使用 Scanner .hasNext(), .next 读取文件时比较字符串

Question

我正在努力为我的 Programm 争取一点高分。该程序有一个日志文件，我想读取该文件并确定获胜者。因为我的程序有一些问题，你可以一遍又一遍地回答同一个问题，并因此获得学分。 使用下面的代码，我试图防止作弊分数。我试图比较第三、第四和第五个字符串，它代表你必须解决的计算。当下一行具有相同的计算时，我想忽略高分的计数 有人可以帮我弄这个吗 ？我只是得到一堆错误。

感谢您的时间和帮助。

public int readFile() {
    String score = null;
    while (scan.hasNext()) {
        String a = scan.next();
        String b = scan.next();
        String c = scan.next();
        String d = scan.next();
        String e = scan.next();
        String f = scan.next();
        String g = scan.next();
        String h = scan.next();
        String i = scan.next();

        if (c.equals(scan.next()) && d.equals(scan.next()) && e.equals(scan.next())) {
        } else {
            temp = Integer.parseInt(i);
            if (temp > highscore) {
                highscore = temp;
            }
        }

    }
    return highscore;
}

文本文件：

    014/07/29 08:25:15  95 + 80 4       false       -171        0
    2014/07/29 08:25:15 95 + 80 4       false       -171        0
    2014/07/29 08:25:49 8 * 3   24      true        0       1
    2014/07/29 08:25:49 8 * 3   24      true        0       2
    2014/07/29 08:25:49 8 * 3   24      true        0       3
    2014/07/29 08:25:50 8 * 3   24      true        0       4
    2014/07/29 08:25:50 8 * 3   24      true        0       5

错误：

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "2014/07/28"
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at mathe.Highscore.readFile(Highscore.java:42)
    at mathe.Gui$TestActionListener.actionPerformed(Gui.java:231)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$200(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

如果您在条件语句中继续使用 scan.next，您的扫描器将扫描下一个值。我认为您希望获得下一个值并用于比较。

public int readFile() {
    String score = null;
    while (scan.hasNext()) {
        String a = scan.next();
        String b = scan.next();
        String c = scan.next();
        String d = scan.next();
        String e = scan.next();
        String f = scan.next();
        String g = scan.next();
        String h = scan.next();
        String i = scan.next();

        String nextVal = scan.next();

        if (c.equals(nextVal) && d.equals(nextVal) && e.equals(nextVal)) {
        } else {
            temp = Integer.parseInt(i);
            if (temp > highscore) {
                highscore = temp;
            }
        }

    }
    return highscore;
}

我希望这会有所帮助。 干杯..！

Answer 2

在 if 语句中调用 scan.next() 是个坏主意。第二个 scan.next 只有在第一个 equals 为真时才会被调用，以此类推，因此很容易混淆您要阅读的列。将那些 scan.next 移出 if 语句以供初学者使用。

根据错误消息，您正在对日期字符串调用 Integer.parseInt(i);。

您似乎正在尝试查找文件中的最大数字？你应该做的是存储最高的 int，它是在循环外声明的。例如

int Highscore = 0;
while (...) {
   .... 

  int num = Integer.parseInt(i);
  if (num > Highscore) {
    Highscore = num;
  } 

如果你明白我的意思。