我的Java Swing Designer计算器赢得了'；不行。（按下“循环”的“等于”按钮时出错）

非常感谢您的帮助。我不熟悉swing、awt和java。

这个循环有问题：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 3
    at calculator.CalculatorWindow$16.actionPerformed(CalculatorWindow.java:198)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6516)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
    at java.awt.Component.processEvent(Component.java:6281)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4872)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4698)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4698)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:708)
    at java.awt.EventQueue$4.run(EventQueue.java:706)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

for（int buttonPressed=0；buttonPressed

具体地说，当

buttonPressed

>=

outputboxbuttonpressed.length-2

访问数组时，注释行上会出现错误，因为您访问的数组最多超过其结束位置两个元素。您可以通过将循环条件更改为

buttonPressed

来防止出现错误，但如果这会阻止代码工作或不工作，我不介意。

public void actionPerformed（ActionEvent e）{
for (int buttonPressed = 0; buttonPressed < outputBoxButtonsPressed.length; buttonPressed++) {
    if (outputBoxButtonsPressed[buttonPressed + 1].equals("+")) {
        answer = Integer
            .parseInt(outputBoxButtonsPressed[buttonPressed])
             + Integer
                 .parseInt(outputBoxButtonsPressed[buttonPressed + 2]); //here
        break;
    }
 }

字符串[]outputBoxButtonsPressed=outputBox.getText（）.split(
" ");
System.out.println（Arrays.toString（outputBoxButtonsPressed））；
int-answer=0；
布尔值firstOperatorBeenUsed=false；
对于（int buttonPressed=0；buttonPressed

---

这个新的equals按钮处理程序可以完美地处理所有按钮。耶：D

这是最直接不过的了

ArrayIndexOutOfBoundsException

表示试图访问不存在的数组元素。place System.out.println（Arrays.toString（outputBoxButtonsPressed））；在你第一次分配它的地方，我取出for循环，在actionPerformed（）中调试它，然后键入2+1，打印结果是[2，+，1]，就像它应该的那样。我不明白为什么它试图访问一个不存在的数组元素？？非常感谢。：）我真的很感谢你的帮助。

for (int buttonPressed = 0; buttonPressed < outputBoxButtonsPressed.length; buttonPressed++) {
    if (outputBoxButtonsPressed[buttonPressed + 1].equals("+")) {
        answer = Integer
            .parseInt(outputBoxButtonsPressed[buttonPressed])
             + Integer
                 .parseInt(outputBoxButtonsPressed[buttonPressed + 2]); //here
        break;
    }
 }

public void actionPerformed(ActionEvent e) {
    String[] outputBoxButtonsPressed = outputBox.getText().split(
            " ");
    System.out.println(Arrays.toString(outputBoxButtonsPressed));
    int answer = 0;
    boolean firstOperatorBeenUsed = false;

    for (int buttonPressed = 0; buttonPressed < outputBoxButtonsPressed.length - 2; buttonPressed++) {
        if (outputBoxButtonsPressed[buttonPressed + 1].equals("+")
                && !firstOperatorBeenUsed) {
            answer = answer
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed])
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);
            System.out.println(answer);
            firstOperatorBeenUsed = true;
        } else if (outputBoxButtonsPressed[buttonPressed + 1]
                .equals("+") && firstOperatorBeenUsed) {
            answer = answer
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);

        }
        if (outputBoxButtonsPressed[buttonPressed + 1].equals("-")
                && !firstOperatorBeenUsed) {
            answer = answer
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed])
                    - Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);
            System.out.println(answer);
            firstOperatorBeenUsed = true;
        } else if (outputBoxButtonsPressed[buttonPressed + 1]
                .equals("-") && firstOperatorBeenUsed) {
            answer = answer
                    - Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);

        }

        if (outputBoxButtonsPressed[buttonPressed + 1].equals("x")
                && !firstOperatorBeenUsed) {
            answer = answer
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed])
                    * Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);
            System.out.println(answer);
            firstOperatorBeenUsed = true;
        } else if (outputBoxButtonsPressed[buttonPressed + 1]
                .equals("x") && firstOperatorBeenUsed) {
            answer = answer
                    * Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);

        }

        if (outputBoxButtonsPressed[buttonPressed + 1].equals("÷")
                && !firstOperatorBeenUsed) {
            answer = answer
                    + Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed])
                    / Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);
            System.out.println(answer);
            firstOperatorBeenUsed = true;
        } else if (outputBoxButtonsPressed[buttonPressed + 1]
                .equals("÷") && firstOperatorBeenUsed) {
            answer = answer
                    / Integer
                            .parseInt(outputBoxButtonsPressed[buttonPressed + 2]);

        }

    }
    outputBox.setText(outputBox.getText() + " = " + answer);
}