反射工具类 java反射

常用的反射工具类ReflectionExtUtil.util

package com.gbcom.system.utils;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.log4j.Logger;

/**
 * 反射工具栏
 * 
 * @author syz
 * @date 2014-5-8
 * @version v1.0.0
 * @see com.gbcom.dp.reflection.ReflectionExtUtil
 */
public class ReflectionExtUtil {

	private static final Logger LOG = Logger.getLogger(ReflectionExtUtil.class);
	
	/**
	 * 新建实例,要么不写构造函数，否则必须有一个默认构造函数
	 * 
	 * @param className
	 *            类名
	 * @param args
	 *            构造函数的参数
	 * @return 新建的实例
	 * @throws Exception
	 *             Exception
	 */
	public static Object newInstance(String className, Object[] args)
			throws Exception {
		Class newoneClass = Class.forName(className);
		if (args == null) {
			return newoneClass.newInstance();
		}
		Class[] argsClass = new Class[args.length];

		for (int i = 0, j = args.length; i < j; i++) {
			argsClass[i] = args[i].getClass();
		}

		Constructor cons = newoneClass.getConstructor(argsClass);

		return cons.newInstance(args);

	}

	/**
	 * 是不是某个类的实例
	 * 
	 * @param obj
	 *            实例
	 * @param cls
	 *            类
	 * @return 如果 obj 是此类的实例，则返回 true
	 */
	public static boolean isInstance(Object obj, Class cls) {
		return cls.isInstance(obj);
	}

	/**
	 * 循环向上转型, 获取对象的 DeclaredMethod
	 * 
	 * @param object
	 *            : 子类对象
	 * @param methodName
	 *            : 父类中的方法名
	 * @param parameterTypes
	 *            : 父类中的方法参数类型
	 * @return 父类中的方法对象
	 */

	public static Method getDeclaredMethod(Object object, String methodName,
			Class<?>... parameterTypes) {
		Method method = null;

		for (Class<?> clazz = object.getClass(); clazz != Object.class; clazz = clazz
				.getSuperclass()) {
			try {
				method = clazz.getDeclaredMethod(methodName, parameterTypes);
				return method;
			} catch (Exception e) {
				// 这里甚么都不要做！并且这里的异常必须这样写，不能抛出去。
				// 如果这里的异常打印或者往外抛，则就不会执行clazz =
				// clazz.getSuperclass(),最后就不会进入到父类中了

			}
		}

		return null;
	}

	/**
	 * 直接调用对象方法, 而忽略修饰符(private, protected, default)
	 * 
	 * @param object
	 *            : 子类对象
	 * @param methodName
	 *            : 父类中的方法名
	 * @param parameterTypes
	 *            : 父类中的方法参数类型
	 * @param parameters
	 *            : 父类中的方法参数
	 * @return 父类中方法的执行结果
	 */

	public static Object invokeMethod(Object object, String methodName,
			Class<?>[] parameterTypes, Object[] parameters) {
		// 根据 对象、方法名和对应的方法参数 通过反射 调用上面的方法获取 Method 对象
		Method method = getDeclaredMethod(object, methodName, parameterTypes);

		// 抑制Java对方法进行检查,主要是针对私有方法而言
		method.setAccessible(true);

		try {
			if (null != method) {

				// 调用object 的 method 所代表的方法，其方法的参数是 parameters
				return method.invoke(object, parameters);
			}
		} catch (IllegalArgumentException e) {
			LOG.error("error",e);
		} catch (IllegalAccessException e) {
			LOG.error("error",e);
		} catch (InvocationTargetException e) {
			LOG.error("error",e);
		}

		return null;
	}

	private static Field[] arryConcat(Field[] a, Field[] b) {
		Field[] c = new Field[a.length + b.length];
		System.arraycopy(a, 0, c, 0, a.length);
		System.arraycopy(b, 0, c, a.length, b.length);
		return c;
	}

	private static Method[] arryConcat(Method[] a, Method[] b) {
		Method[] c = new Method[a.length + b.length];
		System.arraycopy(a, 0, c, 0, a.length);
		System.arraycopy(b, 0, c, a.length, b.length);
		return c;
	}

