编辑：现在唯一不起作用的是选项编号7的以下代码.persenger [i] [4]中的年龄是整数或浮点类型。该程序开始打印出小于10岁的人的名字，但在打印出int而不是浮动之后停止。该程序在此之后立即退出。
public int getPassWhoYoung() {
System.out.println("The passengers younger than 10:");
int count = 0;
for(int i = 0; i < passengers.length; i++){
if(passengers[i][4] != null && passengers[i][1].equals("1")){
double x = Double.valueOf(passengers[i][4]);
if(x < 10){
System.out.println(passengers[i][2]);
}
count++;
}
}
System.out.println("The passengers under 10 who survived: ");
return count;
}
原始问题： 我正在尝试创建一个程序，使用循环来读取文本文件的每一行并分隔每种数据类型。考虑到这一点，每行不包含每种数据类型。每条线路都是泰坦尼克号上的不同乘客。第一个数字是他们所在的班级，第二个数字是他们是否死了（0如果他们死了，1他们住了），他们的名字（姓氏，头衔，头等，中间），性别，年龄和价格他们支付了他们的机票。这是文件的第一行：＆＃34; 1 1 Allen，Miss.Elisabeth Walton女29 211.3375＆＃34;
到目前为止，这是我的进展：
main
import java.time.Duration;
import java.time.Instant;
import java.util.Scanner;
import java.io.*;
public class TitanicProgram {
public static void main(String[] args) throws IOException {
String choice;
boolean loop = true;
String titanicFile = "Titanic.txt";
Scanner scannerIn = new Scanner(System.in);
// Uses Time at start
Instant before = Instant.now();
Passenger p = new Passenger(titanicFile);
System.out.println("********** Welcome to the Titanic Statistical" +
" Application **************************");
while (loop == true) {
System.out.println("Enter the number of the question you want answered."
+ " Enter ‘Q’ to quit the program :\n"
+ "1. How many passengers were on the Titanic?\n" +
"2. What percentage of passengers perished on the Titanic?\n" +
"3. What percentage passengers survived the sinking of the Titanic?\n" +
"4. What percentage of passengers survived for each of the three classes?\n" +
"5. What percentage of passengers survived as a function of gender?\n" +
"6. What specific passengers paid more than $200 for their tickets?\n" +
"7. What specific passengers who were less than 10 years old perished on the titanic?\n" +
"8. What specific passengers who were less than 10 years old survived the sinking of the titanic?\n" +
"9. For each letter in the alphabet, how many passengers last names started with that letter?\n" +
"Q. Quit the program\n\n" + "Enter your selection: ");
choice = scannerIn.nextLine();
switch (choice) {
case "1": System.out.println("The total number of passengers: "
+ p.readLines() + "\n");
break;
case "2": System.out.println("2!");
break;
case "3": System.out.println("3!");
break;
case "4": System.out.println("4!");
break;
case "5": System.out.println("5!");
break;
case "6": System.out.println("6!");
break;
case "7": System.out.println("7!");
break;
case "8": System.out.println("8!");
break;
case "9": System.out.println("9!");
break;
case "Q": System.out.println("Thank you for trying the" +
" Titanic Program!");
loop = false;
break;
default: System.out.println("Enter a valid Option!");
}
}
Instant after = Instant.now();
System.out.println("Elapsed time in seconds was: " +
Duration.between(before, after).toNanos()/1_000_000_000.0);
}
}
这是乘客班（我知道它非常糟糕，它正在进行中）：
package titanicprogram;
import java.io.*;
import java.util.Scanner;
// I am still working on this, not too much progress yet
public class Passenger {
private int totalPass = 0;
private int passWhoDied = 0;
private int passWhoLived = 0;
private int malePassLived = 0;
private int femalePassLived = 0;
private String namePassCost;
private String nameKidsDied;
private String nameKidsLived;
// Testing
private int passClass;
private int passSurvived;
private String lastName;
private String passTitle;
private String firstName;
private String midName;
private String genderFemale;
private String genderMale;
private int age;
private float price;
//private String[] lastNames;
private Scanner scan;
private String path;
public Passenger(String filePath) {
path = filePath;
}
public String[] OpenFile() throws IOException {
FileReader fr = new FileReader(path);
BufferedReader textReader = new BufferedReader(fr);
int numberOfLines = readLines();
String[ ] textData = new String[numberOfLines];
for (int i=0; i < numberOfLines; i++) {
textData[ i ] = textReader.readLine();
textData[i] = textReader.readLine( );
}
textReader.close( );
return textData;
}
public int readLines() throws IOException {
FileReader fr1 = new FileReader(path);
BufferedReader textReader1 = new BufferedReader(fr1);
String eachLine;
int numberOfLines = 0;
while ( ( eachLine = textReader1.readLine( ) ) != null ) {
numberOfLines++;
}
while(scan.hasNext()){
if (scan.hasNextInt()) {
passClass = scan.nextInt();
}
if (scan.hasNextInt()) {
passSurvived = scan.nextInt();
} else {
scan.next();
}/*
passClass = scan.nextInt();
passSurvived = scan.nextInt();
lastName = scan.next();
passTitle = scan.next();
firstName = scan.next();
midName = scan.next();
genderFemale = scan.findInLine("female");
genderMale = scan.findInLine("male");
age = scan.nextInt();
price = scan.nextFloat();
System.out.printf(passTitle, lastName);
*/
}
return numberOfLines;
}
