【JAVA】基于MVC架构Java技术荟萃案例演练

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>

  <named-config name="mvcapp"> 
    <property name="user">root</property>
    <property name="password">root</property>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql:///test</property>
    
    
    <property name="acquireIncrement">5</property>
    <property name="initialPoolSize">10</property>
    <property name="minPoolSize">10</property>
    <property name="maxPoolSize">50</property>

    <!-- intergalactoApp adopts a different approach to configuring statement caching -->
    <property name="maxStatements">20</property> 
    <property name="maxStatementsPerConnection">5</property>

    
  </named-config>
</c3p0-config>

package com.cuit.mvc.db;

import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

/**
 * JDBC操作工具
 * @author 白宁超 http://www.cnblogs.com/baiboy/
 */
public class JdbcUtils {
    /**
     * 释放Connection链接
     * @param connection
     */
    public static void releaseConnection(Connection connection){
        try{
            if(connection!=null) connection.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    private static DataSource dataSource = null;
    
    static{
        dataSource=new ComboPooledDataSource("mvcapp");
    }
    /**
     * 返回数据源的一个Connection对象
     * @return
     * @throws SQLException 
     */
    public static Connection getConnection() throws SQLException{
        return dataSource.getConnection();
    }

}

package com.cuit.mvc.model;

public class Customer {
    
    private int  id;
    private String name;
    private String address;
    private String phone;
    public int getId() {
        return id;
    }
    public Customer() {
        
    }
    public Customer(String name, String address, String phone) {
        this.name = name;
        this.address = address;
        this.phone = phone;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    @Override
    public String toString(){
        return "Customer [id="+id+",name="+name+",address"+address+
                ",phone="+phone+"]";
    }
}

package com.cuit.mvc.dao;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.Connection;
import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import com.cuit.mvc.db.JdbcUtils;

/**
 * 封装了基本的CRUD的方法，以供子类继承使用
 * 当前DAO直接在方法中获取数据库连接
 * @param <T> ：当前DAO处理实体的类型是什么
 * @author 白宁超 http://www.cnblogs.com/baiboy/
 *
 */
public class DAO<T> {
    //此步骤前需要/lib加入commons-dbutils-xx.jar
    private QueryRunner  queryRunner=new QueryRunner();
    private Class<T> clazz;
    public DAO(){
        //Type通过Ctrl+Shift+O进行反射Type选择
        Type superClass=getClass().getGenericSuperclass();
        if(superClass instanceof ParameterizedType){
            ParameterizedType parameterizedType=(ParameterizedType)superClass;
            Type[] typeArgs=parameterizedType.getActualTypeArguments();
            if(typeArgs!=null && typeArgs.length>0){
                if(typeArgs[0] instanceof Class)    clazz=(Class<T>)typeArgs[0];
            }
        }
    }    
    /**
     * 返回某一个字段的值，或者返回数据表中有多少条记录等。
     * @param sql：SQL语句
     * @param args：填充SQL语句的占位符
     * @return
     */
    public <E> E getForValue(String sql,Object ... args) {
        Connection connection=null;
        try{
            connection=JdbcUtils.getConnection();
            return (E) queryRunner.query(connection,sql,new ScalarHandler<T>(),args);
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            JdbcUtils.releaseConnection(connection);
        }
        return null;
    }
    /**
     * 返回T所对应的List
     * @param sql：SQL语句
     * @param args：填充SQL语句的占位符
     * @return
     */
    public List<T> getForList(String sql,Object ... args){
        Connection connection=null;
        try{
            connection=JdbcUtils.getConnection();
            
