如何(或)使用PrintWriter类实现输入扫描程序后输入“*”以保存文件和退出的逻辑？

Question

我试着做些这样的工作：

import java.io.PrintWriter;
import java.io.IOException;
import java.util.Scanner;
import static java.lang.System.in;
import static java.lang.System.out;


class PrintWrit1 
{
    public static void main(String[] args) 
    {
        Scanner input = new Scanner(in);
        out.print("Enter the filename :\t");
        String filename = input.nextLine();
        try(    PrintWriter pw = new PrintWriter(filename))
        {   
            out.println("Enter the file content, enter * after finishing");
            String text;
            while((text=input.nextLine()) != "*")
            {   pw.println(text);   }
            out.println(filename+" is saved and closed");
        }
        catch(IOException ioe)
        { ioe.printStackTrace();}
    }
}

文件被创建，输出被写入，但是当命中ctrl时，文件会被保存，但是下面的语句不会执行，它会突然终止。

如果我输入了*在输入最后一行后，它应该能够执行out.println(filename+" is saved and closed")

当前产出：

D:\JavaEx\FILE-IO>java PrintWrit1
Enter the filename :    sample
Enter the file content, enter * after finishing
line1
line2
*

预期产出：

D:\JavaEx\FILE-IO>java PrintWrit1
Enter the filename :    sample
Enter the file content, enter * after finishing
line1
line2
*
sample is saved and closed

Answer 1

您正在比较字符串* wrongly.You应该使用equals()方法。请更换

while((text=input.nextLine()) != "*")

至

while(!(text=input.nextLine()).equals("*"))