jfc: adding tab

[Andreas Bauer]

Hi,

I want to load a properties file. I have a class, which returns
a hashtable with all the value. Then in my gui I have
loadActionPerformed-method

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

// TODO add your handling code here:
JFileChooser jfc = new JFileChooser();
jfc.showDialog(workingwindow,"Open");
FileFilters filter = new FileFilters();
File file = jfc.getSelectedFile();
LoadProperties lp = new LoadProperties(file);
JPanel jp = new JPanel();
workingwindow.addTab(jfc.getName(),jp);
Hashtable ht = (Hashtable) lp.loadProperties();
Enumeration props = ht.elements();
while(props.hasMoreElements()){
String key = (String) props.nextElement().toString();
String value = (String) ht.get(key);
jp.add(new JLabel(value));
jp.add(new JTextField(value));
}

But that doesn't work. I get a nullpointerexception.
What have I forgotten?

Thanks in advance for any hint.

Regards,

Andi

 

[Thomas Weidenfeller]

But that doesn't work.

This is the error "description" people hate most here. It is of
absolutely no value, because we don't have magic powers. So please write
some meaningful error description. This should include a complete
example (follow the advice given in
http://www.physci.org/codes/sscce.jsp) and the complete, error message
as given by the compiler (not shortened, not paraphrased).

/Thomas

 

[Andreas Bauer]

private void loadActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JFileChooser jfc = new JFileChooser();
jfc.showDialog(workingwindow,"Open");
FileFilters filter = new FileFilters();
File file = jfc.getSelectedFile();
LoadProperties lp = new LoadProperties(file);
JPanel jp = new JPanel();
workingwindow.addTab(jfc.getName(),jp);
Hashtable ht = (Hashtable) lp.loadProperties();
Enumeration props = ht.elements();
while(props.hasMoreElements()){
String key = (String) props.nextElement().toString();
String value = (String) ht.get(key);
jp.add(new JLabel(value));
jp.add(new JTextField(value));
}

File file = jfc.getSelectedFile();
No file is selected, although getSelectedFile() should return a file.
So I get the following exception:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at
com.brotkasting.prozessgui.LoadProperties.loadProperties(LoadProperties.java:33)
at
com.brotkasting.prozessgui.ProzessGUI.loadActionPerformed(ProzessGUI.java:154)

the loadProperties Method:

try{
FileInputStream fis = new FileInputStream(file);
props.load(fis);
ht = (Hashtable) props.propertyNames();
String test ="EE";
}catch.......