Java swing jcombobox中的意外输出getSelectedIndex方法
我正在使用swing中的jcombobox，并从getSelectedIndex方法中获得一些意外的输出。当我选择第一个JComboBox时，第二个combobox被启用，我使用的方法是getSelectedIndex（），它显示了一些意外的输出。我的意思是它应该显示“0”，但它显示的是“0”，然后是“-1”，然后是异常，最后是“0”。我无法找出异常的原因。我在这里只展示了部分代码希望你们能抓住我Java swing jcombobox中的意外输出getSelectedIndex方法,java,swing,jcombobox,Java,Swing,Jcombobox,我正在使用swing中的jcombobox，并从getSelectedIndex方法中获得一些意外的输出。当我选择第一个JComboBox时，第二个combobox被启用，我使用的方法是getSelectedIndex（），它显示了一些意外的输出。我的意思是它应该显示“0”，但它显示的是“0”，然后是“-1”，然后是异常，最后是“0”。我无法找出异常的原因。我在这里只展示了部分代码希望你们能抓住我 public Tester() { super("Utility
public Tester() {
super("Utility for publish_date");
Container contentpane = getContentPane();
contentpane.setLayout(new BorderLayout());
try{
conn = new MyConn().getMyConnection();
s = conn.createStatement();
rs = s.executeQuery("select distinct state_name , state_code from state_master where state_code in (select statecode from pdf_detail) order by state_name");
statelist.add(0,"Select state");
while(rs.next())
{
statelist.add(rs.getString(1));
statecodelist.add(rs.getString(2));
}
System.out.println("the content of statelist"+ statelist);
System.out.println("the content of statecodelist"+statecodelist);
list_state = new String [statelist.size()];
statelist.toArray(list_state);
}catch(Exception e)
{
System.out.println(e);
log(e.getMessage());
}
combo = new JComboBox(list_state);
combo.setBounds(50, 50, 100, 20);
combo.addActionListener(this);
combo1 = new JComboBox();
combo1.addActionListener(this);
combo1.setEnabled(true);
combo1.setBounds(50, 100, 100, 20);
combo2 = new JComboBox();
combo2.addActionListener(this);
combo2.setEnabled(true);
combo2.setBounds(50, 100, 100, 20);
JPanel panel1 = new JPanel(new FlowLayout());
panel1.add(combo);
panel1.add(combo1);
panel1.add(combo2);
contentpane.add(panel1 , BorderLayout.NORTH);
label = new JLabel();
label.setText("Choose publish Date by selecting below.");
final SimpleDateFormat dateformater = new SimpleDateFormat("yyyy-MM-dd");
datepicker = new JXDatePicker();
datepicker.setFormats(dateformater);
datepicker.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
//label.setText(datepicker.getDate().toString());
System.out.println("new date is "+dateformater.format(datepicker.getDate()));
publish_date = dateformater.format(datepicker.getDate());
}
});
JPanel panel2 = new JPanel(new FlowLayout());
panel2.add(label);
panel2.add(datepicker);
contentpane.add(panel2 , BorderLayout.CENTER);
pbutton = new JButton("Submit");
pbutton.addActionListener(this);
JPanel panel3 = new JPanel();
panel3.add(pbutton);
contentpane.add(panel3 , BorderLayout.SOUTH);
setSize(600,150);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent a)
{
if (a.getSource() == combo) {
statename = (String)combo.getSelectedItem();
System.out.println("statename======="+statename);
q = combo.getSelectedIndex();
System.out.println("....q....."+q);
System.out.println(",,,,,,,,,,"+statecodelist.get(q-1));
try{
districtcodelist.clear();
ResultSet rs2 =s.executeQuery("select distinct district_name , district_code from district_master where state_code= '"+statecodelist.get(q-1)+"' AND district_code in (select districtcode from pdf_detail where statecode = '"+statecodelist.get(q-1)+"') order by district_name ");
//districtlist.add(0, "Select district");
while(rs2.next())
{
districtlist.add(rs2.getString(1));
districtcodelist.add(rs2.getString(2));
}
System.out.println("the content of districtlist"+ districtlist);
System.out.println("the content of districtcodelist"+districtcodelist);
list_district = new String [districtlist.size()];
districtlist.toArray(list_district);
}catch(Exception f)
{
f.printStackTrace();
System.out.println(f);
log(f.getMessage());
}
//combo1.setEnabled(true);
combo1.removeAllItems();
for (int i = 0; i < list_district.length; i++) {
combo1.removeItem(list_district[i]);
combo1.addItem(list_district[i]);
}
districtlist.clear();
}
else if (a.getSource() == combo1)
{
// System.out.println("combo1");
districtname = (String)combo1.getSelectedItem();
System.out.println("districtname========"+districtname);
w = combo1.getSelectedIndex();
if(w == -1)
{
System.out.println("hre is the prob");
System.out.println(combo1.getSelectedItem());
}
System.out.println(".....w...."+w);
System.out.println(combo1.getSelectedItem());
