走進spring之springmvc實戰篇（一）

本篇運用springmvc來試着寫一個登錄注冊頁面

在動手之前，我們需要了解下springnvc.這里先獻上一張springmvc的流程圖及講解。

　　Spring的MVC框架是一個基於DispatcherServlet的MVC框架，主要由DispatcherServlet、處理器映射、處理器、視圖解析器、視圖組成。每一個請求最先訪問的都是DispatcherServlet，DispatcherServlet負責轉發每一個Request請求給相應的Handler，Handler處理以后再返回相應的視圖(View)和模型(Model)，返回的視圖和模型都可以不指定，即可以只返回Model或只返回View或都不返回。

Spring MVC的原理框圖:

整個處理過程從一個HTTP請求開始：
1）DispatcherServlet接收到請求后，根據對應配置文件中配置的處理器映射，找到對應的處理器映射項（HandlerMapping），根據配置的映射規則，找到對應的處理器（Handler）。
2）調用相應處理器中的處理方法，處理該請求，處理器處理結束后會將一個ModelAndView類型的數據傳給DispatcherServlet，這其中包含了處理結果的視圖和視圖中要使用的數據。
3）DispatcherServlet根據得到的ModelAndView中的視圖對象，找到一個合適的ViewResolver（視圖解析器），根據視圖解析器的配置，DispatcherServlet將視圖要顯示的數據傳給對應的視圖，最后給瀏覽器構造一個HTTP響應。
DispatcherServlet是整個Spring MVC的核心。它負責接收HTTP請求組織協調Spring MVC的各個組成部分。其主要工作有以下三項：
1）截獲符合特定格式的URL請求。
2）初始化DispatcherServlet上下文對應的WebApplicationContext，並將其與業務層、持久化層的WebApplicationContext建立關聯。
3）初始化Spring MVC的各個組成組件，並裝配到DispatcherServlet中

 

此時，我們已經對springmvc有了一定的了解，如果您對還理不清思路，沒關系，下面讓我們來進行實戰演練，邊練邊學。

首先，讓我們梳理下整體步驟：

1）導入包：springframework-3.0.RELEASE全部的包，servlet-api.jar,spring-webmvc.jar,spring.jar,comoms-logging.jar，jstl.jar

2）配置/WEB-INF下的web.xml,spring配置文件spring-servlet.xml,上下文applicationContext.xml

3）創建相關類：

4）創建/WEB-INF/jsp下的jsp頁面

開始配置XML文件！

web.xml

這里我們定義了請求分發Servlet，即：org.springframework.web.servlet.DispatcherServlet
DispatcherServlet 是Spring MVC 中負責請求調度的核心引擎，所有的請求將由此Servlet 根據配置分發至各個邏輯處理單元。其內部同時也維護了一個ApplicationContext實例。

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <display-name>mvc_loginregist</display-name>

  <!-- servlet定義 -->
  <servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

    <!-- 可以自定義servlet.xml配置文件的位置和名稱，默認為WEB-INF目錄下，名稱為[<servlet-name>]-servlet.xml，如spring-servlet.xml
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring-servlet.xml</param-value>
    </init-param>
    -->
    
    <!-- 設置啟動的優先級，這里表示表示啟動容器時初始化該Servlet -->
    <load-on-startup>1</load-on-startup>
  </servlet>
  
  <!--通過將DispatcherServlet映射到/，聲明了它會作為默認的servlet並且會處理所有請求，包括對靜態資源的請求-->
  <servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
  
  <!-- 配置ContextLoaderListerner -->
  <listener>
    <listener-class>
     org.springframework.web.context.ContextLoaderListener
   </listener-class>
  </listener>
  
  <!-- 可以配置contextConfigLocation初始化參數 
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/court-servlet.xml</param-value>
</context-param>

默認初始化參數為
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/applicationContext.xml</param-value>
</context-param>
這里使用默認參數
-->

  <!-- 跳轉至首頁,首頁訪問地址為http://localhost:8080/項目名-->
  <welcome-file-list>
    <welcome-file>/WEB-INF/jsp/login.jsp</welcome-file>
</welcome-file-list>
</web-app>

sping-servlet.xml

InternalResourceViewResolver在web應用程序的war文件中查找視圖模板。視圖模塊的路徑根據加完前綴和后綴的邏輯視圖名稱來確定，若返回“login”作為邏輯試圖名稱時，它最終會被解析成"/WEB-INF/jsp/login.jsp"路徑

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="
http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">


<!-- ViewResolver  指定了表現層資源的前綴和后綴   -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>  
    <property name="prefix" value="/WEB-INF/jsp/"/>  
    <property name="suffix" value=".jsp"/>  
</bean>

