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私はホテル予約システムを作成するために作成していますが、私はプロジェクトを実行しています。 "スレッドで例外を受け取りました" AWT-EventQueue- 0 "java.lang.NullPointerException" と私はなぜ見つけることができませんでした。ここ は私が"スレッド内の例外"の理由AWT-EventQueue-0 "java.lang.NullPointerException"
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at hotelreservation.Reservation.fill(Reservation.java:389) at hotelreservation.Reservation.fill(Reservation.java:389)
at hotelreservation.Reservation.<init>(Reservation.java:31)
at hotelreservation.main.jMenuItem1ActionPerformed(main.java:502)
at hotelreservation.main.access$600(main.java:29)
at hotelreservation.main$6.actionPerformed(main.java:277)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6535)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6300)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4891)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2750)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
を受け取ると、ここでのクラスがあり、エラーレポートです
package hotelreservation;
import java.awt.event.KeyEvent;
//import java.sql.Date;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Vector;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;
import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**あなたはSQLクエリのspace直後を逃したように見えます
*
* @author TOSHIBA
*/
public class Reservation extends javax.swing.JInternalFrame {
/**
* Creates new form Reservation
*/
public Reservation() {
initComponents();
fill();
//idgenerate();
username();
Date date = new Date();
txt_date.setDate(date);
}
public void username() {
dbconnection db = new dbconnection();
try {
db.connect();
db.stm = db.con.createStatement();
db.rs = db.stm.executeQuery("select User_name from Users where Status='Active'");
while (db.rs.next()) {
txt_user.setText(db.rs.getString(1));
}
} catch (SQLException e) {
JOptionPane.showMessageDialog(this, e.toString());
}
}
public void idgenerate() {
dbconnection db = new dbconnection();
int IDincrement = 0;
try {
db.connect();
db.stm = db.con.createStatement();
db.rs = db.stm.executeQuery("select MAX(Res_ID)from Reservation");
while(db.rs.next()) {
if (db.rs.first() == false) {
txt_id.setText("Res000001");
} else {
db.rs.last();
int autoID = db.rs.getInt(1) + 1;
String no = String.valueOf(autoID);
int nolong = no.length();
for (int a = 0; a < 3 - nolong; a++) {
no = "0" + no;
}
txt_id.setText("Res" + no);
}
/* db.rs.next();
if (db.rs != null) {
IDincrement = db.rs.getInt(1) + 1;
IDincrement++;
} else {
IDincrement = 1;
}
txt_id.setText("CS" + IDincrement);*/
}
} catch (SQLException e) {
JOptionPane.showMessageDialog(this,"Error \n"+ e.getMessage(),"warning",JOptionPane.WARNING_MESSAGE);
}
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
jPanel3 = new javax.swing.JPanel();
jButton4 = new javax.swing.JButton();
jButton1 = new javax.swing.JButton();
txt_user = new javax.swing.JTextField();
txt_date = new com.toedter.calendar.JDateChooser();
jLabel6 = new javax.swing.JLabel();
jLabel9 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
txt_rrate = new javax.swing.JTextField();
txt_rid = new javax.swing.JTextField();
jLabel4 = new javax.swing.JLabel();
txt_id = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel7 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
txtlname = new javax.swing.JTextField();
txt_fname = new javax.swing.JTextField();
txt_tel = new javax.swing.JTextField();
filler1 = new javax.swing.Box.Filler(new java.awt.Dimension(0, 0), new java.awt.Dimension(0, 0), new java.awt.Dimension(0, 0));
jPanel2 = new javax.swing.JPanel();
jLabel8 = new javax.swing.JLabel();
setBackground(new java.awt.Color(204, 204, 204));
setClosable(true);
setTitle("Reservation Form");
setFont(new java.awt.Font("Arial", 1, 14)); // NOI18N
setFrameIcon(new javax.swing.ImageIcon(getClass().getResource("/images/Icon-Edit-Reservations1.png"))); // NOI18N
setName(""); // NOI18N
setVisible(false);
jPanel1.setBackground(new java.awt.Color(255, 204, 51));
jPanel1.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.LOWERED, java.awt.Color.black, new java.awt.Color(204, 255, 0), java.awt.Color.red, java.awt.Color.black));
jScrollPane1.setBackground(new java.awt.Color(255, 204, 51));
jScrollPane1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "Available Rooms", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Tahoma", 0, 18), new java.awt.Color(204, 0, 204))); // NOI18N
jScrollPane1.setViewportBorder(javax.swing.BorderFactory.createEtchedBorder(javax.swing.border.EtchedBorder.RAISED, null, java.awt.Color.lightGray));
jScrollPane1.setAutoscrolls(true);
jTable1.setBackground(new java.awt.Color(153, 0, 153));
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null, null},
{null, null, null, null},
{null, null, null, null},
{null, null, null, null}
},
new String [] {
"Room_ID", "Room_Type", "Room_rate", "Status"
}
));
jTable1.setToolTipText("click on the row you want ");
jTable1.setGridColor(new java.awt.Color(255, 255, 255));
jTable1.setSelectionBackground(new java.awt.Color(102, 255, 0));
jTable1.setSelectionForeground(new java.awt.Color(255, 0, 51));
jTable1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jTable1MouseClicked(evt);
}
});
jScrollPane1.setViewportView(jTable1);
jPanel3.setBackground(new java.awt.Color(255, 204, 51));
jPanel3.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.LOWERED, new java.awt.Color(204, 0, 204), new java.awt.Color(204, 0, 204), new java.awt.Color(204, 0, 204), new java.awt.Color(204, 0, 204)));
