Java introspection: object to map

Question

I have a Java object obj that has attributes obj.attr1, obj.attr2 etc. The attributes are possibly accessed through an extra level of

Answer 1

You can use JavaBeans introspection for this. Read up on the java.beans.Introspector class:

public static Map introspect(Object obj) throws Exception {
    Map result = new HashMap();
    BeanInfo info = Introspector.getBeanInfo(obj.getClass());
    for (PropertyDescriptor pd : info.getPropertyDescriptors()) {
        Method reader = pd.getReadMethod();
        if (reader != null)
            result.put(pd.getName(), reader.invoke(obj));
    }
    return result;
}

Big caveat: My code deals with getter methods only; it will not find naked fields. For fields, see highlycaffeinated's answer. :-) (You will probably want to combine the two approaches.)