Java 创建表时,JFrame中的组件不会出现
我是java编程新手。一切进展顺利。但是,每当在JScrollPane中调用创建Jtable时,我的jframe中似乎有一个问题。有时,所有组件(如按钮、标签等)都不会出现。但当我对表及其属性进行注释时,会出现组件。我有什么问题?非常感谢你的帮助。谢谢!下面是我创建表的方法。再次感谢Java 创建表时,JFrame中的组件不会出现,java,swing,jtable,Java,Swing,Jtable,我是java编程新手。一切进展顺利。但是,每当在JScrollPane中调用创建Jtable时,我的jframe中似乎有一个问题。有时,所有组件(如按钮、标签等)都不会出现。但当我对表及其属性进行注释时,会出现组件。我有什么问题?非常感谢你的帮助。谢谢!下面是我创建表的方法。再次感谢 package myphonebookbeta; import java.awt.event.*; import java.sql.*; import java.util.ArrayList; import ja
package myphonebookbeta;
import java.awt.event.*;
import java.sql.*;
import java.util.ArrayList;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class MainForm extends JFrame implements ActionListener{
//<editor-fold defaultstate="collpased" desc="my components">
JFrame f=new JFrame();
JPanel p=new JPanel(null);
JLabel fnameLbl,lnameLbl,addressLbl,cpLbl;
JTextField fname,lname,address,cp;
JButton save,delete,cancel,update;
JTable table=null;
JScrollPane scrollPane=null;
JDesktopPane dp=null;
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc="sql variabled">
private final String url="jdbc:mysql://localhost:3306/";
private final String db="dbnetbeans";
private final String uid="root";
private final String pwd="";
private final String driver="com.mysql.jdbc.Driver";
private Connection con=null;
private Statement st=null;
private ResultSet rs;
private ResultSetMetaData md;
private String sql;
//</editor-fold>
public MainForm(){
mainFormGui();
}//end MainForm
private void mainFormGui(){
f.setTitle("My Phonebook Beta");
f.setSize(600,400);
f.setLocationRelativeTo(f);
f.setVisible(true);
f.setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
f.addWindowListener(new WindowAdapter(){
@Override
public void windowClosing(WindowEvent e){
int cls=JOptionPane.showOptionDialog(null,"You are about to exit the program! Do you wish to proceed?","WARNING",
JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null,null,null);
if (cls==0){
System.exit(0);
}
}
});
initComponents();
}//end of mainFormGui
private void initComponents(){
//<editor-fold defaultstate="collapsed" desc="components declaration">
fnameLbl=new JLabel("First Name : "); fnameLbl.setBounds(10,18,90,24);
lnameLbl=new JLabel("Last Name : "); lnameLbl.setBounds(10,52,90,24);
addressLbl=new JLabel("Address : "); addressLbl.setBounds(10,86,90,24);
cpLbl=new JLabel("Contact No. :"); cpLbl.setBounds(10,120,90,24);
fname=new JTextField(""); fname.setBounds(100,14,140,24);
lname=new JTextField(""); lname.setBounds(100,48,140,24);
address=new JTextField(""); address.setBounds(100,82,140,24);
cp=new JTextField(""); cp.setBounds(100,116,140,24);
save=new JButton("SAVE"); save.setBounds(10,150,110,24);
cancel=new JButton("Cancel"); cancel.setBounds(130,150,110,24);
update=new JButton("Update"); update.setBounds(10,180,110,24);
delete=new JButton("Delete"); delete.setBounds(130,180,110,24);
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc="adding to panel">
p.setVisible(true);
p.add(fnameLbl); p.add(fname);
p.add(lnameLbl); p.add(lname);
p.add(addressLbl); p.add(address);
p.add(cpLbl); p.add(cp);
p.add(save);p.add(delete); p.add(update); p.add(cancel);
//</editor-fold>
btnAction();
包装myphonebookbeta;
导入java.awt.event.*;
导入java.sql.*;