            return queryRunner.query(connection,sql,new BeanListHandler<>(clazz),args);
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            JdbcUtils.releaseConnection(connection);
        }
        return null;
    }
    /**
     * 返回对应T的一个实体类对象
     * @param sql：SQL语句
     * @param args：填充SQL语句的占位符
     * @return
     */
    public T get(String sql,Object ... args){
        Connection connection=null;
        try{
            connection=JdbcUtils.getConnection();
            return queryRunner.query(connection,sql,new BeanHandler<>(clazz),args);
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            JdbcUtils.releaseConnection(connection);
        }
        return null;
    }
    /**
     * 该方法封装了INSERT、DELETE、UPDATE操作
     * @param sql：SQL语句
     * @param args：填充SQL语句的占位符
     */
    public void update(String sql,Object ... args){
        Connection connection=null;
        try{
            connection=JdbcUtils.getConnection();
            queryRunner.update(connection,sql,args);
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            JdbcUtils.releaseConnection(connection);
        }
    }
}

package com.cuit.mvc.dao;

import java.util.List;

import com.cuit.mvc.model.CriteriaCustomer;
import com.cuit.mvc.model.Customer;

public interface CustomerDAO {
    public List<Customer> getAll();//获取Customer列表信息
    public void save(Customer customer);//对Customer的添加,通过CTRL+T转到定义
    public void update(Customer customer);//对Customer的更新,通过CTRL+T转到定义
    public Customer get(int id);//获取Customer实体
    public void delete(int id);//根据id进行删除
    public long getCountWithName(String name);//返回name相等的记录数
    //cc封装了查询条件，返回查询条件的list
    public List<Customer> getForListWithCriteriaCustomer(CriteriaCustomer cc);
    
}

package com.cuit.mvc.dao.impl;

import java.util.List;

import com.cuit.mvc.dao.CustomerDAO;
import com.cuit.mvc.dao.DAO;
import com.cuit.mvc.model.CriteriaCustomer;
import com.cuit.mvc.model.Customer;

public class CustomerDAOJdbcImpl extends DAO<Customer> implements CustomerDAO{

    public List<Customer> getForListWithCriteriaCustomer(CriteriaCustomer cc) {
        String sql="select * from customers where name like ? and address like ? "
                + "and phone like ?";
        //修改了CriteriaCustomer的getter方法:使其返回字符串中有%%
        //若返回值为null返回%%，若不返回null则返回："%"+字段本身的值+"%"
        //如上效果如：cc.getName()==null？%%:%+name+%
        System.out.println(sql);
        return getForList(sql,cc.getName(),cc.getAddress(),cc.getPhone());
        
    }
    @Override
    public List<Customer> getAll() {
        String sql="select * from customers";
        return getForList(sql);
    }

    @Override
    public void save(Customer customer) {
        String sql="insert customers(name,address,phone) values(?,?,?)";
        update(sql, customer.getName(),customer.getAddress(),customer.getPhone());
    }

    @Override
    public Customer get(int id) {
        String sql="select * from customers where id=?";
        return get(sql,id);
    }

    @Override
    public void delete(int id) {
        String sql="delete  from customers where id=?";
        update(sql, id);
    }

    @Override
    public long getCountWithName(String name) {
        String sql="select count(id) from customers where name=?";
        return getForValue(sql, name);
    }
    
    @Override
    public void update(Customer customer) {
        String sql="update customers set name=?,address=?,phone=? where id=?";
        update(sql,customer.getName(),customer.getAddress(),customer.getPhone(),customer.getId());
    }

}

package com.cuit.mvc.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.lang.reflect.Method;
import java.util.List;

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

import com.cuit.mvc.dao.CustomerDAO;
import com.cuit.mvc.dao.factory.CustomerDAOFactory;
import com.cuit.mvc.dao.impl.CustomerDAOJdbcImpl;
import com.cuit.mvc.dao.impl.CustomerDAOXMLImpl;
import com.cuit.mvc.model.CriteriaCustomer;
import com.cuit.mvc.model.Customer;

public class CustomerServlet extends HttpServlet {

    //private CustomerDAO customerDAO=new CustomerDAOJdbcImpl();
    //private CustomerDAO customerDAO=new CustomerDAOXMLImpl();
    private CustomerDAO customerDAO=CustomerDAOFactory.getInstance().getCustomerDAO();
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

