spring mvc
在https://mvnrepository.com/查找maven库里spring的包.
围绕DispatchServlet来设计,所有web请求都会到这个类.
从spring 2.5,java5或以上的用户就可以使用基于注解的control声明方式.
老的方式:
1. 在pom.xml里导入Spring依赖
<dependencies> <dependency> <groupId>org.springframeworkgroupId> <artifactId>spring-webartifactId> <version>5.3.14version> dependency> <dependency> <groupId>org.springframeworkgroupId> <artifactId>spring-webmvcartifactId> <version>5.3.14version> dependency> <dependency> <groupId>commons-logginggroupId> <artifactId>commons-loggingartifactId> <version>1.2version> dependency> <dependency> <groupId>javax.servlet.jspgroupId> <artifactId>javax.servlet.jsp-apiartifactId> <version>2.3.3version> <scope>providedscope> dependency> <dependency> <groupId>javax.servletgroupId> <artifactId>javax.servlet-apiartifactId> <version>4.0.1version> <scope>providedscope> dependency> dependencies>
2. 在web.xml中配置DispatchServelet,MVC的配置文件,以及DispatchServlet的mapping.
<servlet> <servlet-name>springDispatcherServletservlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class> <init-param> <param-name>contextConfigLocationparam-name> <param-value>classpath:springmvc.xmlparam-value> init-param> <load-on-startup>1load-on-startup> servlet> <servlet-mapping> <servlet-name>springDispatcherServletservlet-name> <url-pattern>/url-pattern> servlet-mapping>
3. 在resources下添加文件springmvc.xml,并添加
<?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: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-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name = "prefix" value="/WEB-INF/views/">property> <property name = "suffix" value = ".jsp">property> bean> <bean id="/hello" class="com.ptc.springmvc.handler.HelloWorld"/> beans>
4.创建controller
package com.ptc.springmvc.handler; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; public class HelloWorld implements Controller { public ModelAndView handleRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws Exception { //模型和视图 ModelAndView mv = new ModelAndView(); //封装对象,放在ModelAndView中,Model mv.addObject("msg","HelloSpringMVC!"); //封装要跳转的视图,放在ModelAndView中 mv.setViewName("hello"); //: /WEB-INF/jsp/hello.jsp return mv; } }
5. 在WEB-INF/jsp下创建hello.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
Title
${msg}
新的方式:
1. 在pom.xml里导入Spring依赖
<dependencies> <dependency> <groupId>org.springframeworkgroupId> <artifactId>spring-webartifactId> <version>5.3.14version> dependency> <dependency> <groupId>org.springframeworkgroupId> <artifactId>spring-webmvcartifactId> <version>5.3.14version> dependency> <dependency> <groupId>commons-logginggroupId> <artifactId>commons-loggingartifactId> <version>1.2version> dependency> <dependency> <groupId>javax.servlet.jspgroupId> <artifactId>javax.servlet.jsp-apiartifactId> <version>2.3.3version> <scope>providedscope> dependency> <dependency> <groupId>javax.servletgroupId> <artifactId>javax.servlet-apiartifactId> <version>4.0.1version> <scope>providedscope> dependency> dependencies>
2. 在web.xml中配置DispatchServelet,MVC的配置文件,以及DispatchServlet的mapping.
<servlet> <servlet-name>springDispatcherServletservlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class> <init-param> <param-name>contextConfigLocationparam-name> <param-value>classpath:springmvc.xmlparam-value> init-param> <load-on-startup>1load-on-startup> servlet> <servlet-mapping> <servlet-name>springDispatcherServletservlet-name> <url-pattern>/url-pattern> servlet-mapping>
3.在resources下添加文件springmvc.xml,并添加
<?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: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-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <context:component-scan base-package="com.ptc.springmvc">context:component-scan> <mvc:default-servlet-handler/> <mvc:annotation-driven/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name = "prefix" value="/WEB-INF/views/">property> <property name = "suffix" value = ".jsp">property> bean> beans>
4.创建controller
package com.ptc.springmvc.handler; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class HelloWorld { /** *1. 使用RequestMapping注解来映射请求的URL * 2. 返回值会通过视图解析器解析为实际的物理视图, 对于InternalResourceViewResolver视图解析器,会做如下解析 * 通过prefix+returnVal+suffix 这样的方式得到实际的物理视图,然后会转发操作 * "/WEB-INF/views/success.jsp" * @return * */ @RequestMapping("/helloworld") public String hello(Model model){ //封装数据 model.addAttribute("msg","hello springmvc!"); return "success"; } }
5.创建success.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
Title
${msg}
转发和重定向
1. 使用HttpServletResponse来实现转发和重定向
package com.ptc.springmvc; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import javax.annotation.RegEx; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; @Controller public class Redirection { @RequestMapping("/test1") public void test1(HttpServletRequest request, HttpServletResponse response) throws IOException { response.getWriter().println("test1....."); } @RequestMapping("/test2") public void test2(HttpServletRequest request,HttpServletResponse response) throws IOException { response.sendRedirect("/springmvc-04-redirection/views/test2.jsp"); } @RequestMapping("/test3") public void test3(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException { request.setAttribute("msg","test3....."); request.getRequestDispatcher("/WEB-INF/views/test3.jsp").forward(request,response); } }
2. 使用Springmvc来转发和重定向 -无需视图解析器
要去掉springmvc.xml里配置的视图解析器
这里可以看到forward可以使用WEB-INF下面的jsp,而redirect不能.
