10 個の if ステートメントと if else ステートメントで実行されるアクションがあり、私の JTextField には 1 つだけ表示され、それらをスタックして 1 桁以上の数字を作成する方法が表示されます。
すべてのコードを読む人は必要ありません。actionPerformed の int をスタックしたいだけです。
私は基本的なGUI電卓を作っています。
    @Override
public void actionPerformed(ActionEvent e) {
    if(e.getSource().equals(oneButton)){
        input1 = 1;
        text.setText(""+input);}
    else if (e.getSource().equals(twoButton)){
        input2 = 2;
        text.setText(""+input);}
    else if(e.getSource().equals(threeButton)){
        input3 = 3;
        text.setText(""+input);}
    else if(e.getSource().equals(fourButton)){
        input4 = 4;
        text.setText(""+input);}
    else if(e.getSource().equals(fiveButton)){
        input5 = 5;
        text.setText(""+input);}
    else if(e.getSource().equals(sixButton)){
        input6 = 6;
        text.setText(""+input);}
    else if(e.getSource().equals(sevenButton)){
        input7 = 7;
        text.setText(""+input);}
    else if(e.getSource().equals(eightButton)){
        input8 = 8;
        text.setText(""+input);}
    else if(e.getSource().equals(nineButton)){
        input9 = 9;
        text.setText(""+input);}
    else if(e.getSource().equals(zeroButton)){
        input0 = 0;
        text.setText(""+input);}
}
私のコードの残りの部分
//imports
public class Ken implements ActionListener{
static JButton oneButton = new JButton("1");
static JButton twoButton = new JButton("2");
static JButton threeButton = new JButton("3");
static JButton fourButton = new JButton("4");
static JButton fiveButton = new JButton("5");
static JButton sixButton = new JButton("6");
static JButton sevenButton = new JButton("7");
static JButton eightButton = new JButton("8");
static JButton nineButton = new JButton("9");
static JButton zeroButton = new JButton("0");
static JButton minusButton = new JButton("-");
static JButton timesButton = new JButton("*");
static JButton enterButton = new JButton("=");
static JButton dividButton = new JButton("/");
static JButton plusButton = new JButton("+");
public static int input;
public static int input1;
public static int input2;   
public static int input3;
public static int input4;
public static int input5;
public static int input6;
public static int input7;
public static int input8;
public static int input9;
public static int input0;
public static JTextField text = new JTextField("0", 9);
public Ken(){
    JFrame frame = new JFrame("MyCalc");
    frame.setSize(476, 500);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
    frame.setResizable(false);
    FlowLayout fl = new FlowLayout(0, 30, 20);
    setLayout(fl);
    Border empty;
    empty = BorderFactory.createEmptyBorder();
    frame.getContentPane().setLayout(fl);
    Container con = frame.getContentPane();
    con.setBackground(Color.LIGHT_GRAY);
    Font f = new Font("MS UI Gothic", Font.BOLD, 40);
    Font f2 = new Font("Engravers MT", Font.PLAIN, 40);
    int bHeight = 80;
    int bWidth = 70;
    text.setBackground(Color.GREEN);
    text.setFont(f2);
    text.setPreferredSize(new Dimension(bHeight, bWidth));
    text.setEditable(false);
    frame.add(text, BorderLayout.NORTH);
    oneButton.setPreferredSize(new Dimension(bHeight, bWidth));
    oneButton.setBackground(Color.DARK_GRAY);
    oneButton.setForeground(Color.GREEN);
    oneButton.setFont(f);
    oneButton.addActionListener(this);
    frame.add(oneButton);
    twoButton.setPreferredSize(new Dimension(bHeight, bWidth));
    twoButton.setBackground(Color.DARK_GRAY);
    twoButton.setForeground(Color.GREEN);
    twoButton.setFont(f);
    twoButton.addActionListener(this);
    frame.add(twoButton);
    threeButton.setPreferredSize(new Dimension(bHeight, bWidth));
    threeButton.setBackground(Color.DARK_GRAY);
    threeButton.setForeground(Color.GREEN);
    threeButton.setFont(f);
    threeButton.addActionListener(this);
    frame.add(threeButton);
    plusButton.setPreferredSize(new Dimension(bHeight, bWidth));
    plusButton.setBackground(Color.DARK_GRAY);
    plusButton.setForeground(Color.GREEN);
    plusButton.setFont(f);
    plusButton.addActionListener(this);
    frame.add(plusButton);