    /*public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String method=request.getParameter("method");
        switch (method) {
        case "add":  add(request,response); break;
        case "query": query(request,response); break;
        case "delete": delete(request,response);break;
        default: break;
        }

    }*/
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        //1 获取servlet路径 诸如：/add.do
        String servletPath=req.getServletPath().substring(1);
        //去除/和.do得到类似于add这样字符串
        String methodName=servletPath.substring(0,servletPath.length()-3);
        //System.out.println(methodName);
        try {
            //利用反射获取获取methodName对应的方法
            Method method = getClass().getDeclaredMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
            //利用反射获取方法
            method.invoke(this, req,resp);
        } catch (Exception e) {
            //出错时候响应出来
            resp.sendRedirect("error.jsp");
        }
    }
    private void edit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
        String forwordPath="/error.jsp";
        //1 获取请求参数id
        String idstr=request.getParameter("id");
        //2 调用CustomeDAO的customerDAO.get(id)获取和id对应的Customer对象customer
        try{
            Customer customer=customerDAO.get(Integer.parseInt(idstr));
            if(customer!=null){
                forwordPath="/updatecustomer.jsp";
                //3 将customer放在request中
                request.setAttribute("customer", customer);
            }
        }catch(Exception e){}
        //4 响应updatecustomer.jsp页面：转发
        request.getRequestDispatcher(forwordPath).forward(request, response);
    }
    private void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
        //1 获取请求参数:id,name,address,phone,oldname
        String id=request.getParameter("id");
        String name=request.getParameter("name");
        String oldname=request.getParameter("oldname");
        String address=request.getParameter("address");
        String phone=request.getParameter("phone");
        //2  检验name是否被占用
        //2.1  比较name和oldname是否相同，若相同name可用，oldname.equals(name)不如equalsIgnoreCase，数据库默认大小写一致的，而equals忽略大小写
        if(!oldname.equalsIgnoreCase(name)){
            //不相同，调用CustomerDAO的getCountWithName(String name)获取name在数据库中是否存在
            long count=customerDAO.getCountWithName(name);
            //大于0， 响应updatecustomer.jsp页面：通过转发响应newcustomer.jsp
            if(count>0){
                // 通过request.getAttribute("message")显示信息，在页面上request.getAttribute("message")的方式显示
                // 表单据回显。address,phone显示提交的新值， name显示oldname，而不是新值
                request.setAttribute("message", "用户名["+name+"]已经被占用，请重新填写！");
                // 方法结束
                request.getRequestDispatcher("/updatecustomer.jsp").forward(request, response);
                return;
            }
        }
        //3 若验证通过，把表单参数封装为一个Customer对象customer
        Customer customer=new Customer(name,address,phone);
        customer.setId(Integer.parseInt(id));
        //4 调用CustomerDAO的update(Customer customer)执行更新操作
        customerDAO.update(customer);
        //5 重定向到query.do
        response.sendRedirect("query.do");
        
    }
    //模糊查询
    private void query(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
        String name=request.getParameter("name");
        String address=request.getParameter("address");
        String phone=request.getParameter("phone");
        CriteriaCustomer cc=new CriteriaCustomer(name,address,phone);
        //1 调用CustomerDAO的getALl方法得到Customer集合
        //List<Customer> sustomers=customerDAO.getAll();获取所有信息列表
        List<Customer> customers=customerDAO.getForListWithCriteriaCustomer(cc);
        //2 把customer的集合放入request
        request.setAttribute("customers", customers);
        //3 转发页面index.jsp（不能使用重定向）
        request.getRequestDispatcher("/index.jsp").forward(request,response);
    }

    private void delete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
        String idstr=request.getParameter("id").trim();
        int id=0;
        try{
            id=Integer.parseInt(idstr);
            customerDAO.delete(id);
        }catch(Exception e){}
        response.sendRedirect("query.do");
    }

