我试图熟悉文件处理并在创建，编写然后读取文件后计算输入的整数之和。问题出在最后一步，总和将始终打印为最后输入的整数。如何才能使总和正常工作？代码段下方的完整代码以及控制台消息。
public static void readRecords()
{
try (BufferedReader br = new BufferedReader (new FileReader("numbers.txt"))){
String line;
int[] number = new int[10];
int i=-1;
while ((line = br.readLine()) != null) {
i++;
String[] split = line.split(":");
line = split[1].trim();
number[i] = Integer.parseInt(line);
System.out.printf("Integer number %d: %d%n", i, numbers[i]);
}
int sum = 0;
float average;
sum = sum+number[i];
System.out.printf("Cool . Your sum is %d%n", sum);
}
以下是完整的代码：
package average;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.lang.SecurityException;
import java.nio.file.NoSuchFileException;
import java.util.Formatter;
import java.util.FormatterClosedException;
import java.util.NoSuchElementException;
import java.util.InputMismatchException;
public class Average {
private static Formatter output;
static Scanner input = new Scanner(System.in);
static int[] numbers = new int[10];
public static void main(String[] args)
{
openFile();
addRecords();
closeFile();
readRecords();
// closeFile();
}
public static void openFile()
{
try
{
output = new Formatter("numbers.txt");
}
catch (SecurityException securityException)
{
System.err.println("Write permission denied. Terminating.");
System.exit(1);
}
catch (FileNotFoundException fileNotFoundException)
{
System.err.println("Error opening file. Terminating.");
System.exit(1);
}
}
public static void addRecords()
{
System.out.print("Hello, welcome to my program!\n");
for (int i = 0 ; i < 10 ; i++) {
System.out.printf("Please enter integer %d: ", i+1);
numbers[i] = input.nextInt();
{
try
{
output.format("Inputted integer: %s%n", String.valueOf(numbers[i]));
}
catch (FormatterClosedException formatterClosedexception)
{
System.err.println("Error writing to the file. Terminating.");
break;
}
catch (InputMismatchException inputMismatchException)
{
System.err.println("Please restart the program and enter integers ONLY.");
break;
}
catch (NoSuchElementException elementException)
{
System.err.println("Invalid input. Please try again.");
input.nextLine();
}
}
}
}
public static void closeFile(){
{
if (output != null)
output.close();
}
}
public static void readRecords()
{
try (BufferedReader br = new BufferedReader (new FileReader("numbers.txt"))){
String line;
int[] number = new int[10];
int i=-1;
while ((line = br.readLine()) != null) {
i++;
String[] split = line.split(":");
line = split[1].trim();
number[i] = Integer.parseInt(line);
System.out.printf("Integer number %d: %d%n", i, numbers[i]);
}
int sum = 0;
float average;
sum = sum+number[i];
System.out.printf("Cool . Your sum is %d%n", sum);
}
catch (NoSuchFileException noSuchFileException)
{
System.out.print("This file was not created properly and cannot be found.");
}
catch (FileNotFoundException fileNotFoundException)
{
System.out.print("I can't seem to find your file :( That's too bad...");
}
catch (IOException ioexception)
{
System.out.print("Whoopsie daisy, you got yourself an IOException. Better luck next time!");
}
finally
{
System.out.print("Check your numbers.txt file and see what ya got!");
}
}
}
答案 0 :(得分：2)
您的sum = sum+number[i];语句不在循环中，因此您只需将最后一个数字添加到总和中。
你应该在循环内添加总和：
int sum = 0;
while ((line = br.readLine()) != null) {
i++;
String[] split = line.split(":");
line = split[1].trim();
number[i] = Integer.parseInt(line);
System.out.printf("Integer number %d: %d%n", i, numbers[i]);
sum += number[i];
}
答案 1 :(得分：0)
你的总和是在while循环中，所以它不计算在内。使用以下代码修复它：
int sum=0 ;
while ((line = br.readLine()) != null) {
i++;
String[] split = line.split(":");
line = split[1].trim();
number[i] = Integer.parseInt(line);
System.out.printf("Integer number %d: %d%n", i, numbers[i]);
sum+=number[i]; // Here!!
}
答案 2 :(得分：0)
试试这个
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.lang.SecurityException;
import java.nio.file.NoSuchFileException;
import java.util.Formatter;
import java.util.FormatterClosedException;
import java.util.NoSuchElementException;
import java.util.InputMismatchException;
public class Test {
private static Formatter output;
static Scanner input = new Scanner(System.in);
static int[] numbers = new int[10];
public static void main(String[] args)
{
openFile();
addRecords();
closeFile();
readRecords();
// closeFile();
}
public static void openFile()
{
try
{
output = new Formatter("numbers.txt");
}
catch (SecurityException securityException)
{
System.err.println("Write permission denied. Terminating.");
System.exit(1);
}
catch (FileNotFoundException fileNotFoundException)
{
System.err.println("Error opening file. Terminating.");
System.exit(1);
}
}
public static void addRecords()
{
System.out.print("Hello, welcome to my program!\n");
for (int i = 0 ; i < 3 ; i++) {
System.out.printf("Please enter integer %d: ", i+1);
numbers[i] = input.nextInt();
{
try
{
output.format("Inputted integer: %s%n", String.valueOf(numbers[i]));
}
catch (FormatterClosedException formatterClosedexception)
{
System.err.println("Error writing to the file. Terminating.");
break;
}
catch (InputMismatchException inputMismatchException)
{
System.err.println("Please restart the program and enter integers ONLY.");
break;
}
catch (NoSuchElementException elementException)
{
System.err.println("Invalid input. Please try again.");
input.nextLine();
}
}
}
}
public static void closeFile(){
{
if (output != null)
output.close();
}
}
public static void readRecords()
{
int sum = 0;
try (BufferedReader br = new BufferedReader (new FileReader("numbers.txt"))){
String line;
int[] number = new int[10];
int i=-1;
while ((line = br.readLine()) != null) {
i++;
String[] split = line.split(":");
line = split[1].trim();
number[i] = Integer.parseInt(line);
System.out.printf("Integer number %d: %d%n", i, numbers[i]);
}
float average;
for(int k : number){
sum = sum+k;}
System.out.printf("Cool . Your sum is %d%n", sum);
}
catch (NoSuchFileException noSuchFileException)
{
System.out.print("This file was not created properly and cannot be found.");
}
catch (FileNotFoundException fileNotFoundException)
{
System.out.print("I can't seem to find your file :( That's too bad...");
}
catch (IOException ioexception)
{
System.out.print("Whoopsie daisy, you got yourself an IOException. Better luck next time!");
}
finally
{
System.out.print("Check your numbers.txt file and see what ya got!");
}
}
}