jButton4.setBackground(new java.awt.Color(204, 0, 204));
jButton4.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/sav.png"))); // NOI18N
jButton4.setText("Reserve");
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton4ActionPerformed(evt);
}
});
jButton1.setBackground(new java.awt.Color(204, 0, 204));
jButton1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/Clear-icon.png"))); // NOI18N
jButton1.setText("Clear");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
txt_user.setEditable(false);
txt_date.setDateFormatString("yyyy MMM d");
txt_date.setEnabled(false);
jLabel6.setText("Date_In");
jLabel9.setText("User_name");
jLabel5.setText("Room_Rate:");
txt_rrate.setEditable(false);
txt_rrate.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
txt_rrateActionPerformed(evt);
}
});
txt_rrate.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
txt_rrateKeyPressed(evt);
}
});
txt_rid.setEditable(false);
jLabel4.setText("Room_ID:");
jLabel1.setText("Res_ID:");
jLabel2.setText("Firstname:");
jLabel7.setText("Lastname");
jLabel3.setText("Telephone:");
txtlname.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
txtlnameKeyTyped(evt);
}
});
txt_fname.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
txt_fnameKeyTyped(evt);
}
});
txt_tel.setToolTipText(" valid number format +252615178484");
txt_tel.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
txt_telKeyTyped(evt);
}
});
javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addGap(18, 18, 18)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 110, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 123, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(175, 175, 175))
.addGroup(jPanel3Layout.createSequentialGroup()
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jLabel7)
.addComponent(jLabel3))
.addGap(24, 24, 24)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(txtlname, javax.swing.GroupLayout.DEFAULT_SIZE, 175, Short.MAX_VALUE)
.addComponent(txt_id)
.addComponent(txt_fname)
.addComponent(txt_tel)))
.addComponent(jLabel1))
.addGap(18, 18, 18)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel4)
.addComponent(jLabel6)
.addComponent(jLabel9))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(txt_rid)
.addComponent(txt_date, javax.swing.GroupLayout.DEFAULT_SIZE, 155, Short.MAX_VALUE)
.addComponent(txt_rrate)
.addComponent(txt_user))))
.addContainerGap(43, Short.MAX_VALUE))
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel3Layout.createSequentialGroup()
.addContainerGap(40, Short.MAX_VALUE)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(txt_id, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1)
.addComponent(txt_rid, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel4))
.addGap(18, 18, 18)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(txt_fname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2)
.addComponent(txt_rrate, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel5))
.addGap(18, 18, 18)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(txtlname, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel7)
.addComponent(jLabel6))
.addComponent(txt_date, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(jLabel9)
.addComponent(txt_tel, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(txt_user, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(30, 30, 30)
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap())
);
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 0, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 216, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(24, Short.MAX_VALUE))
);
jPanel2.setBackground(new java.awt.Color(153, 0, 153));
jLabel8.setFont(new java.awt.Font("Tw Cen MT", 1, 48)); // NOI18N
jLabel8.setForeground(new java.awt.Color(255, 255, 255));
jLabel8.setText("Guest Reservation");
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(283, 283, 283)
.addComponent(jLabel8)
.addContainerGap(305, Short.MAX_VALUE))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel8)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, 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(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, 7, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(161, 161, 161))
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(filler1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
);
pack();
}// </editor-fold>
private void txt_rrateActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
public void fill() {
dbconnection db = new dbconnection();
try {
db.connect();
db.stm = db.con.createStatement();
db.rs = db.stm.executeQuery("select Room_ID,Room_type,Room_Rate,Status from Rooms where Status='Available'ORDER By Room_ID");
ResultSetMetaData rmetadata = db.rs.getMetaData();
int columns = rmetadata.getColumnCount();
DefaultTableModel dtm = new DefaultTableModel();
Vector columns_name = new Vector();
Vector data_rows = new Vector();
for (int i = 1; i <= columns; i++) {
columns_name.addElement(rmetadata.getColumnName(i));
}
dtm.setColumnIdentifiers(columns_name);
// dtm.setColumnIdentifiers(Columns_name);
while (db.rs.next()) {
data_rows = new Vector();
for (int j = 1; j <= columns; j++) {
data_rows.addElement(db.rs.getString(j));
}
dtm.addRow(data_rows);
}
jTable1.setModel(dtm);
} catch (SQLException e) {
JOptionPane.showMessageDialog(this, e.getMessage());
}
}
明らかに明白な点はありません。私たちはそれについて「重複した」質問を持っています。 – GhostCat
あなたはヌルオブジェクトで呼び出している何かを見ることができます –
@AbdikairØmärMøhãmûdあなたは389 – Quartal