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package com.firefly.utils;

import com.firefly.utils.classproxy.ArrayProxyFactoryUsingJavassist;
import com.firefly.utils.classproxy.FieldProxyFactoryUsingJavassist;
import com.firefly.utils.classproxy.MethodProxyFactoryUsingJavassist;
import com.firefly.utils.collection.ConcurrentReferenceHashMap;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public abstract class ReflectUtils {

	private static final ConcurrentReferenceHashMap, Map> getterCache = new ConcurrentReferenceHashMap<>(256);
	private static final ConcurrentReferenceHashMap, Map> setterCache = new ConcurrentReferenceHashMap<>(256);
	private static final ConcurrentReferenceHashMap, Map> propertyCache = new ConcurrentReferenceHashMap<>(256);

	public static ProxyFactory defaultArrayProxy = ArrayProxyFactoryUsingJavassist.INSTANCE;
	public static ProxyFactory defaultFieldProxy = FieldProxyFactoryUsingJavassist.INSTANCE;
	public static ProxyFactory defaultMethodProxy = MethodProxyFactoryUsingJavassist.INSTANCE;

	public static interface BeanMethodFilter {
		public boolean accept(String propertyName, Method method);
	}

	public static interface BeanFieldFilter {
		public boolean accept(String propertyName, Field field);
	}

	public static interface MethodProxy {

		Method method();

		/**
		 * Executes this method
		 * 
		 * @param obj
		 *            The instance of object that contains this method
		 * @param args
		 *            The parameters of this method
		 * @return Return value of this method
		 */
		Object invoke(Object obj, Object... args);
	}

	public static interface FieldProxy {

		Field field();

		Object get(Object obj);

		void set(Object obj, Object value);
	}

	public static interface ArrayProxy {
		int size(Object array);

		Object get(Object array, int index);

		void set(Object array, int index, Object value);
	}

	public static interface ProxyFactory {
		ArrayProxy getArrayProxy(Class clazz) throws Throwable;

		FieldProxy getFieldProxy(Field field) throws Throwable;

		MethodProxy getMethodProxy(Method method) throws Throwable;
	}

	public static void setProperty(Object obj, String property, Object value) throws Throwable {
		getFields(obj.getClass()).get(property).set(obj, value);
	}

	public static Object getProperty(Object obj, String property) throws Throwable {
		return getFields(obj.getClass()).get(property).get(obj);
	}

	/**
	 * Invokes a object's "setter" method by property name
	 * 
	 * @param obj
	 *            The instance of a object
	 * @param property
	 *            The property name of this object
	 * @param value
	 *            The parameter of "setter" method that you want to set
	 * @throws Throwable
	 *             A runtime exception
	 * 
	 */
	public static void set(Object obj, String property, Object value) throws Throwable {
		getSetterMethod(obj.getClass(), property).invoke(obj, value);
	}

	/**
	 * Invokes a object's "getter" method by property name
	 * 
	 * @param obj
	 *            The instance of a object
	 * @param property
	 *            The property name of this object
	 * 
	 * @return The value of this property
	 * 
	 * @throws Throwable
	 *             A runtime exception
	 */
	public static Object get(Object obj, String property) throws Throwable {
		return getGetterMethod(obj.getClass(), property).invoke(obj);
	}

	public static Object arrayGet(Object array, int index) throws Throwable {
		return getArrayProxy(array.getClass()).get(array, index);
	}

	public static void arraySet(Object array, int index, Object value) throws Throwable {
		getArrayProxy(array.getClass()).set(array, index, value);
	}

	public static int arraySize(Object array) throws Throwable {
		return getArrayProxy(array.getClass()).size(array);
	}

	public static ArrayProxy getArrayProxy(Class clazz) throws Throwable {
		return defaultArrayProxy.getArrayProxy(clazz);
	}

	public static FieldProxy getFieldProxy(Field field) throws Throwable {
		return defaultFieldProxy.getFieldProxy(field);
	}

	public static MethodProxy getMethodProxy(Method method) throws Throwable {
		return defaultMethodProxy.getMethodProxy(method);
	}

