javaee之jsp和Servlet的练习

16-07-25 来源：[db:作者]

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一、现在先使用xml来充当数据库，显示了用户的crud功能：

实体类：

public class User {

	private String id;
	private String name;
	private String password;
	private String gender;
	private String birth;
	private String address;
	private String email;
	
	
	
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	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 getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public String getBirth() {
		return birth;
	}
	public void setBirth(String birth) {
		this.birth = birth;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	public User(String id, String name, String password, String gender,
			String birth, String address,String email) {
		super();
		this.id = id;
		this.name = name;
		this.password = password;
		this.gender = gender;
		this.birth = birth;
		this.address = address;
		this.email = email;
	}
	public User() {
		super();
	}
	
}

逻辑层：

import java.util.List;

import xml_crud.entiry.User;

public interface UserDao {

	/*
	 * 对用户的操作
	 */
	//查找用户
	public List findAll();
	
	public User findById(String id);
	
	public void editUser(User user);
	
	public void delUser(String id);
	
	public void addUser(User user);
}

import java.util.ArrayList;
import java.util.List;

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

import xml_crud.entiry.User;
import xml_crud.util.XMLUtil;

public class UserDaoImpl implements UserDao {

	public List findAll() {
		
		try {
			Document doc = XMLUtil.read();
			Element root = doc.getRootElement();

			//查找到所有的元素进行遍历
			List users = new ArrayList();
			List elements = root.elements();
			for(Element e : elements){
				
				String id = e.attributeValue("id");
				String name = e.elementText("name");
				String password = e.elementText("password");
				String gender = e.elementText("gender");
				String birth = e.elementText("birth");
				String email = e.elementText("email");
				String address = e.elementText("address");
				
				User user = new User(id, name, password, gender, birth, address,email);
				users.add(user);
			
			}
			return users;
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException("，网络异常，请稍后再操作.");
		}
		
		
	}

	public User findById(String id) {
		try{
			Document doc = XMLUtil.read();
			Element element = (Element) doc.getRootElement().selectSingleNode("//user[@id='"+id+"']");
			User user = null;
			
			
			if(element != null){
				user = new User();
				String name = element.elementText("name");
				String password = element.elementText("password");
				String gender = element.elementText("gender");
				String birth = element.elementText("birth");
				String email = element.elementText("email");
				String address = element.elementText("address");
				
				user.setId(id);
				user.setAddress(address);
				user.setBirth(birth);
				user.setEmail(email);
				user.setGender(gender);
				user.setName(name);
				user.setPassword(password);
			}
			
			return user;
		}catch(Exception e){
			e.printStackTrace();
			throw new RuntimeException("，网络异常，请稍后再操作.");
		}
		
		
	}

	public void editUser(User user) {

		try{
			Document doc = XMLUtil.read();
			Element element = (Element) doc.getRootElement().selectSingleNode("//user[@id='"+user.getId()+"']");
			
			
			if(element != null){
				element.element("name").setText(user.getName());
				element.element("password").setText(user.getPassword());
				element.element("gender").setText(user.getGender());
				element.element("address").setText(user.getAddress());
				element.element("email").setText(user.getEmail());
				element.element("birth").setText(user.getBirth());
			}
			
			XMLUtil.writerxml(doc);
		}catch(Exception e){
			e.printStackTrace();
			throw new RuntimeException("，网络异常，请稍后再操作.");
		}
		
	}

	public void delUser(String id) {
		try{
			Document doc = XMLUtil.read();
			Element element = (Element) doc.getRootElement().selectSingleNode("//user[@id='"+id+"']");
			
			if(element != null){
				element.getParent().remove(element);
			}
			
			XMLUtil.writerxml(doc);
			
		}catch(Exception e){
			e.printStackTrace();
			throw new RuntimeException("，网络异常，请稍后再操作.");
		}
	}

	public void addUser(User user) {

		try{
			Document doc = XMLUtil.read();
			Element root = doc.getRootElement();
			
			Element e = root.addElement("user");
			
			e.addAttribute("id", user.getId());
			e.addElement("name").setText(user.getName());
			e.addElement("password").setText(user.getPassword());
			e.addElement("gender").setText(user.getGender());
			e.addElement("email").setText(user.getEmail());
			e.addElement("address").setText(user.getAddress());
			e.addElement("birth").setText(user.getBirth());
			
