Android and reflection

Question

I get the impression that Android supports reflection. But does it really? How sensible would it be to rely on reflection heavily? What\'s the penalty?

Answer 1

a simple example related to using reflection on android http://aaarkonusurum.blogspot.com/2012/02/android-ile-reflection.html

Class x = Object.class;
Constructor[] constructors = x.getDeclaredConstructors();
Field[] fields = x.getDeclaredFields();
Method[] methods = x.getDeclaredMethods();
for (Constructor constructor : constructors) { 
    //constructors
}
for (Field field : fields) {
    //fields
}
for (Method method : methods) {
    //methods
}    

Creating a TextView from codebehind at runtime with using reflection

String x = TextView.class.toString().replace("class ", "");
Class cls = Class.forName(x);
Class param[] = new Class[1];
param[0] = Context.class; //Context=o an ki context ==> [activity.class]
Constructor ct = cls.getConstructor(param);
Object paramVal[] = new Object[1];
paramVal[0] = context;
Object retobj = ct.newInstance(paramVal); 

Reaching to setText() method at the runtime

Class methodParam[] = new Class[1];
methodParam[0] = java.lang.CharSequence.class;
Method method = cls.getMethod("setText", methodParam);
Object arglist[] = new Object[1];
arglist[0] = new String("THIS TEXTVIEW HAS BEEN CREATED ON RUN TIME");
method.invoke(retobj, arglist);