MVC案例，开发用户登录模块（一）

对于MVC相比都不陌生，现在就以MVC设计模式为指导思想写一个真实的案例，先是第一步，规划，和进行必要的开发环境的搭建。

首先是规划

1.搭建开发环境
		1.1导开发包
		dom4j开发包
		jstl开发包
		beanUtils开发包
		log4j开发包
		
		1.2创建组织程序的包
		com.bird.domain
		com.bird.dao
		com.bird.dao.impl
		com.bird.service
		com.bird.service.impl
		com.bird.web.controller
		com.bird.web.ui
		com.bird.utils
		junit.test
		
		WEB-INF/jsp保存所有jsp
		
		
		1.3创建代表数据库的XML文件
		在类目录下创建一个代表数据库的XML文件

然后是充当数据库的user.xml

<?xml version="1.0" encoding="UTF-8"?>
<users>
	<user id="123123124" username="aaa" password="123" email="[e-mail]" birthday = "1992-01-18" nickname="强子"></user>
</users>

然后是作为工具类的Dom4j的工具类的方法

package com.bird.utils;

import java.io.File;
import java.io.FileOutputStream;
import org.dom4j.Document;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XmlUtils {
	private static String filePath;
	
	//静态代码块只获取一次位置
	static{
		//返回绝对地址
		filePath = XmlUtils.class.getClassLoader().getResource("users.xml").getPath();
	}
	
	
	/**
	 * 获得指定文件的Document
	 * @return
	 * @throws Exception
	 */
	public static Document getDocument() throws Exception{
		 SAXReader reader = new SAXReader();
	     Document document = reader.read(new File(filePath));
	     return document;
	}
	
	/**
	 * 将内存中的Document写到磁盘中去
	 * @param document
	 * @throws Exception
	 */
	public static void write2Document(Document document) throws Exception{
		// Pretty print the document to System.out
        OutputFormat format = OutputFormat.createPrettyPrint();
        format.setEncoding("UTF-8");
        XMLWriter writer = new XMLWriter(new FileOutputStream(filePath), format );
        writer.write( document );

        writer.close();
	}
}

然后是封装数据的JavaBean

package com.bird.domain;

import java.util.Date;

public class User {
	private String id;
	private String username;
	private String password;
	private String email;
	private Date birthday;
	private String nickname;
	
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public Date getBirthday() {
		return birthday;
	}
	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}
	public String getNickname() {
		return nickname;
	}
	public void setNickname(String nickname) {
		this.nickname = nickname;
	}
}

然后是Dao层的开发

package com.bird.dao.impl;

import java.text.SimpleDateFormat;

import org.dom4j.Document;
import org.dom4j.Element;

import com.bird.domain.User;
import com.bird.utils.XmlUtils;

public class UserDaoImpl {
	@SuppressWarnings("deprecation")
	public void add(User user){
		try {
			Document document = XmlUtils.getDocument();
			Element root = document.getRootElement();
			
			Element user_tag = root.addElement("user");
			
			user_tag.setAttributeValue("id", user.getId());
			user_tag.setAttributeValue("username", user.getUsername());
			user_tag.setAttributeValue("password", user.getPassword());
			user_tag.setAttributeValue("email", user.getEmail());
			user_tag.setAttributeValue("birthday", user.getBirthday()==null ? "":user.getBirthday().toLocaleString());
			user_tag.setAttributeValue("nickname", user.getNickname());
			
			XmlUtils.write2Document(document);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	
	public User find(String username, String password){
		try {
			Document document = XmlUtils.getDocument();
			Element e = (Element) document.selectSingleNode("//user[@username='"+username+"' and @password='"+password+"']");
			if(e == null){
				return null;
			}
			
			User user = new User();
			String date = e.attributeValue("birthday");
			if(date==null || date.equals("")){
				user.setBirthday(null);
			}else{
				SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
				user.setBirthday(format.parse(date));
			}
			
			user.setEmail(e.attributeValue("email"));
			user.setId(e.attributeValue("id"));
			user.setNickname(e.attributeValue("nickname"));
			user.setPassword(e.attributeValue("password"));
			user.setUsername(e.attributeValue("username"));
			
			return user;
			
		} catch (Exception e) {
			
			throw new RuntimeException(e);
		}
		
	}
	
	/**
	 * 查找在数据库中对应的用户是否存在
	 * @param username
	 * @return
	 */
	public boolean find(String username){
		try {
			Document document = XmlUtils.getDocument();
			Element e = (Element) document.selectSingleNode("//user[@username='"+username+"']");
			if(e == null)
				return false;
			else
				return true;
		} catch (Exception e) {

			throw new RuntimeException(e);
		}
	
	}
}

最后是测试类

package junit.test;

import java.util.Date;

import org.junit.Test;

import com.bird.dao.impl.UserDaoImpl;
import com.bird.domain.User;

public class UserDaoTest {
	
	@Test
	public void testAdd(){
		User use = new User();
		use.setBirthday(new Date());
		use.setEmail("[e-mail]");
		use.setId("123123567");
		use.setNickname("小白");
		use.setPassword("123");
		use.setUsername("abc");
		
		UserDaoImpl dao = new UserDaoImpl();
		dao.add(use);
	}
	
	@Test
	public void testFind(){
		UserDaoImpl dao = new UserDaoImpl();
		dao.find("aaa","123");
	}
	
	@Test
	public void testFindName(){
		UserDaoImpl dao = new UserDaoImpl();
		dao.find("aaa");
	}
}

可以说，还是非常繁琐的