在没有学到java 反射的时候 接触了Beanutils。Beanutils可以将一个表单的request.getParameterMap().直接得到一个JavaBean对象，一直都是一个个request.getParameter("xxx")的获取表单数据，实在不方便，所以接触到Beanutils之后，很好奇是如何实现的，这几天看了一下java反射，写了个简易的Beanutils，只实现了map到JavaBean的转化，开始时没有想好怎么搞，在转换器的扩展性上停了一会儿。

package hcysoul.Bean;import java.util.Date;public class Person {private String name;private int age;private String address;private Date birthday;public Date getBirthday() {	return birthday;}public void setBirthday(Date birthday) {	this.birthday = birthday;}public String getName() {	return name;}public void setName(String name) {	this.name = name;}public int getAge() {	return age;}public void setAge(int age) {	this.age = age;}public String getAddress() {	return address;}public void setAddress(String address) {	this.address = address;}@Overridepublic String toString() {	return "Person [name=" + name + ", age=" + age + ", address=" + address			+ ", birthday=" + birthday + "]";}}

package hcysoul.MyBeanUtils;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.Map;import java.util.Set;	interface Convertor{//先规定一个转换器的接口，转换器必须实现此接口	 Object parse(String className) throws ParseException;	}	class	Intconvertor implements Convertor{//int转换器		@Override		public Object parse(String str) {			// TODO Auto-generated method stub			return Integer.parseInt(str);		}		public String toString(){			return int.class.toString();		}	}	class	Doubleconvertor implements Convertor{		@Override		public Object parse(String str) {			// TODO Auto-generated method stub			return Double.parseDouble(str);					}		public String toString(){			return double.class.toString();		}	}	class	Stringconvertor implements Convertor{		@Override		public Object parse(String str) {			// TODO Auto-generated method stub			return str.toString();					}		public String toString(){			return String.class.toString();		}	}	class	Booleanconvertor implements Convertor{		@Override		public Object parse(String str) {			// TODO Auto-generated method stub			return Boolean.parseBoolean(str);		}		public String toString(){			return Boolean.class.toString();		}	}	class	Longconvertor implements Convertor{		@Override		public Object parse(String str) {			// TODO Auto-generated method stub			return Long.parseLong(str);		}		public String toString(){			return long.class.toString();		}	}	class	Dateconvertor implements Convertor{//Date转换器不是预设转换器。用于后边测试。		@Override		public Object parse(String str) throws ParseException {			// TODO Auto-generated method stub			SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");			return sdf.parseObject(str);		}		public String toString(){			return Date.class.toString();		}	}public class MyBeanUtils {	static ArrayList
    
      convertors=new ArrayList
     
      ();//将所有转换器放入list用于之后的转换器匹配匹配	static {//静态代码块中先将几个预设的转换器放进去		convertors.add(new Intconvertor());		convertors.add(new Doubleconvertor());		convertors.add(new Booleanconvertor());		convertors.add(new Longconvertor());		convertors.add(new Stringconvertor());	}		public static  void register(Convertor convertor){//注册就是将转换器添加到list中，用于之后匹配		convertors.add(convertor);	}	public static Object maptobean(Map
      
        map,String className) throws ClassNotFoundException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, ParseException{//核心		Class clazz=Class.forName(className);		Method[] methods=clazz.getMethods();		Object obj=clazz.newInstance();		Set
       
         set=map.keySet();	for(String var:set){		for(Method method:methods){			if(("set"+Character.toUpperCase(var.charAt(0))+var.substring(1)).equals(method.getName())){//判断方法名是否相同			for(Convertor convertor:convertors){				String typename1=method.getParameterTypes()[0].toString();//因为重写了toString（）方法 所以比较的是xx.class.toString()				String typename2=convertor.toString();					if(typename1.equals(typename2))//匹配转换器，					{						method.invoke(obj, convertor.parse(map.get(var)));						break;					}				}                            }			}		}		return obj;	}     public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, ParseException {	Map
        
          map=new HashMap
         
          (); System.out.println(String.class.toString()); register(new Dateconvertor());//Date转换器不是预设的所以要用到先注册。 map.put("name", "hcysoul"); map.put("age", "20"); map.put("address", "hb"); map.put("birthday", "1993-09-07 17:51:53"); Object obj=maptobean(map,"hcysoul.Bean.Person"); System.out.println(obj); }