请查看以下代码
DatabaseHandler.java
public List getDetails(String name)
{
List details = new ArrayList();
name = name.replaceAll("\\s+", "").toUpperCase();
try
{
createConnection();
PreparedStatement ps = con.prepareStatement("select * from PhoneData where upper(rtrim(NULLIF(names,''))) || upper(rtrim(NULLIF(middleName,''))) || upper(rtrim(NULLIF(lastName,'')))=?");
ps.setString(1, name);
ResultSet rs = ps.executeQuery();
// System.out.println("First Mobile Number: "+rs.getInt(3));
while(rs.next())
{
details.add(rs.getInt(1));
details.add(rs.getString(2));
details.add(rs.getString(3));
details.add(rs.getString(4));
details.add(rs.getString(5));
details.add(rs.getString(6));
details.add(rs.getString(7));
details.add(rs.getString(8));
details.add(rs.getString(9));
details.add(rs.getString(10));
details.add(rs.getString(11));
details.add(rs.getString(12));
details.add(rs.getString(13));
details.add(rs.getString(14));
}
for(int i=0;i<details.size();i++)
{
System.out.println(details.get(i));
}
System.out.println("------------Database handler Done------------");
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
closeConnection();
}
return details;
}
以上代码通过接口
调用上面的代码UpdateDeleteForm.java
private class DetailsLoader implements ItemListener
{
public void itemStateChanged(ItemEvent ie)
{
if(ie.getStateChange()==ItemEvent.SELECTED)
{
List details = new ArrayList();
if(nameTxtCombo.getSelectedItem().toString() != "Select a Name")
{
details = dateBaseConnector.getDetails(nameTxtCombo.getSelectedItem().toString());
idTxt.setText("");
firstNameTxt.setText("");
lastNameTxt.setText("");
mobileNumber1Txt.setText("");
mobileNumber2Txt.setText("");
landNumber1Txt.setText("");
landNumber2Txt.setText("");
streetAddressTxt.setText("");
cityTxt.setText("");
countryTxt.setText("");
middleNameTxt.setText("");
emailTxt.setText("");
nickNameTxt.setText("");
String mobileNumber1 = (String)details.get(2)+" ";
String mobileNumber2 = (String)details.get(3)+" ";
String landNumber1 = (String)details.get(4)+" ";
String landNumber2 = (String)details.get(5)+" ";
String address = (String)details.get(6)+" ";
idTxt.setText(String.valueOf(details.get(0)));
firstNameTxt.setText((String)details.get(1));
mobileNumber1Txt.setText(mobileNumber1.trim());
mobileNumber2Txt.setText(mobileNumber2.trim());
landNumber1Txt.setText(landNumber1.trim());
landNumber2Txt.setText(landNumber2.trim());
streetAddressTxt.setText(address.trim());
//categoryCombo.setSelectedItem((String)details.get(7));
nickNameTxt.setText((String)details.get(8));
emailTxt.setText((String)details.get(9));
middleNameTxt.setText((String)details.get(10));
lastNameTxt.setText((String)details.get(11));
cityTxt.setText((String)details.get(12));
countryTxt.setText((String)details.get(13));
System.out.println((String)details.get(2));
System.out.println((String)details.get(3));
System.out.println((String)details.get(4));
System.out.println((String)details.get(5));
System.out.println(address.trim());
System.out.println((String)details.get(7));
System.out.println((String)details.get(8));
System.out.println((String)details.get(9));
System.out.println();
System.out.println();
System.out.println("---------------New Line---------------------");
}
}
}
}
当我使用MS SQLServer时，此代码可以正常工作。但是，现在我将它转移到Apache Derby - Embedded版本。
如果getDetails（）方法返回的任何项为null，则会出现以下错误
Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 2, Size: 0
at java.util.ArrayList.rangeCheck(ArrayList.java:604)
at java.util.ArrayList.get(ArrayList.java:382)
at normal.UpdateDeleteForm$DetailsLoader.itemStateChanged(UpdateDeleteForm.java:438)
at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1225)
at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1282)
at javax.swing.JComboBox.contentsChanged(JComboBox.java:1329)
at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:118)
at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:94)
at javax.swing.JComboBox.setSelectedItem(JComboBox.java:578)
at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:624)
at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(BasicComboPopup.java:835)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:290)
at java.awt.Component.processMouseEvent(Component.java:6504)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at javax.swing.plaf.basic.BasicComboPopup$1.processMouseEvent(BasicComboPopup.java:499)
at java.awt.Component.processEvent(Component.java:6269)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4860)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2713)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
at java.awt.EventQueue.access$000(EventQueue.java:101)
at java.awt.EventQueue$3.run(EventQueue.java:666)
at java.awt.EventQueue$3.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:680)
at java.awt.EventQueue$4.run(EventQueue.java:678)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
如果non为null，则根本没有问题。我记得我在MS SQL Server中遇到了同样的问题，我设法用'isnull'来克服它。我在这里也做了同样的事情，但似乎apn版本的isnull（nullif）无效，因为如果它至少返回一个空格，我没有这个问题!!请帮忙!!
答案 0 :(得分：2)
COALESCE 可以在PreparedStatement中使用
PreparedStatement ps = con.prepareStatement("
select *
from PhoneData
where upper(rtrim(COALESCE(names,''))) ||
upper(rtrim(COALESCE(middleName,''))) ||
upper(rtrim(COALESCE(lastName,''))) = ?");