java bean 工具类

package org.sharpcode.util;

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.MethodDescriptor;
import java.beans.ParameterDescriptor;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.sharpcode.po.Account;

/**
 * java bean 工具类
 * 
 * @author kingschan
 * 
 */
public class JavaBeanUtil {
	/**
	 * 得到一个bean的方法列表
	 * 
	 * @param clazz
	 * @throws IntrospectionException
	 */
	public static void getBeansMethods(Class<?> clazz)
			throws IntrospectionException {
		// 方法列表
		MethodDescriptor[] methods;
		// 参数列表
		ParameterDescriptor[] parameters;
		methods = Introspector.getBeanInfo(clazz).getMethodDescriptors();
		System.out.println(String.format("%s:共有%s个方法", clazz.getName(),
				methods.length));
		for (MethodDescriptor m : methods) {
			System.out.println(m.getName());
			parameters = m.getParameterDescriptors();
			if (null != parameters) {
				for (ParameterDescriptor p : parameters) {
					System.out.println("parametes:" + p.getName());
				}
			}

		}
	}

	/**
	 * 得到bean的属性名字
	 * 
	 * @param clazz
	 * @throws IntrospectionException
	 * @throws InvocationTargetException
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 */
	public static void getProperty(Object obj) throws IntrospectionException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException {
		// 属性列表
		PropertyDescriptor[] propertys;
		Method method;
		propertys = Introspector.getBeanInfo(obj.getClass())
				.getPropertyDescriptors();
		for (PropertyDescriptor p : propertys) {
			System.out.println(p.getName());
			method = p.getReadMethod();
			// Set<String> set = new HashSet<String>();
			// set.add("accountUsername");
			// getPropertyValue(p,obj,set);
			getPropertyValue(p, obj);

		}
	}

	/**
	 * 得到bean 属性的值
	 * 
	 * @param p
	 * @param obj
	 * @throws InvocationTargetException
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 */
	public static void getPropertyValue(PropertyDescriptor p, Object obj)
			throws IllegalArgumentException, IllegalAccessException,
			InvocationTargetException {
		System.out.println(String.format("key:%s value:%s", p.getName(), p
				.getReadMethod().invoke(obj)));
	}

	/**
	 * 只打出指定属性名
	 * 
	 * @param p
	 * @param obj
	 * @param pname
	 * @throws IllegalArgumentException
	 * @throws IllegalAccessException
	 * @throws InvocationTargetException
	 */
	public static void getPropertyValue(PropertyDescriptor p, Object obj,
			Set<String> pname) throws IllegalArgumentException,
			IllegalAccessException, InvocationTargetException {
		if (pname.contains(p.getName())) {
			System.out.println(String.format("key:%s value:%s", p.getName(), p
					.getReadMethod().invoke(obj)));
		}

	}

	/**
	 * 构建指定的对象 并初始化
	 * 
	 * @param obj
	 *            对象类型
	 * @param map
	 *            key 属性名 value 要初始化的值
	 * @return
	 * @throws IntrospectionException
	 * @throws InvocationTargetException
	 * @throws IllegalAccessException
	 * @throws IllegalArgumentException
	 * @throws ClassNotFoundException
	 * @throws InstantiationException
	 */
	public static Object buildObject(Object obj, Map<String, Object> map)
			throws IntrospectionException, IllegalArgumentException,
			IllegalAccessException, InvocationTargetException,
			ClassNotFoundException, InstantiationException {
		//实例化一个对象
		Object objclass = ((Class<?>) obj).newInstance();
		// 属性列表
		PropertyDescriptor[] propertys;
		Method method;
		Class<?> ptype;// 参数列类
		propertys = Introspector.getBeanInfo(objclass.getClass())
				.getPropertyDescriptors();
		for (PropertyDescriptor p : propertys) {
			//对属性赋值
			if (map.keySet().contains(p.getName())) {
				method = p.getWriteMethod();
				ptype = method.getParameterTypes()[0];
				method.invoke(objclass, map.get(p.getName()));
			}

		}
		return objclass;
	}

	public static void main(String[] args) throws IntrospectionException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException, ClassNotFoundException,
			InstantiationException {		
		HashMap<String, Object> map = new HashMap<String, Object>();
		map.put("accountUsername", "admin");
		map.put("accountId", 100);
		map.put("accountEnable", true);
		Account a = (Account) JavaBeanUtil.buildObject(Account.class, map);
		JavaBeanUtil.getProperty(a);
	}
}