导入java.util.ArrayList;
导入java.util.Vector;
导入java.util.logging.Level;
导入java.util.logging.Logger;
导入javax.swing.*;
导入javax.swing.table.DefaultTableModel;
公共类MainForm扩展JFrame实现ActionListener{
//
JFrame f=新的JFrame();
JPanel p=新的JPanel(空);
JLabel fnameLbl、lnameLbl、addressLbl、cpLbl;
JTextField fname,lname,address,cp;
JButton保存、删除、取消、更新;
JTable table=null;
JScrollPane scrollPane=null;
JDesktopPane dp=null;
//
//
私有最终字符串url=“jdbc:mysql://localhost:3306/";
私有最终字符串db=“dbnetbeans”;
私有最终字符串uid=“root”;
私有最终字符串pwd=“”;
私有最终字符串driver=“com.mysql.jdbc.driver”;
私有连接con=null;
私有语句st=null;
私人结果集;
私有结果元数据md;
私有字符串sql;
//
公共表格({
mainFormGui();
}//尾端主窗体
私有void mainFormGui(){
f、 setTitle(“我的电话簿测试版”);
f、 设置大小(600400);
f、 设置相对位置(f);
f、 setVisible(真);
f、 setDefaultCloseOperation(关闭时不执行任何操作);
f、 addWindowListener(新的WindowAdapter(){
@凌驾
公共无效窗口关闭(WindowEvent e){
int cls=JOptionPane.showOptionDialog(null,“您即将退出程序!是否继续?”,“警告”,
JOptionPane.YES\u NO\u选项,JOptionPane.WARNING\u消息,null,null,null);
如果(cls==0){
系统出口(0);
}
}
});
初始化组件();
}//mainFormGui结束
私有组件(){
//
fnameLbl=新的JLabel(“名字:”);fnameLbl.setBounds(10,18,90,24);
lnameLbl=新的JLabel(“姓氏:”);lnameLbl.setBounds(10,52,90,24);
addressLbl=新的JLabel(“地址:”;addressLbl.setBounds(10,86,90,24);
cpLbl=新的JLabel(“联系电话:”);cpLbl.立根(10120,90,24);
fname=newjtextfield(“”);fname.setBounds(100,14140,24);
lname=新的JTextField(“”);lname.setBounds(100,48140,24);
地址=新的JTextField(“”);地址.setBounds(100,82140,24);
cp=新的JTextField(“”);cp.setBounds(100116140,24);
save=newjbutton(“save”);save.setBounds(10150110,24);
cancel=新的JButton(“cancel”);cancel.setBounds(130150110,24);
update=newjbutton(“update”);update.setBounds(10180110,24);
delete=newjbutton(“delete”);delete.setBounds(130180110,24);
//
//
p、 setVisible(真);
p、 添加(fnameLbl);p.add(fname);
p、 添加(lnameLbl);p.add(lname);
p、 添加(地址LBL);p.add(地址);
p、 添加(cpLbl);p.add(cp);
p、 添加(保存);添加(删除);添加(更新);添加(取消);
//
b动作();
//createTable()
f.add(p);
}//初始化组件结束
私有无效btnAction(){
cancel.addActionListener(此);
save.addActionListener(这个);
delete.addActionListener(这个);
}//端隙
@凌驾
已执行的公共无效行动(行动事件ae){
字符串fn=fname.getText();
字符串ln=lname.getText();
String ad=address.getText();
字符串cpn=cp.getText();
试一试{
//
如果(ae.getSource()=取消){
clearFields();
}//结束取消
//
//
如果(ae.getSource()==保存){
sql=“插入tbphonebook(名字、姓氏、地址、cp)”
+“值(“+fn+”、“+ln+”、“+ad+”、“+cpn+”)”;
connect();
st=con.createStatement();
st.executeUpdate(sql);
断开连接();
JOptionPane.showMessageDialog(null,“信息成功保存!”,“确认-保存”,JOptionPane.INFORMATION\u消息);
clearFields();
}//结束保存
//
//
如果(ae.getSource()==删除){
int ch=JOptionPane.showOptionDialog(null,“此操作不可撤销。是否继续?”,
“是否删除此联系人?”,JOptionPane。是\否选项,JOptionPane。警告消息,null,null,null);
如果(ch==0){
sql=“从tbphonebook中删除,其中名字类似于“'+fn+”,姓氏类似于“'+ln+”;
connect();
st=con.createStatement();
st.executeUpdate(sql);
断开连接();
JOptionPane.showMessageDialog(null,“联系人已成功删除!”,“确认-删除”,JOptionPane.INFORMATION\u消息);
clearFields();
}//如果(ch==0)结束
}//结束删除
//
}//试一试
捕获(例外e){
e、 printStackTrace();
}//抓住
}//已执行的结束操作
专用void connect(){
试一试{
Class.forName(driver.newInstance();
con=DriverManager.getConnection(url+db、uid、pwd);
}
捕获(例外情况除外){
例如printStackTrace();
}
}//端接
私有无效断开连接(){
试一试{
con.close();
}
捕获(例外情况除外){
例如printStackTrace();
}
}//端部断开
私有void clearFields(){
fname.setText(“”);