    //此方法名称跟页面add添加的action中add.do匹配
    private void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
        //1 获取表单参数：name，address，phone
        String name=request.getParameter("name");
        String address=request.getParameter("address");
        String phone=request.getParameter("phone");
        //2  检验name是否被占用
        //2.1  调用CustomerDAO的getCountWithName(String name)获取name在数据库中是否存在
        long count=customerDAO.getCountWithName(name);
        if(count>0){
        //2.2 若返回值大于0，则相应newcustomer.jsp页面：①在此页面显示一个错误信息②此表单值可以回显
        //     通过request.getAttribute("message")显示信息
        //     通过value="<%=request.getParameter("name")==null?"":request.getParameter("name")%>"回显
            request.setAttribute("message", "用户名["+name+"]已经被占用，请重新填写！");
            request.getRequestDispatcher("/newcustomer.jsp").forward(request, response);
            return;
        }
        //3 若验证通过，把表单参数封装为一个Customer对象customer
        Customer customer=new Customer(name,address,phone);
        //4 调用CustomerDAO的save(Customer customer)执行保存操作
        customerDAO.save(customer);
        //5 重定向到success.jsp页面
        response.sendRedirect("success.jsp");
    }

}

package com.cuit.mvc.test;

import static org.junit.Assert.*;

import java.util.List;

import org.junit.Test;

import com.cuit.mvc.dao.CustomerDAO;
import com.cuit.mvc.dao.impl.CustomerDAOJdbcImpl;
import com.cuit.mvc.model.CriteriaCustomer;
import com.cuit.mvc.model.Customer;

public class CustomerDAOJdbcImplTest {

    private  CustomerDAO customerDAO=new CustomerDAOJdbcImpl();
    @Test
    public void getForListWithCriteriaCustomer(){
        CriteriaCustomer cc=new CriteriaCustomer("Tom", null, null);
        List<Customer> customers=customerDAO.getForListWithCriteriaCustomer(cc);
        System.out.println(customers);
    }
    @Test
    public void testGetAll() {
        List<Customer> customers=customerDAO.getAll();
        System.out.println(customers);
    }

    @Test
    public void testSaveCustomer() {
        Customer customer=new Customer("Baijing","Shanghai","134-2345-9086");
        customerDAO.save(customer);
    }

    @Test
    public void testGetInt() {
        Customer cust=customerDAO.get(0);
        System.out.println(cust);
    }

    @Test
    public void testDelete() {
        customerDAO.delete(2);
    }

    @Test
    public void testGetCountWithName() {
        long count=customerDAO.getCountWithName("Tom");
        System.out.println(count);
    }

}

<%@page import="com.cuit.mvc.model.Customer"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
    
  <script type="text/javascript" src="scripts/jquery.min.js"></script>
  <script type="text/javascript">
     $(function(){
         $('.delete').click(function(){
            var content=$(this).parent().parent().find("td:eq(1)").text();
            var flag=confirm("确定要删除此"+content+"信息？"); 
            return flag; 
         });
     });
  </script>
  </head>
  
  <body>
      <form action="query.do">
         <table>
             <tr>
               <td>CustomerName:</td>
               <td><input type="text" name="name"/></td>
             </tr>
             
              <tr>
               <td>CustomerAddress:</td>
               <td><input type="text" name="address"/></td>
             </tr>
             
              <tr>
               <td>CustomerPhone:</td>
               <td><input type="text" name="phone"/></td>
             </tr>
             
