Request Parameter and Attribute Injection

AbstractEntityBuilder.java

package br.com.wakim.teste_jsf.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public abstract class AbstractEntityBuilder<T, ValueAccessor> {
	
	public T build(Class<T> klass, ValueAccessor v) throws InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException {
		Constructor<T> constructor = klass.getDeclaredConstructor();
		
		if(constructor == null) {
			throw new RuntimeException("No empty Constructor");
		}
		
		T t = constructor.newInstance();
		
		return build(t, v);
	}
	
	public T build(T t, ValueAccessor v) throws IllegalArgumentException, IllegalAccessException, SecurityException, InvocationTargetException {
		iterateOverFields(t, v);
		iterateOverMethods(t, v);
		
		return t;
	}
	
	void iterateOverFields(T t, ValueAccessor v) throws IllegalArgumentException, IllegalAccessException, SecurityException, InvocationTargetException {
		Field[] fields = t.getClass().getDeclaredFields();
		
		for(Field field : fields) {
			RequestInject an = null;
			
			if(field.isAnnotationPresent(RequestInject.class)) {
				an = field.getAnnotation(RequestInject.class);
				
				
				
				if(! isValidAnnotation(an, field, v)) {
					continue;
				}
				
				// Atributo publico
				if(Modifier.isPublic(field.getModifiers())) {
					field.set(t, getValue(field, an, v));
				} else { // Buscamos o setter
					try {
						Method setter = t.getClass().getMethod("set".concat(capitalize(field.getName())), field.getType());
						setter.invoke(t, getValue(setter, an, v));
					} catch(NoSuchMethodException e) {
						e.printStackTrace();
					}
				}
			}
		}
	}
	
	void iterateOverMethods(T t, ValueAccessor v) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		Method[] methods = t.getClass().getDeclaredMethods();
		
		for(Method method : methods) {
			RequestInject an = null;
			
			if(method.isAnnotationPresent(RequestInject.class)) {
				an = method.getAnnotation(RequestInject.class);
				
				if(! isValidAnnotation(an, method, v)) {
					continue;
				}
				
				if(Modifier.isPublic(method.getModifiers())) {
					method.invoke(t, getValue(method, an, v));
				}
			}
		}
	}
	
	String capitalize(String str) {
		StringBuilder sb = new StringBuilder();
		
		sb.append(Character.toUpperCase(str.charAt(0)));
		
		if(str.length() > 1) {
			sb.append(str.substring(1));
		}
		
		return sb.toString();
	}
	
	public abstract boolean isValidAnnotation(RequestInject an, Field field, ValueAccessor v);
	public abstract boolean isValidAnnotation(RequestInject an, Method method, ValueAccessor v);
	
	public abstract Object getValue(Field field, RequestInject an, ValueAccessor v);
	public abstract Object getValue(Method method, RequestInject an, ValueAccessor v);
}

RequestAttributeEntityBuilder.java

package br.com.wakim.teste_jsf.util;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

import javax.faces.context.ExternalContext;

public class RequestAttributeEntityBuilder<T> extends AbstractEntityBuilder<T, ExternalContext> {
	
	<P> P cast(Object obj, Class<P> targetClass) {
		return targetClass.cast(obj);
	}

	@Override
	public boolean isValidAnnotation(RequestInject an, Field field, ExternalContext v) {
		String requestAttributeName = an.name().isEmpty() ? field.getName() : an.name();
		return v.getRequestMap().containsKey(requestAttributeName);
	}
	
	@Override
	public boolean isValidAnnotation(RequestInject an, Method method, ExternalContext v) {
		String requestAttributeName = an.name().isEmpty() ? method.getName() : an.name();
		return v.getRequestMap().containsKey(requestAttributeName);
	}

	@Override
	public Object getValue(Field field, RequestInject an, ExternalContext v) {
		String requestAttributeName = an.name().isEmpty() ? field.getName() : an.name();
		return cast(v.getRequestMap().get(requestAttributeName), field.getType());
	}

	@Override
	public Object getValue(Method method, RequestInject an, ExternalContext v) {
		String requestAttributeName = an.name().isEmpty() ? method.getName() : an.name();
		return cast(v.getRequestMap().get(requestAttributeName), method.getParameterTypes()[0]);
	}
}

RequestParameterEntityBuilder.java

package br.com.wakim.teste_jsf.util;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

import javax.faces.context.ExternalContext;

public class RequestParameterEntityBuilder<T> extends AbstractEntityBuilder<T, ExternalContext> {
	
	<P> P parse(String str, Class<P> targetClass) {
		if(targetClass == String.class) return targetClass.cast(str);
		
		try {
			Method method = targetClass.getMethod("valueOf", String.class);
			return targetClass.cast(method.invoke(null, str));
		} catch (Exception e) {
			throw new RuntimeException("No available Class");
		}
	}

	@Override
	public boolean isValidAnnotation(RequestInject an, Field field, ExternalContext v) {
		String requestParameterName = an.name().isEmpty() ? field.getName() : an.name();
		return v.getRequestParameterMap().containsKey(requestParameterName);
	}
	
	@Override
	public boolean isValidAnnotation(RequestInject an, Method method, ExternalContext v) {
		String requestParameterName = an.name().isEmpty() ? method.getName() : an.name();
		return v.getRequestParameterMap().containsKey(requestParameterName);
	}

	@Override
	public Object getValue(Field field, RequestInject an, ExternalContext v) {
		String requestParameterName = an.name().isEmpty() ? field.getName() : an.name();
		return parse(v.getRequestParameterMap().get(requestParameterName), field.getType());
	}

	@Override
	public Object getValue(Method method, RequestInject an, ExternalContext v) {
		String requestParameterName = an.name().isEmpty() ? method.getName() : an.name();
		return parse(v.getRequestParameterMap().get(requestParameterName), method.getParameterTypes()[0]);
	}
}