<!--配置處理器映射-->
<bean id="loginMapping"
        class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="doLogin">loginAction</prop><!-- 首字母必須小寫,請求"doLogin"對應loginAction處理 -->
                <prop key="doRegist">registAction</prop>
                <prop key="toRegist">toRegistAction</prop>
                <prop key="toLogin">toLoginAction</prop>
            </props>
        </property>
    </bean>
</beans>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="
http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">


    <!-- 定義ToRegistAction -->
    <bean id="toRegistAction"
    class="com.htgy.actions.ToRegistAction">
    </bean>
    <!-- 定義ToLoginAction -->
    <bean id="toLoginAction"
    class="com.htgy.actions.ToLoginAction">
    </bean>
    
    <!-- 添加處理器配置 -->
    <!---定義LoginAction類-->
    <bean id="loginAction"
        class="com.htgy.actions.LoginAction">
        <property name="commandClass">
            <value>com.htgy.loginform.LoginForm</value>
        </property>
        <!-- 指定失敗要返回的頁面 --> <!-- 需修改 -->
        <property name="lFailView">
            <value>loginFail</value>
        </property>
        <!-- 指定成功要返回的頁面 -->
        <property name="lSuccessView">
            <value>loginSuccess</value>
        </property>
    </bean>
    
    <!-- 定義RegistAction -->
    <bean id="registAction" 
    class="com.htgy.actions.RegistAction"> 
    <property name="commandClass">
            <value>com.htgy.registform.RegistForm</value>
    </property>
    <!-- 注冊成功返回的頁面 -->
    <property name="rSuccessView">
    <value>registSuccess</value>
    </property>
    <!-- 取消注冊返回的頁面 -->
    <property name="rFailView">
     <value>registFail</value>
    </property>
    </bean>
    </beans>

 

下面是java類

LoginAction和RegistAction類繼承了SimpleFormController，它是AbstractFormController的具體實現其功能是從表單中提取參數封裝到command。

LoginAction類

package com.htgy.actions;

/*
 * 登錄Controller層
 */
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.validation.BindException;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleFormController;
import com.htgy.loginform.LoginForm;

public class LoginAction extends SimpleFormController {
    private String lFailView;
    private String lSuccessView;


    public String getLFailView() {
        return lFailView;
    }


    public void setLFailView(String lFailView) {
        this.lFailView = lFailView;
    }


    public String getLSuccessView() {
        return lSuccessView;
    }


    public void setLSuccessView(String lSuccessView) {
        this.lSuccessView = lSuccessView;
    }

    @Override
    protected ModelAndView onSubmit(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
                    throws Exception {
        //講表單的參數封裝到command中
        LoginForm lf = (LoginForm)command;
        if (lf.getAccount().equals("111111") && lf.getPassword().equals("123456")){
            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("LoginForm", lf);
            List<String> msgList = new LinkedList<String>();
            msgList.add("你好，Spring MVC");
            map.put("msg", msgList);
            System.out.println("登錄成功");
            //返回視圖和模型，this.getLSuccessView()為視圖，map為模型
            return new ModelAndView(this.getLSuccessView(),map); 
        }else{
            return new ModelAndView(this.getLFailView());
        }
    }
}

RegsitAction類

package com.htgy.actions;
/*
 * 注冊Controller層
 */
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.validation.BindException;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleFormController;
import com.htgy.registform.RegistForm;

public class RegistAction extends SimpleFormController{
    private String rFailView;
    private String rSuccessView;
    
    
    public String getRFailView() {
        return rFailView;
    }


    public void setRFailView(String rFailView) {
        this.rFailView = rFailView;
    }


    public String getRSuccessView() {
        return rSuccessView;
    }


    public void setRSuccessView(String rSuccessView) {
        this.rSuccessView = rSuccessView;
    }


    @Override
     protected ModelAndView onSubmit(HttpServletRequest request,
                HttpServletResponse response, Object command, BindException errors)
                throws Exception {
        //講表單的參數封裝到command中
        RegistForm rf = (RegistForm)command;
        if (rf.getAccount().equals("111111") && rf.getPassFirst().equals("123456")
                &&rf.getPassSecond().equals("123456")){
            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("LoginForm", rf);
            List<String> msgList = new LinkedList<String>();
            msgList.add("你好，Spring MVC");
            map.put("msg", msgList);
            //返回視圖和模型，this.getRSuccessView()為視圖，map為模型
            return new ModelAndView(this.getRSuccessView(),map);
        }else{
            return new ModelAndView(this.getRFailView());
        }
        }
    
}

SimpleFormController類中的onsubmit方法用於獲取表單傳遞的信息

ToLoginAction類

package com.htgy.actions;

/*
 * 跳轉到login.jsp頁面
 */
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import org.springframework.web.servlet.ModelAndView;  
import org.springframework.web.servlet.mvc.Controller;  
public class ToLoginAction implements Controller {  
    @Override  
    public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {  
         return new ModelAndView("login");
    }  
}  

