Java documentlistener - 程序在输入后停止工作

Question

您好我的documentlistener有问题。 将值插入文本字段后，程序停止工作。该程序应该对具有第二行文本字段的第一行文本字段进行异或，并将结果放入第三行文本字段

package opa.beta1;

import java.awt.BorderLayout;
import java.math.BigInteger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

public class TextFieldEvent {

    JTextField arrayIV[] = new JTextField[8];
    JTextField plaintextArray[] = new JTextField[8];
    JTextField ciphertextArray[] = new JTextField[8];
    JFrame frame = new JFrame("OPA");
    JPanel panel1 = new JPanel();
    JPanel panel2 = new JPanel();
    JPanel panel3 = new JPanel();

    public void setJPanel(JTextField array[], JPanel container, String s) {
        for (int i = 0; i < 8; i++) {
            array[i] = new JTextField(s, 4);
            array[i].getDocument().addDocumentListener(new DocumentListener() {
                @Override
                public void insertUpdate(DocumentEvent de) {
                    setCiphertext();
                }

                @Override
                public void removeUpdate(DocumentEvent de) {
                    setCiphertext();
                }

                @Override
                public void changedUpdate(DocumentEvent de) {
                    setCiphertext();
                }
            });
            container.add(array[i]);
        }
    }

    public String setXORText(JTextField textfield1, JTextField textfield2) {
        String okno1, okno2;
        okno1 = textfield1.getText();
        okno2 = textfield2.getText();
        if (okno1.equals("")) {
            return okno2;
        }
        BigInteger pom1 = new BigInteger(okno1, 16);
        if (okno2.equals("")) {
            return okno1;
        }
        BigInteger pom2 = new BigInteger(okno2, 16);
        BigInteger res = pom1.xor(pom2);
        String s = res.toString(16);
        return s;
    }

    public String setXORText(JTextField pole1[], JTextField pole2[], int i) {

        String okno1 = pole1[i].getText();
        String okno2 = pole2[i].getText();
        if (okno1.equals("")) {
            return pole2[i].getText();
        }
        BigInteger pom1 = new BigInteger(okno1, 16);
        if (okno2.equals("")) {
            return pole1[i].getText();
        }
        BigInteger pom2 = new BigInteger(okno2, 16);
        BigInteger res = pom1.xor(pom2);
        String s = res.toString(16);
        return s;
    }

    public void setCiphertext() {
        //textfield3.setText(setXORText(textfield1, textfield2));
        for (int i = 0; i < 8; i++) {
            ciphertextArray[i].setText(setXORText(arrayIV, plaintextArray, i));
        }
    }

    public TextFieldEvent() {
        setJPanel(arrayIV, panel1, "1a");
        setJPanel(plaintextArray, panel2, "1b");
        setJPanel(ciphertextArray, panel3, "1");

        frame.add(panel1, BorderLayout.NORTH);
        frame.add(panel2, BorderLayout.CENTER);
        frame.add(panel3, BorderLayout.SOUTH);

        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
        frame.setSize(675, 275);
        frame.setResizable(false);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new TextFieldEvent();
            }
        });

    }
}

堆栈跟踪

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Attempt to mutate in notification at javax.swing.text.AbstractDocument.writeLock(AbstractDocument.java:1338) at javax.swing.text.AbstractDocument.replace(AbstractDocument.java:659) at javax.swing.text.JTextComponent.setText(JTextComponent.java:1718) at opa.beta1.TextFieldEvent.setCiphertext(TextFieldEvent.java:82) at opa.beta1.TextFieldEvent$1.removeUpdate(TextFieldEvent.java:33)

Answer 1

将setCiphertext();包裹在SwingUtilities.invokeLater

中的DocumentListener中

Answer 2

这一行

setJPanel(ciphertextArray, panel3, "1");

还会为DocumentListener ciphertextArray的每个元素添加TextField。因此，每当其中一个密文TextField的值发生更改时，都会调用方法setCipherText()。

这导致以下顺序：

1. 您在TextField或arrayIV
的plainTextArray之一中输入新值
2. setCipherText()已被调用
3. setCipherText()更改密文TextField
的值 再次调用
4. setCipherText()（上面的解释）。回到2。

这就是为什么你得到IllegalStateException。

所以解决方案是不要在DocumentListener的{​​{1}}中添加TextFields。

解决方案可以按如下方式实施：

ciphertextArray