Question

Java键盘输入Scanner遇到bug

Scanner sc = new Scanner(System.in);
BufferedWriter bw = new BufferedWriter(new FileWriter("a.txt"));
System.out.println("请开始写作！要想结束，请以单独的\"end\"作为一行");
String line;
while((line=sc.nextLine())=="end"){
// while(((line=sc.nextLine()).equals("end"))){
System.out.println(line);
bw.write(line);
bw.newLine();
}
bw.close();
上面while小括号中如果是用equals的话，一直键入end一直循环，而用==的话键入end只循环一遍就结束了，这是为甚么呢？

Answer 1

在中间加上这行：Scanner scan1 = new Scanner(System.in);
sop("");
sop("请输入图书评分！");
double newScore = 0;
try{
newScore = scan1.nextDouble();
}