ToRegistAction類

package com.htgy.actions;

/*
 * 跳轉到regist.jsp頁面
 */
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import org.springframework.web.servlet.ModelAndView;  
import org.springframework.web.servlet.mvc.Controller;  
public class ToRegistAction implements Controller {  
    @Override  
    public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {  
    return new ModelAndView("regist");
    }  
}

 

Controller接口僅僅聲明了一個方法handleRequest，它負責處理請求並返回合適的模型和視圖。

LoginForm類

 

package com.htgy.loginform;

/*
 * 登錄表單類
 */
public class LoginForm {
     private String account;
     private String password;

        public String getPassword() {
            return password;
        }

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

        public String getAccount() {
            return account;
        }

        public void setAccount(String account) {
            this.account = account;
        }
}

 

RegistForm類

package com.htgy.registform;

/*
 * 注冊表單類
 */
public class RegistForm {
    private String account;
    private String passFirst;
    private String passSecond;
    public String getAccount() {
        return account;
    }
    public void setAccount(String account) {
        this.account = account;
    }
    public String getPassFirst() {
        return passFirst;
    }
    public void setPassFirst(String passFirst) {
        this.passFirst = passFirst;
    }
    public String getPassSecond() {
        return passSecond;
    }
    public void setPassSecond(String passSecond) {
        this.passSecond = passSecond;
    }

}

表單類必須具有set和get方法，便於請求的封裝和提取。

jsp頁面

login.jsp

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>登錄</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>
  <center>
    <h1>登陸</h1>
    <hr>
    <%
        request.setCharacterEncoding("utf-8"); //解決中文亂碼問題
    %>
    <form name="regForm" action="doLogin" method="post">
        <table>
            <tr>
                <td>賬號：</td>
                <td><input type="text" name="account" />
                </td>
            </tr>
            <tr>
                <td>密碼：</td>
                <td><input type="password" name="password" />
                </td>
            </tr>
            </table>
            <table>
            <tr>
                <td colspan="1"><input type="submit" value="登錄" /></td>
                <td colspan="1"><input type="reset" value="重置" /></td>
            </tr>
            </table>
    </form>
    <br>還沒有賬號？請注冊<input type="button" value="注冊" onclick="window.location.href='toRegist'"/>
    </center>
  </body>
</html>

loginFail.jsp

 

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>登錄失敗</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>
  <center>
    登錄失敗<a href="toLogin">返回登錄界面</a>
  </center>
  </body>
</html>

 

loginSuccess.jsp

 

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>登錄成功</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>
  <center>
  <h1>登陸成功！！！！！！！！！！</h1>
    <hr>
  </center>
  </body>
</html>

 

 

regist.jsp

 

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>注冊</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>
    <center>
    <%
        request.setCharacterEncoding("utf-8"); //解決中文亂碼問題
    %>
    <h1>注冊</h1><hr>
    <form name="regform" action="doRegist" method="post">
        <table>
            <tr>
                <td>賬號：</td>
                <td><input type="text"  name="account" id="account"  maxLength="10"></td>
            </tr>
            <tr>
                <td>密碼：</td>
                <td><input type="password" name="passFirst" id="passFirst" maxLength="12"  />
                </td>
            </tr>
            <tr>
                <td>確認密碼：</td>
                <td><input type="password" name="passSecond" id="passSecond"  maxLength="12"  />
            </tr>
            <tr>
                <td>用戶名：</td>
                <td><input type="text" name="username"  maxLength="9"/></td>
            </tr>
            </table>
            <table>
            <tr>
                <td colspan="1"><input type="submit" value="注冊" /></td>
                <td colspan="1"><input type="reset" value="重置" /></td>
            </tr>
            </table>
    </form>
    <form name="regForm" action="toLogin">
        <table>
            <tr>
                <td colspan="2"><input type="submit" value="返回登錄界面" />
                </td>
            </tr>
        </table>
    </form>
    </center>
  </body>
</html>

registFail.jsp

 

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>注冊失敗</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>
  <center>
    注冊失敗<br>
    <a href="toRegist">繼續注冊</a>
    <a href="toLogin">返回登錄界面</a>
  </center>
  </body>
</html>

 

registSuccess.jsp

 

<%@ page language="java" import="java.util.*" contentType="text/html; charset=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>注冊成功</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>
     <center>
  <h1>恭喜您！注冊成功</h1><hr>
  返回登陸頁面？<a href="toLogin"/>確定</a>
  </center>
  </body>
</html>

 

大功告成！~

本篇只是讓大家初步了解了springmvc的構建和運行原理，之后我們再通過加入數據庫來進行更深層次的了解。

總結：

1）在最開始接觸springmvc時候，經常會把請求和視圖搞反，正確的理解應該是客戶傳遞請求給dispatcherServlet，dispatcherServlet處理請求后再將相應的視圖傳遞給客戶。