lname.setText(“”);
地址:setText(“”);
cp.setText(“”);
fname.requestFocus();
}//结束clearField
私有void createTable(){
scrollPane=newJScrollPane(this.table);
滚动窗格.立根(250,14320160);
scrollPane.setVisible(true);
scrollPane.setViewportView(表);
p、 添加(滚动窗格);
}//结束创建表
私有void fillTable()引发SQLException{
ArrayList colNames=新的ArrayList();
ArrayList数据=新的ArrayList();
ArrayList行=新数组
f.add(p);
}//end of initComponents
private void btnAction(){
cancel.addActionListener(this);
save.addActionListener(this);
delete.addActionListener(this);
}//end void btnAction
@Override
public void actionPerformed(ActionEvent ae){
String fn=fname.getText();
String ln=lname.getText();
String ad=address.getText();
String cpn=cp.getText();
try{
//<editor-fold defaultstate="collapsed" desc="cancel_click">
if(ae.getSource()==cancel){
clearFields();
}//end cancel
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc="save_click">
if(ae.getSource()==save){
sql="Insert into tbphonebook (firstname,lastname,address,cp)"
+ " value('"+fn+"','"+ln+"','"+ad+"','"+cpn+"')";
connect();
st=con.createStatement();
st.executeUpdate(sql);
disconnect();
JOptionPane.showMessageDialog(null,"Info successfully SAVED!","confirmation - SAVE ", JOptionPane.INFORMATION_MESSAGE);
clearFields();
}//end save
//</editor-fold>
//<editor-fold defaultstate="collapsed" desc="delete_click">
if(ae.getSource()==delete){
int ch=JOptionPane.showOptionDialog(null,"This action is irrevocable. Do you wish tocontinue?",
"Delete this contact?",JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null,null,null);
if (ch==0){
sql="delete from tbphonebook where firstname like '"+fn+"' and lastname like '"+ln+"'";
connect();
st=con.createStatement();
st.executeUpdate(sql);
disconnect();
JOptionPane.showMessageDialog(null,"Contact successfully DELETED!","confirmation - DELETE ", JOptionPane.INFORMATION_MESSAGE);
clearFields();
}//end if(ch==0)
}//end delete
//</editor-fold>
}//try
catch(Exception e){
e.printStackTrace();
}//catch
}//end actionPerformed
private void connect(){
try{
Class.forName(driver).newInstance();
con=DriverManager.getConnection(url+db,uid,pwd);
}
catch(Exception ex){
ex.printStackTrace();
}
}//end connect
private void disconnect(){
try{
con.close();
}
catch(Exception ex){
ex.printStackTrace();
}
}//end disconnect
private void clearFields(){
fname.setText("");
lname.setText("");
address.setText("");
cp.setText("");
fname.requestFocus();
}//end clearField
private void createTable(){
scrollPane=new JScrollPane(this.table);
scrollPane.setBounds(250,14,320,160);
scrollPane.setVisible(true);
scrollPane.setViewportView(table);
p.add(scrollPane);
}//end createTable
private void fillTable() throws SQLException{
ArrayList colNames=new ArrayList();
ArrayList data=new ArrayList();
ArrayList row=new ArrayList();
sql="select * from tbphonebook";
connect();
st=con.createStatement();
rs = st.executeQuery(sql);
try{
md =rs.getMetaData();
int col=md.getColumnCount();
//to getcolumn names
for (int i=1;1<=col;i++){
colNames.add(md.getColumnName(i));
}
//to get row data
while(rs.next()){
for(int i=1;1<=col;i++){
row.add(rs.getObject(i));
}
data.add(row);
}
}
catch(Exception ex){
ex.printStackTrace();
}
}//end fillTable
}
JPanel p=new JPanel(null);