    fourButton.setPreferredSize(new Dimension(bHeight, bWidth));
    fourButton.setBackground(Color.DARK_GRAY);
    fourButton.setForeground(Color.GREEN);
    fourButton.setFont(f);
    fourButton.addActionListener(this);
    frame.add(fourButton);
    fiveButton.setPreferredSize(new Dimension(bHeight, bWidth));
    fiveButton.setBackground(Color.DARK_GRAY);
    fiveButton.setForeground(Color.GREEN);
    fiveButton.setFont(f);
    fiveButton.addActionListener(this);
    frame.add(fiveButton);
    sixButton.setPreferredSize(new Dimension(bHeight, bWidth));
    sixButton.setBackground(Color.DARK_GRAY);
    sixButton.setForeground(Color.GREEN);
    sixButton.setFont(f);
    sixButton.addActionListener(this);
    frame.add(sixButton);
    minusButton.setPreferredSize(new Dimension(bHeight, bWidth));
    minusButton.setBackground(Color.DARK_GRAY);
    minusButton.setForeground(Color.GREEN);
    minusButton.setFont(f);
    minusButton.addActionListener(this);
    frame.add(minusButton);
    sevenButton.setPreferredSize(new Dimension(bHeight, bWidth));
    sevenButton.setBackground(Color.DARK_GRAY);
    sevenButton.setForeground(Color.GREEN);
    sevenButton.setFont(f);
    sevenButton.addActionListener(this);
    frame.add(sevenButton);
    eightButton.setPreferredSize(new Dimension(bHeight, bWidth));
    eightButton.setBackground(Color.DARK_GRAY);
    eightButton.setForeground(Color.GREEN);
    eightButton.setFont(f);
    eightButton.addActionListener(this);
    frame.add(eightButton);
    nineButton.setPreferredSize(new Dimension(bHeight,bWidth));
    nineButton.setBackground(Color.DARK_GRAY);
    nineButton.setForeground(Color.GREEN);
    nineButton.setFont(f);
    nineButton.addActionListener(this);
    frame.add(nineButton);
    timesButton.setPreferredSize(new Dimension(bHeight, bWidth));
    timesButton.setBackground(Color.DARK_GRAY);
    timesButton.setForeground(Color.GREEN);
    timesButton.setFont(f);
    timesButton.addActionListener(this);
    frame.add(timesButton);
    zeroButton.setPreferredSize(new Dimension(bHeight, bWidth));
    zeroButton.setBackground(Color.DARK_GRAY);
    zeroButton.setForeground(Color.GREEN);
    zeroButton.setFont(f);
    zeroButton.addActionListener(this);
    frame.add(zeroButton);
    enterButton.setPreferredSize(new Dimension(190, bWidth));
    enterButton.setBackground(Color.DARK_GRAY);
    enterButton.setForeground(Color.GREEN);
    enterButton.setFont(f);
    enterButton.addActionListener(this);
    frame.add(enterButton);
    dividButton.setPreferredSize(new Dimension(bHeight, bWidth));
    dividButton.setBackground(Color.DARK_GRAY);
    dividButton.setForeground(Color.GREEN);
    dividButton.setFont(f);
    dividButton.addActionListener(this);
    frame.add(dividButton);
    frame.setComponentOrientation(
            ComponentOrientation.LEFT_TO_RIGHT);
}
private static Dimension Dimension(int bHeight, int bWidth) {
    // TODO Auto-generated method stub
    return null;
}
private static void setLayout(FlowLayout fl) {
    // TODO Auto-generated method stub
}
public static void main(String[] args){
    new Ken();
}
@Override
public void actionPerformed(ActionEvent e) {
    if(e.getSource().equals(oneButton)){
        input1 = 1;
        text.setText(""+input);}
    else if (e.getSource().equals(twoButton)){
        input2 = 2;
        text.setText(""+input);}
    else if(e.getSource().equals(threeButton)){
        input3 = 3;
        text.setText(""+input);}
    else if(e.getSource().equals(fourButton)){
        input4 = 4;
        text.setText(""+input);}
    else if(e.getSource().equals(fiveButton)){
        input5 = 5;
        text.setText(""+input);}
    else if(e.getSource().equals(sixButton)){
        input6 = 6;
        text.setText(""+input);}
    else if(e.getSource().equals(sevenButton)){
        input7 = 7;
        text.setText(""+input);}
    else if(e.getSource().equals(eightButton)){
        input8 = 8;
        text.setText(""+input);}
    else if(e.getSource().equals(nineButton)){
        input9 = 9;
        text.setText(""+input);}
    else if(e.getSource().equals(zeroButton)){
        input0 = 0;
        text.setText(""+input);}
}
}