Problem get the value of a field in the Reflection API

[Richard]

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(Objec t 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 (SecurityExcept ion e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
catch (IllegalArgumen tException e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
catch (IllegalAccessE xception e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
return null;
}

Any ideas?

[nos]

"Richard" <rv********@von econsulting.com > wrote in message
news:d7******** *************** ***@posting.goo gle.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(Objec t 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 (SecurityExcept ion e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
catch (IllegalArgumen tException e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
catch (IllegalAccessE xception e)
{
MiscUtils.write ("Unable to convert parameters to hash. " +
e.getMessage(), SystemInfo.ERRO R_MESSAGE_TYPE) ;
e.printStackTra ce();
}
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.getDeclaredF ields();

[Nic]

If you use javaBeans and javaBeanInfo you can make it.

//Istance of my bean class
Myclass istanceOfMyClas s = new MyClass();
//The Class of my class
Class classOfMyClass= Myclass.class;
//the BeanInfo: contains names and descriptions of the bean (if you
use Forte or NetBeans it's easy to do)
BeanInfo beanInfoOfMyCla ss =
Introspector.ge tBeanInfo(istan ceOfMyClass);
PropertyDescrip tor propertiesOfMyC lass[] =
beanInfoOfMyCla ss.getPropertyD escriptors();

for(int i=0;i<propertie sOfMyClass.leng th;i++){
Method getter = propertiesOfMyC lass[i].getReadMethod( );
Method setter = propertiesOfMyC lass[i].getWriteMethod ();
Object value = getter.invoke(i stanceOfMyClass , new Object[]{});
}

I hope I help you!

By.

Nic

[Richard]

oops. The original code works fine. I was making a stupid mistake.