Generate simple class with dexmaker (https://github.com/crittercism/dexmaker)

DexMakerExample.java

/*
    public class Person {
        private String mName;

        public Person() {}

        public String getName() {
            return this.name;
        }

        public void setName(String name) {
            this.name = name;
        }
    }
*/
public class GeneretePerson {
    private static DexMaker dexMaker;
    private File mOutputDir;

    public GeneretePerson(File outputDir) {
        mOutputDir = outputDir;

        dexMaker = new DexMaker();
    }

    public void generate() throws Exception {
        String fileName = "Person.java";

        TypeId<Object> person = TypeId.get("Lcom/example/DexMaker1/Person;");

        dexMaker.declare(person, fileName, Modifier.PUBLIC, TypeId.OBJECT);

        FieldId<Object, String> nameField = person.getField(TypeId.STRING, "mName");

        dexMaker.declare(nameField, PRIVATE, null);

        addDefaultConstructor(person);

        generateGetter("getName", nameField, person);
        generateSetter("setName", nameField, person);

        ClassLoader loader = dexMaker.generateAndLoad(GeneretePerson.class.getClassLoader(), mOutputDir);
        Class<?> personClass = loader.loadClass("com.example.DexMaker1.Person");

        Object o = personClass.newInstance();

        Method[] declaredMethods = personClass.getDeclaredMethods();
        Method getter = null, setter = null;
        if (declaredMethods != null) {
            for (Method method : declaredMethods) {
                if (method.getName().contains("get") || method.getName().contains("is")) {
                    getter = method;
                } else if (method.getName().contains("set")) {
                    setter = method;
                }
            }
        }

        if (getter != null && setter != null) {
            setter.invoke(o, "New Name");

            Object oReturn = getter.invoke(o);
            Log.v("DexMaker", oReturn.toString());
        }
    }


    private <T, V> void generateGetter(String methodName, FieldId<T, V> fieldId, TypeId<T> target) {
        MethodId<?, V> getter = target.getMethod(fieldId.getType(), methodName);
        Code code = dexMaker.declare(getter, PUBLIC);

        Local<V> local = code.newLocal(fieldId.getType());

        Local<T> thiz = code.getThis(target);

        code.iget(fieldId, local, thiz);

        code.returnValue(local);
    }

    private <D, V> void generateSetter(String methodName, FieldId<D, V> fieldId, TypeId<D> target) {
        MethodId<D, Void> setter = target.getMethod(TypeId.VOID, methodName, fieldId.getType());
        Code code = dexMaker.declare(setter, PUBLIC);

        Local<D> thiz = code.getThis(target);

        Local<V> value = code.getParameter(0, fieldId.getType());

        code.iput(fieldId, thiz, value);

        code.returnVoid();
    }

    private void addDefaultConstructor(TypeId<?> typeId) {
        Code code = dexMaker.declare(typeId.getConstructor(), PUBLIC);
        Local<?> thisRef = code.getThis(typeId);
        code.invokeDirect(TypeId.OBJECT.getConstructor(), null, thisRef);
        code.returnVoid();
    }
}