              <tr>
               <td><input type="submit" value="Query"/></td>
               <td><a href="newcustomer.jsp">Create New Customer</a></td>
             </tr>
         </table>
      </form>
      <br/><br/>
      <%
          List<Customer> customers=(List<Customer>)request.getAttribute("customers");
          if(customers!=null && customers.size()>0){
       %>
       <hr>
       <br/><br/>
       <table border="1" cellpadding="10" cellspacing="0">
            <tr>
               <th>ID</th>
               <th>CustomerName</th>
               <th>CustomerAddress</th>
               <th>CustomerPhone</th>
               <th>Update/Delete</th>
            </tr> 
            <% 
              for(Customer customer:customers){
            %>
            <tr>
               <td class="id"><%=customer.getId() %></td>
               <td><%=customer.getName() %></td>
               <td><%=customer.getAddress() %></td>
               <td><%=customer.getPhone() %></td>
               <td>
                   <a  href="edit.do?id=<%=customer.getId() %>">Update</a>
                   <a href="delete.do?id=<%=customer.getId() %>" class="delete">Delete</a>
               </td> 
               </tr>
               <%
                }
                %>
       </table>
       <%
          }
        %>

  </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'error.jsp' starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
    <h4>对不起没有您请求的页面</h4>
    <img style=" height:200px; width: 200; margin: 0 auto;" src="imgs/error.jpg"></img><br/><br>
    <p style="font-size: 25px; color: red;">对不起访问失败！</p>
    
  </body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <%
        Object mes=request.getAttribute("message");
        if(mes!=null){
           out.print("<br>");
           out.print(mes);
           out.print("<br>");
           out.print("<br>");
        }
     %>
    <h1>添加一条新的customer信息</h1>
     <!--此处add.do依赖于CustomerServlet中的add方法名  -->
     <form action="add.do">
         <table>
             <tr>
               <td>CustomerName:</td>
               <td><input type="text" name="name"
                    value="<%=request.getParameter("name")==null?"":request.getParameter("name")%>"/></td>
             </tr>
             
              <tr>
               <td>CustomerAddress:</td>
               <td><input type="text" name="address"
                   value="<%=request.getParameter("address")==null?"":request.getParameter("address")%>"/></td>
             </tr>
             
              <tr>
               <td>CustomerPhone:</td>
               <td><input type="text" name="phone"
                    value="<%=request.getParameter("phone")==null?"":request.getParameter("phone")%>"/></td>
             </tr>
             
              <tr>
               <td colspan="2"><input type="submit" value="Submit"/></td>
             </tr>
         </table>
      </form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <h2>成功添加，保存成功！</h2><br/><br/>
    <h2><a href="index.jsp">Back Index</a></h2>
</body>
</html>

<%@page import="com.cuit.mvc.model.Customer"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
   <%
        Object mes=request.getAttribute("message");
        if(mes!=null){
           out.print("<br>");
           out.print(mes);
           out.print("<br>");
           out.print("<br>");
        }
        String id=null;
        String name=null;
        String oldname=null;
        String address=null;
        String phone=null;
        Customer customer=(Customer)request.getAttribute("customer");
        if(customer!=null){
           id=customer.getId()+"";
           address=customer.getAddress();
           name=customer.getName();
           oldname=customer.getName();
           phone=customer.getPhone();
        }else{
           id=request.getParameter("id");
           name=request.getParameter("oldname");
           oldname=request.getParameter("oldname");
           address=request.getParameter("address");
           phone=request.getParameter("phone");
        }
     %>
    <h1>更新一条新的customer信息</h1>
     <!--此处add.do依赖于CustomerServlet中的add方法名  -->
     <form action="update.do">
         <input type="hidden" name="id" value="<%=customer.getId()%>"/>
         <input type="hidden" name="oldname" value="<%=oldname%>"/>
         <table>
             <tr>
               <td>CustomerName:</td>
               <td><input type="text" name="name" value="<%=name%>"/></td>
             </tr>
             
              <tr>
               <td>CustomerAddress:</td>
               <td><input type="text" name="address"  value="<%=address %>"/></td>
             </tr>
             
              <tr>
               <td>CustomerPhone:</td>
               <td><input type="text" name="phone" value="<%=phone%>"/></td>
             </tr>
             
              <tr>
               <td colspan="2"><input type="submit" value="Submit"/></td>
             </tr>
         </table>
      </form>
</body>
</html>