java - 使用 jfilechooser 选择文件挂起程序

Question

我想从硬盘中选择一个包含矩阵的文件......并且我想将其保存在二维数组中......但是每当我选择该文件时，我的应用程序就会挂起并且我无法按任何其他按钮

这是我的示例:

public class Flood extends javax.swing.JFrame {

/**
 * Creates new form NewJFrame
 */
public static int[][] multi;
public Flood() {
    initComponents();
    browseB.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent ae) {
            JFileChooser fc = new JFileChooser();
            switch (fc.showOpenDialog(null)) {
                case JFileChooser.APPROVE_OPTION:
                    File file = fc.getSelectedFile();

                        Scanner input = null;
            try {
                input = new Scanner(file);
            } catch (FileNotFoundException ex) {
                Logger.getLogger(Flood.class.getName()).log(Level.SEVERE, null, ex);
            }
                        int row = 0;
    int col = 0;
    while (input.hasNextLine()) {
        ++row;
        Scanner colReader = new Scanner(input.nextLine());
        while (colReader.hasNextInt()) {
            ++col;
        }
    }

    multi = new int[row][col];

    input.close();

            {
                try {
                    input = new Scanner(file);
                } catch (FileNotFoundException ex) {
                    Logger.getLogger(Flood.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
    for (int i = 0; i < row; ++i) {
        for (int j = 0; j < col; ++j) {
            if (input.hasNextInt()) {
                multi[i][j] = input.nextInt();

            }
        }
    }

                    break;
            }

        }
    });
    jButton1.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent ae) {
           for(int i=0;i<multi.length;i++)
            {
            for(int j=0;j<multi[0].length;j++)
            {
                System.out.println(""+multi[i][j]);
            }
            }
               }
    });
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
 private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    browseTF = new javax.swing.JTextField();
    browseB = new javax.swing.JButton();
    jLabel1 = new javax.swing.JLabel();
    jLabel2 = new javax.swing.JLabel();
    jLabel3 = new javax.swing.JLabel();
    jLabel4 = new javax.swing.JLabel();
    jButton1 = new javax.swing.JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    browseB.setText("Browse");
    browseB.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            browseBActionPerformed(evt);
        }
    });

    jLabel1.setText("number of 0 :-");

    jLabel2.setText("0");

    jLabel3.setText("number of 1 :-");

    jLabel4.setText("0");

    jButton1.setText("go");

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(42, 42, 42)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addComponent(browseTF, javax.swing.GroupLayout.DEFAULT_SIZE, 256, Short.MAX_VALUE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addComponent(browseB))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                        .addComponent(jLabel3, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(jLabel1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 75, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel4))
                    .addGap(0, 0, Short.MAX_VALUE))))
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(159, 159, 159)
            .addComponent(jButton1)
            .addGap(0, 0, Short.MAX_VALUE))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(28, 28, 28)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(browseTF, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(browseB))
            .addGap(7, 7, 7)
            .addComponent(jButton1)
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jLabel1)
                .addComponent(jLabel2))
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jLabel3))
            .addContainerGap(176, Short.MAX_VALUE))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(24, 24, 24)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(27, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(18, Short.MAX_VALUE))
    );

    pack();
}// </editor-fold>                        

private void browseBActionPerformed(java.awt.event.ActionEvent evt) {                                        

} 


/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(Flood.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(Flood.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(Flood.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(Flood.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new Flood().setVisible(true);
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JButton browseB;
private javax.swing.JTextField browseTF;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JPanel jPanel1;

提前致谢

Answer 1

这里有一个无限循环:

while (colReader.hasNextInt()) {
    ++col;
}

您根本没有推进 colReader 扫描器，因此它永远查看该行上的第一个 int 值。

您可以通过在遇到每个 int 值时移过去来修复它:

while (colReader.hasNextInt()) {
    colReader.nextInt();
    ++col;
}

将来，您可以通过使用调试器检查程序卡在哪里来自行解决此类问题，或者，如果您在命令行上运行，则可以使用 Windows 上的 Ctrl-Break 或 Linux 和 OS X 上的 Ctrl-\ (SIGQUIT) 强制 Java 打印每个 Activity 线程的堆栈跟踪。