介绍
本篇文章是关于利用对象来接收表单提交的参数.
这样可以避免代码过于臃肿,在项目中是很普遍使用的一种方法.
在本篇文章中,我将根据依据spring MVC的运作方式来一步步的给搞出来.
spring MVC框架思路
spring MVC的详见
http://www.cnblogs.com/dssjustdoit/articles/9387847.html
http://www.cnblogs.com/dssjustdoit/articles/9389087.html
http://www.cnblogs.com/dssjustdoit/articles/9390395.html
http://www.cnblogs.com/dssjustdoit/articles/9392477.html
http://www.cnblogs.com/dssjustdoit/articles/9395355.html
http://www.cnblogs.com/dssjustdoit/articles/9396743.html
目录
注:是在大模块中建的小模块(感觉有点废话了)
执行流程
STEP 1 导入相关dependency和指定jdk版本(pom.xml)
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.dss</groupId> <artifactId>learnspringmvc1</artifactId> <version>1.0-SNAPSHOT</version> <modules> <module>06form</module> </modules> <packaging>pom</packaging> <name>learnspringmvc1 Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.0.4.RELEASE</version> </dependency> </dependencies> <build> <finalName>learnspringmvc1</finalName> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.0.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.7.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.20.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.0</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build> </project>
STEP 2在浏览器中访问到jsp的表单提交页面(addStudent.jsp)
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <form method="post" action="/student/add.do"> 姓名:<input name="name"> <br> 年龄:<input name="age"> <br> <input type="submit" value="提交"> </form> </body> </html>
注:这个当然也是通过tomcat来访问到这个表单页面的(但用不着spring MVC框架的咚咚),如下图
注:那么当我点击提交按钮后,就出触发action,于是就产生了/student/add.do 这个url,于是乎,浏览器就会回应这个请求,访问tomcat.
STEP 3 访问tomcat(查询*.do的url配置)(web.xml)
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <!--字符编码过滤器--> <!--最好配置在其他过滤器之前，因为过滤器的执行顺序是根据web.xml中的顺序一致--> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <!--手动指定字符编码--> <init-param> <!--因为当前filter中的成员变量叫做encoding，所以此处必须也写成encoding--> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> <!--强制指定字符编码，即使在request或者response中设置了字符编码，那么也会为其强制使用当前设置的字符编码--> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- 注册spring MVC中央控制器 --> <servlet> <servlet-name>springMVC</servlet-name> <!-- spring MVC中的核心控制器 --> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springMVC</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> </web-app>
注:那么我在web.xml中配置了*.do的配置,就将url传给了DispatcherServlet中央调控器.中央调控器会在<init-param>中找到初始文件,即springmvc.xml.
STEP 4 将url传给springmvc.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" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!--注解驱动--> <mvc:annotation-driven/> <!-- 注册组件扫描器 --> <context:component-scan base-package="com.dss.*"/> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans>
注:我在springmvc.xml配置文件中配置了注册组件扫描器和,我就可以在com.dss包下面扫描所有的注释,找到controller
STEP 5 找到controller(StudentController.java)
package com.dss.controller; import com.dss.bean.Student; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; @Controller @RequestMapping("/student") public class StudentController { @RequestMapping("/add.do") public ModelAndView addStudent(Student student) throws Exception{ ModelAndView mv = new ModelAndView(); mv.addObject("name",student.getName()); mv.addObject("age",student.getAge()); mv.setViewName("studentInfo"); return mv; } }
注:找到Controller注释, RequestMapping注释意思是只要是以"/student"开头且以"/add.do"为结尾的url命令,都会交给这个controller来处理.
同时,我也在addStudent方法中传入了Student这个参数,那么controller就会把接收到的name和age传给student.getName()和student.getAge(),在接下来,将信息传给studentInfo.jsp文件
最后返回ModelAndView给中央控制器.
STEP 6 Student.java
package com.dss.bean; public class Student { private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
注:这个Student.java和提交表单的jsp是没有直接关系的,只是在controller中把值传给了它,这也就是本篇文章所做的主要工作,使用对象来接收表单提交的参数!!
STEP 7 studentInfo.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> 姓名：${name} <br> 年龄：${age} </body> </html>
注:在studentInfo.jsp文件接收传来的值.然后随ModelAndView返回给DispatcherServlet,再由DispatcherServlet将之相应给浏览器.
结论
这样,通过对象来接收表单提交的参数,当参数过多时,就可以避免在controller类中写一大堆的咚咚,避免代码过于臃肿.