WEB-INF是Java的WEB应用的安全目录。所谓安全就是客户端无法访问,只有服务端可以访问的目录。
页面放在WEB-INF目录下面,这样可以限制访问,提高安全性.如JSP,html
既然WEB-INF是安全目录,客户端无法访问,而重定向就相当于用户直接从客户端访问了的路径,自然就不可以啦,只有程序内部转发的时候才能转发到WEB-INF下的JSP。
package com.ptc.springmvc; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class RedirectionMVC { @RequestMapping("/rm/t1") public String test1(){ //转发 return "/views/test2.jsp"; } @RequestMapping("rm/t2") public String test2(Model model){ model.addAttribute("msg","test3..."); //转发2 return "forward:/WEB-INF/views/test3.jsp"; } @RequestMapping("rm/t3") public String test3(){ //重定向 return "redirect:/views/test2.jsp"; } }
处理提交数据
1. 提交的域名称和处理方法的参数名称一致
提交数据:http://localhost:8080//springmvc_05_receivedata/hello?name=roger
package com.ptc.receivedata; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class ReceiveData { @RequestMapping("/hello") public String hello(String name) { System.out.println("name>>>>>>>>>>>" + name); return "hello"; } }
后台打印
2. 提交的域名称和处理方法的参数名称不一致
提交数据:http://localhost:8080//springmvc_05_receivedata/hello?username=roger
使用@RequestParam("username")来指定name对应的域名称.
@Controller public class ReceiveData { //@RequestParam("username") @RequestMapping("/hello2") public String hello2(@RequestParam("username") String name) { System.out.println("name2>>>>>>>>>>>" + name); return "hello"; } }
3. 提交一个对象
提交数据:http://localhost:8080//springmvc_05_receivedata/test?id=1&name=roger&age=36
创建一个实体类
package com.ptc.dojo; public class User { private int id; private String name; private int age; public User(int id, String name, int age) { this.id = id; this.name = name; this.age = age; } public User() { } public int getId() { return id; } public void setId(int id) { this.id = id; } 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; } }
UserController.java 使用User对象参数,传过来的参数的跟它的属性名字一一对应.
package com.ptc.receivedata; import com.ptc.dojo.User; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class UserController { @RequestMapping("/test") public String test(User user) { System.out.println("id:" + user.getId() + "|name:" + user.getName() + "|age:" + user.getAge()); return "hello"; } }
结果
数据显示到前端
1. 通过ModelAndView
public class TestController { @RequestMapping("/test") public ModelAndView test() { ModelAndView mv = new ModelAndView(); mv.addObject("msg","test!!!"); mv.setViewName("test"); return mv; } @RequestMapping("/test1") public ModelAndView test1() { ModelAndView mv = new ModelAndView(); mv.addObject("msg","redirect test!!!"); mv.setViewName("redirect:/views/test.jsp"); return mv; } }
2. 通过ModelMap
@RequestMapping("/test2")
public String test2(@RequestParam("username") String name, ModelMap modelMap) {
modelMap.addAttribute("name",name);
return "test2";
}
3. 通过Model
@RequestMapping("/helloworld")
public String hello(Model model){
//封装数据
model.addAttribute("msg","hello springmvc!");
return "success";
}
乱码问题
1.重现乱码
form.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
Title
EncodingController.java
package com.ptc.receivedata; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PostMapping; @Controller public class EncodingController { @PostMapping("/e/t1") public String test1(String name,Model model){ model.addAttribute("name",name); return "test2"; } }
输入url:http://localhost:8080//springmvc_05_receivedata/form.jsp
提交之后出现乱码: