问题描述
我需要获取文件名字符串，然后尝试打开该文件。如果找不到该文件，我将进行循环，直到输入正确的字符串。
public static void main(String[] args){
// Get file string until valid input is entered.
System.out.println("Enter file name.
Enter ';' to exit.");
String fileName = sc.nextLine();
boolean fileLoop = true;
InputStream inFile;
while (fileLoop){
try{
inFile = new FileInputStream(fileName);
fileLoop = false;
} catch (FileNotFoundException e) {
System.out.println("That file was not found.
Please re enter file name.
Enter ';' to exit.");
fileName = sc.nextLine();
if (fileName.equals(";")){
return;
}
}
}
// ****** This is where the error is. It says inFile may not have been initalized. ***
exampleMethod(inFile);
}
public static void exampleMethod(InputStream inFile){
// Do stuff with the file.
}
当我尝试调用exampleMethod(InFile)时，NetBeans告诉我InputStream inFile可能尚未初始化。我认为这是因为赋值位于try Catch块内。正如大家所看到的，我尝试在循环外部声明对象，但没有成功。
我还尝试使用以下内容在循环外部初始化输入流：
InputStream inFile = new FileInptStream();
// This yeilds an eror because there are no arguments.
还有这个：
InputStream inFile = new InputStream();
// This doesn't work because InputStream is abstract.
如何确保在初始化此InputStream的同时仍允许循环，直到输入有效输入？
谢谢
推荐答案
要修复此问题，请更改以下代码行：
InputStream inFile;
至此：
InputStream inFile = null;