	/**
	 * 获取对象的所有属性，包括父类
	 * 
	 * @param object
	 *            Object
	 * @return Field []
	 */
	public static Field[] getDeclaredFields(Object object) {
		Class<?> clazz = object.getClass();
		Field[] total = new Field[0];
		for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
			total = (Field[]) arryConcat(total, clazz.getDeclaredFields());
		}
		return total;
	}

	/**
	 * 获取对象的所有属性，包括父类
	 * 
	 * @param clazz
	 *            Class<?>
	 * @return Field []
	 */
	public static Field[] getDeclaredFields(Class<?> clazz) {
		Field[] total = new Field[0];
		for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
			total = (Field[]) arryConcat(total, clazz.getDeclaredFields());
		}
		return total;
	}

	/**
	 * 获取对象的所有方法
	 * 
	 * @param object
	 *            Object
	 * @return Method []
	 */
	public static Method[] getDeclaredMethods(Object object) {
		Class<?> clazz = object.getClass();
		Method[] total = new Method[0];
		for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
			total = (Method[]) arryConcat(total, clazz.getDeclaredMethods());
		}
		return total;
	}

	/**
	 * 循环向上转型, 获取对象的 DeclaredField
	 * 
	 * @param object
	 *            : 子类对象
	 * @param fieldName
	 *            : 父类中的属性名
	 * @return 父类中的属性对象
	 */

	public static Field getDeclaredField(Object object, String fieldName) {
		Field field = null;

		Class<?> clazz = object.getClass();

		for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
			try {
				field = clazz.getDeclaredField(fieldName);
				return field;
			} catch (Exception e) {
			}
		}

		return null;
	}

	/**
	 * 直接设置对象属性值, 忽略 private/protected 修饰符, 也不经过 setter
	 * 
	 * @param object
	 *            : 子类对象
	 * @param fieldName
	 *            : 父类中的属性名
	 * @param value
	 *            : 将要设置的值
	 */

	public static void setFieldValue(Object object, String fieldName,
			Object value) {

		// 根据 对象和属性名通过反射 调用上面的方法获取 Field对象
		Field field = getDeclaredField(object, fieldName);

		// 抑制Java对其的检查
		field.setAccessible(true);

		try {
			// 将 object 中 field 所代表的值 设置为 value
			field.set(object, value);
		} catch (IllegalArgumentException e) {
			LOG.error("error",e);
		} catch (IllegalAccessException e) {
			LOG.error("error",e);
		}

	}

	/**
	 * 直接读取对象的属性值, 忽略 private/protected 修饰符, 也不经过 getter
	 * 
	 * @param object
	 *            : 子类对象
	 * @param fieldName
	 *            : 父类中的属性名
	 * @return : 父类中的属性值
	 */

	public static Object getFieldValue(Object object, String fieldName) {

		// 根据 对象和属性名通过反射 调用上面的方法获取 Field对象
		Field field = getDeclaredField(object, fieldName);

		// 抑制Java对其的检查
		field.setAccessible(true);

		try {
			// 获取 object 中 field 所代表的属性值
			return field.get(object);

		} catch (Exception e) {
			LOG.error("error",e);
		}

		return null;
	}

	/**
	 * 设置属性值
	 * 
	 * @param list
	 *            ArrayList
	 * @param cla
	 *            Class
	 * @return ArrayList
	 */
	@SuppressWarnings("unchecked")
	public static ArrayList array2bean(ArrayList list, Class cla) {
		ArrayList result = new ArrayList();
		int filedLen = cla.getDeclaredFields().length;
		System.out.println(":" + cla.getDeclaredFields().length);
		for (int i = 0; i < list.size(); i++) {
			Object[] o = (Object[]) list.get(i);
			int length = filedLen < o.length ? filedLen : o.length;
			try {
				result.add(cla.newInstance());
				for (int j = 0; j < length; j++) {
					Method m = null;
					String mName = cla.getDeclaredFields()[j].getName();
					mName = mName.substring(0, 1).toUpperCase()
							+ mName.substring(1);
					mName = "set" + mName;
					m = cla.getMethod(mName, new Class[] { String.class });
					// 调用设置的方法，给属性赋值
					m.invoke(result.get(i), new Object[] { o[j] == null ? ""
							: o[j].toString() });
				}
			} catch (Exception e) {
				LOG.error("error",e);
			}
		}
		return result;
	}

