使用commons-beanutils封裝請求中的數據與數據類型的轉換，web中使用md5和BASE64Encoder加密

1. 日期類型的使用轉化

package com.heima;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class BeanUtileTest
{
	public static void main(String[] args) throws ParseException
	{
		SimpleDateFormat dateformat1=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss E");
		  String a1=dateformat1.format(new Date());
		  System.out.println("時間2:"+a1);		
		
		  SimpleDateFormat dateformat2=new SimpleDateFormat("yyyy年MM月dd日 HH時mm分ss秒 E ");   
	        String a2=dateformat2.format(new Date());
	        System.out.println("時間2:"+a2); 
	}
}

2. 在Javaweb中數據加密

import java.security.MessageDigest;
import sun.misc.BASE64Encoder;
 class TestMd5AndBase64
{
	public static void main(String[] args)throws Exception
	{
		MessageDigest md = MessageDigest.getInstance("md5");
		String name = "hello";
		byte[] result = md.digest(name.getBytes());
		BASE64Encoder base = new BASE64Encoder();
		String b = new BASE64Encoder().encode(result);
		System.out.println(b);
		
	}
}

3. 將一個所有屬性爲String的bean轉換爲相應的屬性的bean

package com.yueting.bean;
import java.util.Date;
public class UserFormBean
{
	private String name = "zhangsan";
	
	private String password = "helloworld";
	
	private String age = "20";
	
	private String birthday = "2012-12-12";

	public String getName()
	{
		return name;
	}

	public void setName(String name)
	{
		this.name = name;
	}

	public String getPassword()
	{
		return password;
	}

	public void setPassword(String password)
	{
		this.password = password;
	}

	public String getAge()
	{
		return age;
	}

	public void setAge(String age)
	{
		this.age = age;
	}

	public String getBirthday()
	{
		return birthday;
	}

	public void setBirthday(String birthday)
	{
		this.birthday = birthday;
	}
	public static void main(String[] args)
	{
		System.out.println(new Date());
	}
}

2.2 User.java

package com.yueting.bean;
import java.util.Date;
public class User
{
	private String name ;
	
	private String password;
	
	private int age ;

	private Date birthday;
	
	public String getName()
	{
		return name;
	}

	public void setName(String name)
	{
		this.name = name;
	}

	public String getPassword()
	{
		return password;
	}

	public void setPassword(String password)
	{
		this.password = password;
	}
	
	public int getAge()
	{
		return age;
	}

	public void setAge(int age)
	{
		this.age = age;
	}

	public Date getBirthday()
	{
		return birthday;
	}

	public void setBirthday(Date birthday)
	{
		this.birthday = birthday;
	}

	@Override
	public String toString()
	{
		return "User [name=" + name + ", password=" + password + ", age=" + age
				+ ", birthday=" + birthday + "]";
	}
}

3. 將一個請求中的所有數據封裝到一個javabean中

package com.yueying.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import com.yueting.bean.*;
import com.yueting.util.WebUtil;
public class RegisterServlet extends HttpServlet
{
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException
	{
		Person person = null;
		try{
		Person bean = new Person();
		/*第一個種方式直接使用BeanUtile類中的populate方法把請求中的數據直接封裝到一個javabean中*/
//		BeanUtils.populate(bean, req.getParameterMap());
		//第二種方式將BeanUtile類中的populate方法提取出來，作爲一個工具類來使用
		bean = WebUtil.fillBean(req, Person.class);
		
		System.out.println(bean.toString());
		
		}catch (Exception e) {
		e.printStackTrace();
		}
	}
}

2.4 工具類

package com.yueting.util;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.beanutils.BeanUtils;
public class WebUtil
{
	public static <T>T fillBean(HttpServletRequest req, Class<T> clazz)
	{
		T bean ;
		try{
		//獲取clazz的實例
		bean = clazz.newInstance();
		//將req中的數據映射到bean中
		BeanUtils.populate(bean, req.getParameterMap());
		return bean;
		}catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}
}