springMVC的视图层解析与服务层调用

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这次项目用的平台是Zookeeper+Dubbo+SpringMVC+Mybatis，再次熟悉一下springMVC的搭建流程。
工程项目目录：
这里写图片描述
创建Web.xml：

<?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">    <!-- 配置spring的servlet -->    <servlet>        <servlet-name>springMVC</servlet-name>        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>        <!-- 初始化servlet的位置和名字 -->        <init-param>            <param-name>contextConfigLocation</param-name>            <param-value>classpath*:spring-mvc.xml</param-value>        </init-param>        <load-on-startup>1</load-on-startup>    </servlet>    <!-- servlet的请求url，可以采用*.do,这样jsp与css不会被拦截提高了性能 -->    <servlet-mapping>        <servlet-name>springMVC</servlet-name>        <url-pattern>*.do</url-pattern>    </servlet-mapping>    <welcome-file-list>        <welcome-file>welcome.jsp</welcome-file>    </welcome-file-list></web-app>

然后创建几个包和spring-mvc.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"    xmlns:context="http://www.springframework.org/schema/context"    xsi:schemaLocation="http://www.springframework.org/schema/beans     http://www.springframework.org/schema/beans/spring-beans-2.5.xsd    http://www.springframework.org/schema/context     http://www.springframework.org/schema/context/spring-context-2.5.xsd">    <!-- 控制器包扫描 -->    <context:component-scan base-package="controller"></context:component-scan>    <!-- 视图层解析 -->    <bean id="viewResolver"        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix" value="/WEB-INF/jsp/"></property>        <property name="suffix" value=".jsp"></property>    </bean></beans>

实体类user：

public class User{    private String userName;    private String password;    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;    }    //构造函数    public User(String userName,String password)    {        this.userName = userName;        this.password = password;    }}

充当控制器要有注解，然后需要扫描包。

@Controller@RequestMapping("/login")public class LoginController{    @RequestMapping("/name.do")    public ModelAndView loginByName(@RequestParam("userName") String name)    {        //调用服务层        if(LoginService.loginByName(name))        {            return new ModelAndView("/nameSuccess","name","s");        }        return new ModelAndView("/error");    }    @RequestMapping("/user.do")    public ModelAndView loginByUser(@RequestParam("userName") String name,@RequestParam("password") String password)    {        User user = new User(name,password);        //调用服务层        if(LoginService.loginByUser(user))        {            return new ModelAndView("/userSuccess","user",user);        }        return new ModelAndView("/error");    }}

调用的服务层：

public class LoginService{    public static boolean loginByName(String name)    {        if(name.equals("micro"))        {            return true;        }        return false;    }    public static boolean loginByUser(User user)    {        if(user.getUserName().equals("micro") && user.getPassword().equals("123456"))        {            return true;        }        return false;    }}

来设置欢迎页面，然后可以选择跳转到用user登录（输入姓名和密码）和name登录（只用输入名字）两个选项，注意这里跳转是无法跳转到WEB-INF目录下，只能通过controller去跳转到，href超链接也不行。最开始将页面放到WEB-INF下面一直无法正常跳转最后才知道是这个原因。如下两个UserLogin.jsp和NameLogin.jsp两个页面**不能放在**WEB-INF下面。：

<%@ 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>welcome page</title></head><body>欢迎你！    <a href="UserLogin.jsp">选择用户登陆</a>    <a href="NameLogin.jsp">选择名字登陆</a>    <a href="test.jsp">这里跳转</a></body></html>

UserLogin.jsp与NameLogin.jsp分别为：

<%@ 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>User登录</title></head><body><form action="login/user.do" method="post">用户名<input type = "text" name = "userName" value=""/>密码<input type = "password" name="password" value=""/><input type = "submit" value = "提交"/></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>用户名字登陆</title></head><body>    <form action="login/name.do" method="post">        <input type="text" name="userName" value=""/><input            type="submit" value="提交"/>    </form></body></html>

然后数据传输到controller，controller调用service然后完成数据的处理，返回一ModelAndView。ModelAndView有多个重载版本。

ModelAndView(String viewString,String objectName,Object obejct)
ModelAndViwe(String viewString)
比较常用。
如果返回到页面是个user对象，要在jsp页面取到private String userName.可以使用下面两种形式

${user.userName}${user.getUserName()}

两种方法都是调用的getter，但是第一种是隐式调用，并不是直接访问属性。
最后分别列出userSuccess和nameSuccess登录成功的页面，和验证失败的页面。由于视图解析器定义的前缀为WEB-INF/jsp/，后缀为.jsp。均放在该目录下。

<%@ 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>user登陆成功</title></head><body><h1>登陆成功</h1>userName=${user.userName}</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>name登陆成功</title></head><body><h1>登陆成功</h1>name=${name}</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>error page</title></head><body><h1>登录失败</h1></body></html>

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