	/**
	 * 
	 * @param cla
	 *            String
	 * @param attri
	 *            Class
	 * @return Class
	 */
	public static Class getAttriTypeByName(Class cla, String attri) {
		Field[] fds = getDeclaredFields(cla);
		for (Field field : fds) {
			if (field.getName().equals(attri)) {
				return field.getType();
			}
		}
		return String.class;
	}

	/**
	 * 获取对象的所有属性的 valueMap
	 * 
	 * @param obj
	 *            Object
	 * @return Map<String, Object>
	 * @throws SecurityException
	 *             SecurityException
	 * @throws NoSuchMethodException
	 *             NoSuchMethodException
	 * @throws IllegalArgumentException
	 *             IllegalArgumentException
	 * @throws IllegalAccessException
	 *             IllegalAccessException
	 * @throws InvocationTargetException
	 *             InvocationTargetException
	 */
	public static Map<String, Object> getAttrsValueMap(Object obj)
			throws SecurityException, NoSuchMethodException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException {
		Map<String, Object> valueMap = new HashMap<String, Object>();
		Class cla = obj.getClass();
		Field[] fds = getDeclaredFields(obj);
		Field field = null;
		String fieldName = null;
		String methodName = null;
		Method method = null;
		Object returnValue = null;
		for (int i = 0; i < fds.length; i++) {
			field = fds[i];
			fieldName = field.getName();
			methodName = "get" + fieldName.substring(0, 1).toUpperCase()
					+ fieldName.substring(1);
			method = getDeclaredMethod(obj, methodName, null);
			if (method == null) {
				methodName = "is" + fieldName.substring(0, 1).toUpperCase()
						+ fieldName.substring(1);
				method = getDeclaredMethod(obj, methodName, null);
			}
			if (method == null) {
				System.out
						.println("NullPoint exception , of reflection methodName="
								+ methodName);
				continue;
			}
			returnValue = method.invoke(obj, null);// 调用方法，相当于执行get方法得到的结果，这里返回的是一个对象
			valueMap.put(fieldName, returnValue == null ? "" : returnValue);
		}

		return valueMap;
	}

	/**
	 * 根据MAP 设置对象的所有属性，
	 * 
	 * @param obj
	 *            Object
	 * @param valueMap
	 *            Map<String, Object>
	 * @throws NoSuchMethodException
	 *             NoSuchMethodException
	 * @throws SecurityException
	 *             SecurityException
	 * @throws InvocationTargetException
	 *             InvocationTargetException
	 * @throws IllegalAccessException
	 *             IllegalAccessException
	 * @throws IllegalArgumentException
	 *             IllegalArgumentException
	 */
	public static void setAttrsValueMap(Object obj, Map<String, Object> valueMap)
			throws SecurityException, NoSuchMethodException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException {
		Class cla = obj.getClass();

		String fieldName = null;
		String methodName = null;
		Method method = null;
		for (Entry<String, Object> entry : valueMap.entrySet()) {
			// 预判断
			if (entry.getValue() == null
					|| String.valueOf(entry.getValue()).startsWith("noSuch")) {
				continue;
			}
			fieldName = entry.getKey();
			if (fieldName.equals("staticChannel")) {
				System.out.println("xxx");
			}
			methodName = "set" + fieldName.substring(0, 1).toUpperCase()
					+ fieldName.substring(1);
			Class type = entry.getValue().getClass();
			if (type == Integer.class) {
				type = int.class;
			} else if (type == Boolean.class) {
				type = boolean.class;
			}
			// Object varObj = convertClxValue(type, entry.getValue());
			method = getDeclaredMethod(obj, methodName, type);
			// if(method == null){
			// type = int.class;
			// method = getDeclaredMethod(obj,methodName, type);
			// }
			if (method == null) {
				System.out
						.println("NullPoint exception , of reflection methodName="
								+ methodName);
				continue;
			}
			method.invoke(obj, entry.getValue());// 调用方法，set操作注意
		}
	}

	private static Object convertClxValue(Object value) {
		if (value instanceof String) {
			return String.valueOf(value);
		}
		return null;
	}

}