자바 오류 질문

게시물 수정 , 삭제는 로그인 필요

실행하면 다른 버튼들은 다 잘되는데 = 버튼은 누르면 아래 오류가 뜨는데 몇시간 째 해결책을 모르겠습니다..

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "9/3"

at java.base/jdk.internal.math.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2054)

at java.base/jdk.internal.math.FloatingDecimal.parseDouble(FloatingDecimal.java:110)

at java.base/java.lang.Double.parseDouble(Double.java:651)

at NCalculator.calculate(NCalculator.java:139)

at NCalculator$PadActionListener.actionPerformed(NCalculator.java:77)

at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1972)

at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2313)

at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)

at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)

at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)

at java.desktop/java.awt.Component.processMouseEvent(Component.java:6616)

at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3398)

at java.desktop/java.awt.Component.processEvent(Component.java:6381)

at java.desktop/java.awt.Container.processEvent(Container.java:2266)

at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4991)

at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2324)

at java.desktop/java.awt.Component.dispatchEvent(Component.java:4823)

at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4948)

at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4575)

at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4516)

at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2310)

at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)

at java.desktop/java.awt.Component.dispatchEvent(Component.java:4823)

at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:775)

at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)

at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)

at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)

at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)

at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)

at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:747)

at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)

at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)

at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)

at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:744)

at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)

at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)

at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)

at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)

at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)

at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

------------코드 부분

public class NCalculator extends JFrame {

private JPanel panel;

private JTextField inputSpace;

    private JButton[] buttons;

    private String num ="";

    private ArrayList<String> equation = new ArrayList<String>();

private String[] labels = { 

"Backspace", "", "", "CE", "C",

"7", "8", "9", "/", "sqrt",

"4", "5", "6", "x", "%",

"1", "2", "3", "-", "1/x",

"0", "+/-", ".", "+", "=",

};

public NCalculator() {

inputSpace = new JTextField(35);

panel = new JPanel();

inputSpace.setText(" ");

inputSpace.setEnabled(false);

panel.setLayout(new GridLayout(0, 5, 3, 3));

buttons = new JButton[25];

int index = 0;

for (int rows = 0; rows < 5; rows++) {

for (int cols = 0; cols < 5; cols++) {

buttons[index] = new JButton(labels[index]);

if( cols >= 3 )

buttons[index].setForeground(Color.red);

else 

buttons[index].setForeground(Color.blue);

buttons[index].setBackground(Color.yellow);

buttons[index].addActionListener(new PadActionListener());

panel.add(buttons[index]);

index++;

}

}

setTitle("계산기");

add(panel, BorderLayout.CENTER);

add(inputSpace, BorderLayout.NORTH);

setLocationRelativeTo(null); 

setVisible(true);

pack();

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

class PadActionListener implements ActionListener{

public void actionPerformed(ActionEvent e) {

//어떤 버튼이 눌렸는지를 알아냄

String operation = e.getActionCommand();

//C가 눌렸을 경우 위의 계산식 내용을 지워줌

if (operation.equals("C")) {

inputSpace.setText("");

//=이 눌렸을 경우 위에 입력된 식을 계산, 계산값이 나오도록 함

} else if (operation.equals("=")) {

//밑의 메소드들을 이용하여 계산, 계산식 화면에 값을 띄워줌

String result = Double.toString(calculate(inputSpace.getText()));

inputSpace.setText("" + result);

num = "";

//나버지 버튼은 눌렀을 때 계산식에 추가됨

} else {

inputSpace.setText(inputSpace.getText() + e.getActionCommand());

}

}

}

private void fullTextParsing(String inputText) {

equation.clear();

//계산식의 글자를 하나하나 거쳐감

for (int i = 0; i < inputText.length(); i++) {

char ch = inputText.charAt(i);

//연산기호가 나오면 ArrayList에 추가되고 초기화

if (ch == '-' || ch == '+' || ch == '×' || ch == '÷') {

//연산기호를 만났다 : 앞은 숫자라는 것을 의미

//숫자를 ArrayList에 추가

equation.add(num);

//num 초기화

num = "";

//연산기호를 ArrayList에 추가

equation.add(ch + "");

} else {

//나머지는 그냥 숫자 처리

num = num + ch;

}

}

//반복문 끝나고 남아있는 숫자값 추가

equation.add(num);

equation.remove("");

}

//계산 기능

public double calculate(String inputText) {

fullTextParsing(inputText);

//위의 메소드를 실행하면 ArrayList에 숫자와 연산 기호가 담김

double prev = 0;

double current = 0;

//연산 기호에 대한 처리를 위한 변수

String mode = "";

//+일경우 add, -일경우 sub, x일경우 mul, /일경우 div

for (String s : equation) {

if (s.equals("+")) {

mode = "add";

} else if (s.equals("-")) {

mode = "sub";

}  

else if (s.equals("×")) {

mode = "mul";

}  

else if (s.equals("÷")) {

mode = "div";

}  else {

//숫자일 경우 문자열을 Double로 형변환

current = Double.parseDouble(s);

//mode값에 따라 처리, prev는 계속 계산값이 갱신됨

if (mode.equals("add")) {

prev += current;

} else if (mode.equals("sub")) {

prev -= current;

} 

else if (mode.equals("mul")) {

prev *= current;

} 

else if (mode.equals("div")) {

prev /= current;

} else {

prev = current;

}

}

}

//계산값 prev 반환

return prev;

}

public static void main(String args[]) {

new NCalculator();

}

}