Re: Problem get the value of a field in the Reflection API

From: nos (nos_at_nospam.com)
Date: 01/29/04 

Date: Thu, 29 Jan 2004 22:49:02 GMT

"Richard" <rvlasimsky@voneconsulting.com> wrote in message
news:d72c60b6.0401291431.5bdd89f1@posting.google.com...
> I have written a static method that uses the Reflection API to scrape
> all of the names of the instance variables in a class and their
> corresponding values; and then returns a hashMap containing a
> key/value pair of the name of the variable and its corresponding
> value. My problem is getting the value of the field, and everything I
> have seen on usenet and in the javadoc tells me I am doing the right
> thing. I think I found a bug in the JDK, but thought I'd throw it out
> there to see if I am doing something wrong.
>
> When I use the reflect API, specifically Field.get(Object o), it
> returns the name of the variable, not the value contained in the
> variable.
>
> Note: The object (params) that I am passing in contains only primitive
> types (double, int, etc.). I am using Java(TM) 2 Runtime Environment,
> Standard Edition (build 1.4.2_03-b02).
>
> Here is the code
>
> public static HashMap toHash(Object params)
> {
> try
> {
> HashMap desc = new HashMap();
> Class c = params.getClass();
> Field[] fields = c.getFields();
> for (int i = 0; i < fields.length; i++)
> {
> String key = fields[i].getName(); //PROBLEM #1: field name is in
> ALL CAPS
> Object value = fields[i].get(params); //PROBLEM #2: returns the
> name of the field, not it's value desc.put(key, value);
> }
> return desc;
> }
> catch (SecurityException e)
> {
> MiscUtils.write("Unable to convert parameters to hash. " +
> e.getMessage(), SystemInfo.ERROR_MESSAGE_TYPE);
> e.printStackTrace();
> }
> catch (IllegalArgumentException e)
> {
> MiscUtils.write("Unable to convert parameters to hash. " +
> e.getMessage(), SystemInfo.ERROR_MESSAGE_TYPE);
> e.printStackTrace();
> }
> catch (IllegalAccessException e)
> {
> MiscUtils.write("Unable to convert parameters to hash. " +
> e.getMessage(), SystemInfo.ERROR_MESSAGE_TYPE);
> e.printStackTrace();
> }
> return null;
> }
>
> Any ideas?
I do this (need to instantiate the object first)
then printout of the field name has the correct
upper/lower case. I did not try the value.
-----------------
      CarlPlot cp = new CarlPlot(500, 500);
      className = cp.getClass();

    Field[] fields;
    if (showall)
      fields = cn.getFields();
    else
      fields = cn.getDeclaredFields();

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