//System.out.println(",,,,,,,,,,"+districtcodelist.get(w));
try{
//tehsillist.add(0,"Select tehsil");
ResultSet rs3 = s.executeQuery("select distinct tehsil_name , tehsil_code from tehsil_master where state_code= '"+statecodelist.get(q-1)+"' AND district_code='"+districtcodelist.get(w)+"' AND tehsil_code in ( select tehsilcode from pdf_detail where statecode = '"+statecodelist.get(q-1)+"' AND districtcode = '"+districtcodelist.get(w)+"') order by tehsil_name");
while(rs3.next())
{
tehsillist.add(rs3.getString(1));
}
list_tehsil = new String [tehsillist.size()];
tehsillist.toArray(list_tehsil);
}catch(Exception g)
{
g.printStackTrace();
log(g.getMessage());
System.out.println(g);
}
//combo2.setEnabled(true);
combo2.removeAllItems();
for (int i = 0; i < list_tehsil.length; i++) {
combo2.removeItem(list_tehsil[i]);
combo2.addItem(list_tehsil[i]);
}
tehsillist.clear();
}
if(a.getSource() == pbutton){
tehsilname = (String)combo2.getSelectedItem();
e = combo2.getSelectedIndex();
System.out.println("....e....."+e);
System.out.println("....w....."+w);
if((String)combo.getSelectedItem()== "Select state" || (String)combo1.getSelectedItem()== "Select district" || (String)combo2.getSelectedItem()== "Select tehsil" || publish_date == null )
{
JOptionPane.showMessageDialog(this, "Select all four items first.");
}
else
{
int c = JOptionPane.showConfirmDialog(this,"Do you really want to continue?","update publish date?",JOptionPane.YES_NO_OPTION);
if(c==0)
{
log("State is "+statename+" \nDistrict is "+districtname+" \nTehsil is "+tehsilname);
try{
Properties pr =new Properties();
pr.load(new FileInputStream("config/config.properties"));
//String publish_date = pr.getProperty("publish_date");
ResultSet rs4 = s.executeQuery("select publish_date from pdf_detail where statecode = (select state_code from state_master where state_name = '"+statename+"') AND districtcode = (select district_code from district_master where district_name = '"+districtname+"') AND tehsilcode = (select tehsil_code from tehsil_master where tehsil_name = '"+tehsilname+"') ");
while(rs4.next())
{
testvalue = rs4.getString(1);
}
if(testvalue != null)
{
n = JOptionPane.showConfirmDialog(this,"Publish_date is already assigned to this tehsil. Do you want to update it?","update publish date?",JOptionPane.YES_NO_OPTION);
System.out.println("the value of n is "+n);
}
if(testvalue == null || n == 0)
{
JOptionPane.showMessageDialog(this, "Publish_date updated");
s.executeUpdate("Update pdf_detail set publish_date = '"+publish_date+"'where statecode=(select state_code from state_master where state_name='"+statename+"') AND districtcode=(select district_code from district_master where district_name='"+districtname+"') AND tehsilcode=(select tehsil_code from tehsil_master where tehsil_name='"+tehsilname+"')");
log("publish date of "+tehsilname+" is updated from ("+testvalue+") to ("+publish_date+")");
}
}catch(Exception e){
log(e.getMessage());
System.out.println(e);}
if(n==1)
{
JOptionPane.showMessageDialog(this, "Pulish_date updation canceled");
log("publish_date process canceled as it is already done");
}
JOptionPane.showMessageDialog(this, "Proces completed");
log("process completed at");
log("------------------------------------------------------------------------");
excelLog();
}
else{
setVisible(false);
(new Publish_Date()).setVisible(true);
}
}
}
}
public static void main(String args[]) {
log("process start time");
(new Tester()).setVisible(true);
}
尝试ActionListener
JComboBox<String> jb = new JComboBox<String>();
jb.add("Vivek"):
jb.add("Vicky");
jb.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
System.out.println(jb.getSelectedIndex());
}
});
JComboBox jb=newjcombobox（）；
jb.添加（“Vivek”）：
jb.添加（“Vicky”）；
jb.addActionListener（新ActionListener（）{
@凌驾
已执行的公共无效操作（操作事件arg0）{
System.out.println（jb.getSelectedIndex（））；
}
});
combo1.removeAllItems（）删除，这将导致复选框将其选择更改为-1并触发事件
很可能您可以检测到-1值，然后忽略事件或进行一些清理。可以尝试ActionListener。但是你能告诉我ItemListener有什么问题吗？即使我使用ActionListener，也会有同样的问题。这里的一切都可能是暗无天日的，为了更好的帮助，我已经在edit中添加了完整的代码。只是想确保把你的实际代码放在这里没有问题？？？@user1519780如果你可以发布你的代码，那就没有问题了！但是，如果您可以发布一个最小的、可运行的示例，该示例仍然演示了您的问题，那么修复它将更容易：）
JComboBox<String> jb = new JComboBox<String>();
jb.add("Vivek"):
jb.add("Vicky");
jb.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
System.out.println(jb.getSelectedIndex());
}
});