/*
public void openFile(){
try{
scan = new Scanner(new File("Titanic.txt"));
}
catch(Exception e){
System.out.println("File not found!");
}
}
public void readFile() throws IOException {
while(scan.hasNext()){
int passClass = scan.nextInt();
int passSurvived = scan.nextInt();
String lastName = scan.next();
String passTitle = scan.next();
String firstName = scan.next();
String midName = scan.next();
String genderFemale = scan.findInLine("female");
String genderMale = scan.findInLine("male");
int age = scan.nextInt();
float price = scan.nextFloat();
System.out.printf(passTitle, lastName);
}
}
public void closeFile() {
scan.close();
}
*/
// Getter methods
public int getTotalPass() {
return totalPass;
}
public int getPassWhoDied() {
return passWhoDied;
}
public int getPassWhoLived() {
return passWhoLived;
}
public int getMalePassLived() {
return malePassLived;
}
public int getFemalePassLived() {
return femalePassLived;
}
public String getNamePassCost() {
return namePassCost;
}
public String getNameKidsDied() {
return nameKidsDied;
}
public String getNameKidsLived() {
return nameKidsLived;
}
}
答案 0 :(得分：1)
试试这个。我使用StringTokenizer使事情变得更容易和更直观。
//USE MAP FOR SAVE PEOPLE
private static Map<String, Integer> passengers;
private static BufferedReader innerReader;
public static List<String> loadFile(Reader reader)
throws IllegalArgumentException, IOException {
//YOU CAN REPLACE STRING WITH YOURS CUSTOM TYPE
List<String> fileList = new ArrayList<String>();
//INITIALIZE MAP
passengers = new HashMap<String, Integer>();
if(reader == null)
{
throw new IllegalArgumentException("Reader non valido");
}
innerReader = new BufferedReader(reader);
String line;
try
{
while((line = innerReader.readLine()) != null)
{
if (line == null || line.trim().isEmpty())
throw new IllegalArgumentException(
"Line Empty");
StringTokenizer tokenizer = new StringTokenizer(line);
int classInt, liveOrDeadInt, ageInt;
double priceDouble;
String classes = tokenizer.nextToken(" ").trim();
String liveOrDead = tokenizer.nextToken(" ").trim();
String lastName = tokenizer.nextToken(",").trim();
String titleName = tokenizer.nextToken(",.").trim();
String firstName = tokenizer.nextToken("\\. ").trim();
String middleName = tokenizer.nextToken("\\. ").trim();
String gender = tokenizer.nextToken("0123456789").trim();
String age = tokenizer.nextToken(" ").trim();
String price = tokenizer.nextToken("\n\r").trim();
StringBuilder sb = new StringBuilder();
//IF YOU WOULD CHECK NUMBER CONVERSION DO
try
{
classInt = Integer.parseInt(classes);
}catch(Exception e){
throw new IllegalArgumentException(e);
}
try
{
liveOrDeadInt = Integer.parseInt(liveOrDead);
}catch(Exception e){
throw new IllegalArgumentException(e);
}
try
{
ageInt = Integer.parseInt(age);
}catch(Exception e){
throw new IllegalArgumentException(e);
}
try
{
priceDouble = Double.parseDouble(price);
}catch(Exception e){
throw new IllegalArgumentException(e);
}
//CHECK IF ARE ALIVE AND HAVE LESS THAN 10 YEARS
if(ageInt < 10 && liveOrDeadInt == 1)
{
sb.append(lastName + ", " + titleName +
". " + firstName + " " + middleName);
passengers.put(sb.toString(), ageInt);
}
//EMPTY STRING BUILDER
sb.delete(0, sb.length());
sb.append(classes + " " + liveOrDead + " " + lastName + ", " + titleName +
". " + firstName + " " + middleName + " " + gender + " " + age +
" " + price);
//READ FILE SUCCESS
fileList.add(sb.toString());
}
} catch (NoSuchElementException | NumberFormatException e) {
throw new IllegalArgumentException(e);
}
return fileList;
}
public static void close() {
try {
innerReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
使用此主菜：
List<String> test = new ArrayList<String>();
try {
test = loadFile(new FileReader("FileName.txt"));
} catch (IllegalArgumentException | IOException e) {
e.printStackTrace();
}
close();
for(String s : test)
{
System.out.println(s);
}
//SHOW PASSENGERS WHO SURVIVED
System.out.println("The passengers under 10 who survived: ");
Iterator it = passengers.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
System.out.println(entry.getKey() + " Age:" + entry.getValue());
}
System.out.println("Total passengers under 10 who survived: " + passengers.size());
//OR USE METHOD
showPassengers();
或者这样做：
public static void showPassengers()
{
System.out.println("The passengers under 10 who survived: ");
Iterator it = passengers.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
System.out.println(entry.getKey() + " Age:" + entry.getValue());
}
System.out.println("Total passengers under 10 who survived: " + passengers.size());
}
制作这个新输出：
<1> 1艾伦，小姐。伊丽莎白沃尔顿女29 211.3375 <1> 1艾伦，小姐。伊丽莎白沃尔顿女29 211.33751 0 Allen，Miss.Eli Walton女9 211.3375
<1> 1艾伦，小姐。伊丽莎白沃尔顿女29 211.3375 <1> 1艾伦，小姐。伊丽莎白沃尔顿女29 211.3375 <1> 1艾伦，小姐。伊丽莎白沃尔顿女7 211.3375 <1> 1艾伦，伊丽莎白女士沃尔顿女士3 211.3375 <1> 1艾伦，小姐。伊丽莎白沃利女9 211.3375幸存下来的10岁以下乘客：
Allen，Miss.Elisabeth Wally年龄：9
Allen，Miss.Elisabeth Walton年龄：7
艾伦，伊丽莎白沃尔顿夫人年龄：3幸存的10岁以下乘客总数：3