBill = "";
for (CellPhone phone : phones) {
listByBill += phone.toString();
}
Arrays.sort(phones, new CellPhoneBillComparator());
return listByBill;
}
/**
* Returns string excluded records.
*
* @return String
*/
public String excludedRecordsList() {
String excRecList = "";
for (String phone : excludedRecords) {
excRecList += phone;
}
return excRecList;
}
}
它从这个类中读取文件：
public class CellPhonesPart2 {
/**
* Creates objects from different classes and prints objects.
*
* @param args Reads in file
* @throws IOException from scanning input file
*/
public static void main(String[] args) throws IOException {
String fileNameIn = args[0];
Provider provObj = new Provider();
provObj.readCellPhoneFile(fileNameIn);
System.out.println(provObj.summary());
}
}
答案 0 :(得分：0)
你应该在调用nextLine（）之前使用适当的hasNext（）; 扫描仪可能是空的。！
答案 1 :(得分：0)
Scanner scanPhone = new Scanner(scanFile.nextLine());
// this is causing your error. scanPhone is ultimately just a one line String
// this line will be found
String phoneType = scanPhone.nextLine();
// this line won't because scanPhone is only one line
String number = scanPhone.nextLine();
编辑：可能的解决方案
while (scanFile.hasNextLine()) {
Scanner scanPhone = new Scanner(scanFile.nextLine());
scanPhone.useDelimiter(", *");
String phoneType = scanPhone.next();
char phoneChar = phoneType.toUpperCase().charAt(0);
//Assigns phone to different category
switch (phoneChar) {
case 'F':
String number = scanPhone.next();
int texts = Integer.parseInt(scanePhone.next());
int minutes = Integer.parseInt(scanPhone.next());
FlipPhone flip1 = new FlipPhone(number, texts, minutes);
addPhone(flip1);
break;
将所有scanPhone.nextLine()更改为scanPhone.next()
另外，请尝试使用while (scanFile.hasNextLine());代替hasNext()