我正在编写一些代码,该代码先获取用户文件,然后对信息进行排序,但是我在编写程序时遇到了麻烦,因此,如果用户输入了错误的文件名,该程序将不会停止,而是给他们另一个机会输入正确的文件。
我以为我可以通过do来做到这一点,这就是说要求文件在不存在但似乎无法正常工作时重复读取文件
public void readText(int ages[], String names[]) throws FileNotFoundException{
String filename = "";
Scanner inputFile = new Scanner(System.in);
do {
System.out.println("File to read from:");
filename = inputFile.nextLine();
File file = new File(filename);
inputFile = new Scanner(file);
}
while (!new File(filename).exists());
while (inputFile.hasNextLine()) {
String data = inputFile.nextLine();
String[] parts = data.split("(?<=\\))(?=\\()");
for (String part : parts) {
String input = part.replaceAll("[()]", "");
ages[count] = Integer.parseInt(input.split(", ")[0]);
names[count] = input.split(", ")[1];
count++;
}
}
}
[当我尝试输入一个不存在的伪文件时,它会要求文件再次读取我得到的内容和异常。例:要读取的文件:none.txt(不存在,只是要它再次问我)然后它给了我下面的例外:
Exception in thread "main" java.io.FileNotFoundException: nothing.txt (The system cannot find the file specified)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.util.Scanner.<init>(Scanner.java:611)
at PonySort.readText(PonySort.java:95)
at PonySort.main(PonySort.java:30)
您正在尝试使用第一个Scanner
循环中的文件创建一个do-while
,该文件会导致FileNotFoundException
。因此,请在找到有效文件后执行以下操作。
public void readText(int ages[], String names[]) throws FileNotFoundException{
String filename = "";
Scanner inputFile = new Scanner(System.in);
File file;
do {
System.out.println("File to read from:");
filename = inputFile.nextLine();
file = new File(filename);
} while (!file.exists());
inputFile = new Scanner(file);
while (inputFile.hasNextLine()) {
String data = inputFile.nextLine();
String[] parts = data.split("(?<=\\))(?=\\()");
for (String part : parts) {
String input = part.replaceAll("[()]", "");
ages[count] = Integer.parseInt(input.split(", ")[0]);
names[count] = input.split(", ")[1];
count++;
}
}
}