Field.get(Object obj) now returning null with Generics (Java 5.0) ??

Question

Hello,
I'm currently using Java 5.0 (especially for the Generics part) on a new Java/J2EE project, but having a strange issue with code working previously in a Java 1.4 project.
Below is an overriding of the toString() method provided by the Object class which allow me to view nicely in debug (dev. mode) the contents of my Transfer Objects (all the TO's must extend this ATO abstract class).
Previously this code displayed me something like:
[field1 => value1, field2 => value2] ... for a TO (sort of "Javabean") having e.g. two String fields with values initialized to "value1" (resp. "value2").
But unfortunately, this does (or seems) not to work anymore, having such display :
[field1 => null, field2 => null]I tried to debug, and the problem is that the call fieldValue = field.get(this); returns null while it should returns the actual value of the field.
I thing it it strongly related to Generics, but could not at the moment found how/why it does not work.
May someone help...? Thanks.
public abstract class ATO {
    // Reflection for field value display
    public String toString() {
        StringBuffer sb = new StringBuffer("[");
        MessageFormat mf = new MessageFormat("{0} => {1}, ");
        Field[] fields = this.getClass().getDeclaredFields();
        for (int i = 0; i < fields.length; i++) {
            Field field = (Field) fields;
String fieldName = field.getName();
Object fieldValue = null;
try {
fieldValue = field.get(this);
} catch (IllegalArgumentException e) {
} catch (IllegalAccessException e) {
mf.format(new Object[] { fieldName, fieldValue }, sb, null);
if (sb.length() > 1) {
sb.setLength(sb.length() - 2);
sb.append("]");
return sb.toString();

Answer 1

ejp wrote:
Field field = (Field) fields;
This cast is unnecessary.
Effectively, I haven't noticed it yet. Fixed.
} catch (IllegalArgumentException e) {
} catch (IllegalAccessException e) {
}Either the field value really is null or you are getting one of these exceptions which you are ignoring. Never write empty catch blocks.That's true, I missed something. Fixed with some code to log the eventual exceptions.
Thanks for you answer.