	/**
	 * Gets the all interface names of this class
	 * 
	 * @param c
	 *            The class of one object
	 * @return Returns the all interface names
	 */
	public static String[] getInterfaceNames(Class c) {
		Class[] interfaces = c.getInterfaces();
		List names = new ArrayList();
		for (Class i : interfaces) {
			names.add(i.getName());
		}
		return names.toArray(new String[0]);
	}

	public static String getPropertyName(Method method) {
		String methodName = method.getName();
		int index = (methodName.charAt(0) == 'i' ? 2 : 3);
		char c = methodName.charAt(index);
		if (Character.isLowerCase(c)) {
			return methodName.substring(index);
		} else {
			return Character.toLowerCase(methodName.charAt(index)) + methodName.substring(index + 1);
		}
	}

	public static Method getSetterMethod(Class clazz, String propertyName) {
		return getSetterMethods(clazz).get(propertyName);
	}

	public static Map getSetterMethods(Class clazz) {
		return setterCache.get(clazz, (key) -> { return getSetterMethods(key, null);});
	}

	public static Map getSetterMethods(Class clazz, BeanMethodFilter filter) {
		Map setMethodMap = new HashMap();
		Method[] methods = clazz.getMethods();

		for (Method method : methods) {
			method.setAccessible(true);
			if (method.getName().length() < 4 
					|| !method.getName().startsWith("set") 
					|| Modifier.isStatic(method.getModifiers())
					|| !method.getReturnType().equals(Void.TYPE) 
					|| method.getParameterTypes().length != 1)
				continue;

			String propertyName = getPropertyName(method);
			if (filter == null || filter.accept(propertyName, method))
				setMethodMap.put(propertyName, method);
		}
		return setMethodMap;
	}

	public static Method getGetterMethod(Class clazz, String propertyName) {
		return getGetterMethods(clazz).get(propertyName);
	}

	public static Map getGetterMethods(Class clazz) {
		return getterCache.get(clazz, (key) -> { return getGetterMethods(key, null);});
	}

	public static Map getGetterMethods(Class clazz, BeanMethodFilter filter) {
		Map getMethodMap = new HashMap();
		Method[] methods = clazz.getMethods();
		for (int i = 0; i < methods.length; i++) {
			Method method = methods[i];
			method.setAccessible(true);
			String methodName = method.getName();

			if (Modifier.isStatic(method.getModifiers()))
				continue;
			if (Modifier.isAbstract(method.getModifiers()))
				continue;
			if (method.getName().equals("getClass"))
				continue;
			if (!(method.getName().startsWith("is") || method.getName().startsWith("get")))
				continue;
			if (method.getParameterTypes().length != 0)
				continue;
			if (method.getReturnType() == void.class)
				continue;
			int index = (methodName.charAt(0) == 'i' ? 2 : 3);
			if (methodName.length() < index + 1)
				continue;

			String propertyName = getPropertyName(method);
			if (filter == null || filter.accept(propertyName, method))
				getMethodMap.put(propertyName, method);
		}

		return getMethodMap;
	}

	public static Map getFields(Class clazz) {
		return propertyCache.get(clazz, (key) -> { return getFields(key, null);});
	}

	public static Map getFields(Class clazz, BeanFieldFilter filter) {
		Map fieldMap = new HashMap();
		Field[] fields = clazz.getFields();
		for (Field field : fields) {
			field.setAccessible(true);
			if (Modifier.isStatic(field.getModifiers()))
				continue;

			String propertyName = field.getName();
			if (filter == null || filter.accept(propertyName, field))
				fieldMap.put(propertyName, field);
		}
		return fieldMap;
	}

	public static void copy(Object src, Object dest) {
		Map getterMethodMap = ReflectUtils.getGetterMethods(src.getClass());
		Map setterMethodMap = ReflectUtils.getSetterMethods(dest.getClass());

		for (Map.Entry entry : setterMethodMap.entrySet()) {
			Method getter = getterMethodMap.get(entry.getKey());
			if (getter == null)
				continue;

			try {
				Object obj = getter.invoke(src);
				if (obj != null) {
					entry.getValue().invoke(dest, obj);
				}
			} catch (Throwable t) {
				System.err.println("copy object exception, " + t.getMessage());
			}
		}
	}
}




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