			XMLUtil.writerxml(doc);
		}catch(Exception e){
			e.printStackTrace();
			throw new RuntimeException("，网络异常，请稍后再操作.");
		}
		
	}

}

视图层：

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import xml_crud.dao.UserDao;
import xml_crud.dao.UserDaoImpl;
import xml_crud.entiry.User;

public class AddUserServlet extends HttpServlet {

	
	private UserDao dao = new UserDaoImpl();
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		request.setCharacterEncoding("utf-8");
		String id = request.getParameter("id");
		String name = request.getParameter("name");
		String password = request.getParameter("password");
		String birth = request.getParameter("birth");
		String address = request.getParameter("address");
		String email = request.getParameter("email");
		String gender = request.getParameter("gender");
		
		User user = new User(id, name, password, gender, birth, address, email);
		
		dao.addUser(user);
		
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().write("添加成功，3秒后跳转");
		response.setHeader("refresh", "3;url="+request.getContextPath()+"/QueryUserServlet");
		
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import xml_crud.dao.UserDao;
import xml_crud.dao.UserDaoImpl;

public class DelUserServlet extends HttpServlet {

	
	private UserDao dao = new UserDaoImpl();
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		String id = request.getParameter("id");
		
		dao.delUser(id);
		
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().write("删除成功，3秒后跳转");
		response.setHeader("refresh", "3;url="+request.getContextPath()+"/QueryUserServlet");
		
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import xml_crud.dao.UserDao;
import xml_crud.dao.UserDaoImpl;
import xml_crud.entiry.User;

public class EditServlet extends HttpServlet {

	
	
	private UserDao dao  = new UserDaoImpl();
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		request.setCharacterEncoding("utf-8");
		String id = request.getParameter("id");
		String name = request.getParameter("name");
		String password = request.getParameter("password");
		String birth = request.getParameter("birth");
		String address = request.getParameter("address");
		String email = request.getParameter("email");
		String gender = request.getParameter("gender");
		
		User us = dao.findById(id);
		us.setAddress(address);
		us.setBirth(birth);
		us.setEmail(email);
		us.setGender(gender);
		us.setName(name);
		us.setPassword(password);
		
		dao.editUser(us);
		
		
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().write("修改成功，3秒后跳转");
		response.setHeader("refresh", "3;url="+request.getContextPath()+"/QueryUserServlet");
		
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import xml_crud.dao.UserDao;
import xml_crud.dao.UserDaoImpl;
import xml_crud.entiry.User;

public class QueryUserServlet extends HttpServlet {

	
	private UserDao dao = new UserDaoImpl();
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		List list = dao.findAll();
		
		request.setAttribute("userlist", list);
		
		request.getRequestDispatcher("/queryUser.jsp").forward(request, response);
		
		
		
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import xml_crud.dao.UserDao;
import xml_crud.dao.UserDaoImpl;
import xml_crud.entiry.User;

public class EditUserServlet extends HttpServlet {

	
	private UserDao dao = new UserDaoImpl();
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		String id = request.getParameter("id");
		User user = dao.findById(id);
		request.setAttribute("user", user);
		
		request.getRequestDispatcher("/editUser.jsp").forward(request, response);
		
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

还有其他的是工具类和xml文件

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XMLUtil {

	/**
	 * 对“数据库”xml的读取操作
	 * @return
	 * @throws Exception
	 */
	public static Document read() throws Exception{
		SAXReader reader = new SAXReader();
		Document doc = reader.read("d:/java/webapps/Myitcast_day09/WEB-INF/classes/user.xml");
		return doc;
	}
	
	
	/**
	 * 对“数据库”xml的写入操作
	 * @param doc
	 * @throws Exception
	 */
	public static void writerxml(Document doc) throws Exception{
		XMLWriter writer = new XMLWriter(
					new FileOutputStream(new File("d:/java/webapps/Myitcast_day09/WEB-INF/classes/user.xml")),
					OutputFormat.createPrettyPrint()
				);
		writer.write(doc);
		writer.close();
	}
}



 
   
    eric  
    1234  
    男  
    1980-09-08  
    eric@qq.com广州天河 
    
   
    eric  
    1234  
    女  
    1987-05-04  
    eric@qq.com广州黄埔 
    
   
    狗娃  
    1234  
    男  
    1987-05-06  
    gouwa@qq.com广州越秀 
    
  
    铁蛋
    1234
    女
    1987-01-01
    tiedan@qq.com广州海珠

通过上面的简单逻辑就能实现用户的crud功能。

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