There is a difference between testing via Console or via TextFile. If I read from Console the program expects a Stream and it will wait for further Input. When testing via Input from Textfile (still with System.in for the Scanner, using Java Program ) the hasNext() will return false at the end of the file … Read more
What am I doing wrong? Using multiple scanners on the same stream is the underlying problem. Scanners can (and will) consume the stream – this may (will) lead to unexpected side-effects. Best not to do it. If the input is closed, then the input (but Strings have no close method) is closed for everyone – … Read more
You have a single extra newline at the end of your file. hasNextLine() checks to see if there is another linePattern in the buffer. hasNext() checks to see if there is a parseable token in the buffer, as separated by the scanner’s delimiter. Since the scanner’s delimiter is whitespace, and the linePattern is also white … Read more
It’s possible that you are calling a method like nextInt() before. Thus a program like this: Scanner scanner = new Scanner(System.in); int pos = scanner.nextInt(); System.out.print(“X: “); String x = scanner.nextLine(); System.out.print(“Y: “); String y = scanner.nextLine(); demonstatres the behavior you’re seeing. The problem is that nextInt() does not consume the ‘\n’, so the next … Read more
Use an URL instead of File for any access that is not on your local computer. URL url = new URL(“http://www.puzzlers.org/pub/wordlists/pocket.txt”); Scanner s = new Scanner(url.openStream()); Actually, URL is even more generally useful, also for local access (use a file: URL), jar files, and about everything that one can retrieve somehow. The way above interprets … Read more
You are always reading the line twice (unless you get a *) if(scan.nextLine().equals(“*”)) // read here – “someString” break; words.add(scan.nextLine()); // ignore last read line and read again. You read only once and then compare. String value = scan.nextLine(); // check for null / empty here if (value.equals(“*”)) break; words.add(value);
The problem is that nextLine() “Advances this scanner past the current line”. So when you call nextLine() in the while condition, and don’t save the return value, you’ve lost that line of the user’s input. The call to nextLine() on line 3 returns a different line. You can try something like this Scanner scanner=new Scanner(System.in); … Read more
The hasNextInt call blocks until it has enough information to make the decision of “yes/no”. Press Ctrl+Z on Windows (or Ctrl+D on “unix”) to close the standard input stream and trigger an EOF. Alternatively, type in a non-integer and press enter. Console input is normally line-buffered: enter must be pressed (or EOF triggered) and the … Read more
This is because you are using Scanner#next method. And if you look at the documentation of that method, it returns the next token read. So, when you read user input using next method, it does not read the newline at the end. Which is then read by the nextLine() inside the while loop. And thus, … Read more
This works using java.util.Scanner and will take multiple “enter” keystrokes: Scanner scanner = new Scanner(System.in); String readString = scanner.nextLine(); while(readString!=null) { System.out.println(readString); if (readString.isEmpty()) { System.out.println(“Read Enter Key.”); } if (scanner.hasNextLine()) { readString = scanner.nextLine(); } else { readString = null; } } To break it down: Scanner scanner = new Scanner(System.in); String readString = … Read more