重定向和转发
ModelAndView
设置ModelAndView对象，根据view的名称、视图解析器跳转到指定的页面
页面：{视图解析器前缀}+ viewName +{视图解析器后缀}
- springmvc-servlet.xml
<!--视图解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!--前缀--> <property name="prefix" value="/WEB-INF/jsp/"/> <!--后缀--> <property name="suffix" value=".jsp"/> </bean>
- Controller类
//实现了Controller类说明这就是控制器 public class ControllerTest1 implements Controller { @Override public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception { //创建模型和视图对象 ModelAndView modelAndView = new ModelAndView(); 封装数据,向模型添加属性msg与值，可以在jsp页面取出、渲染 modelAndView.addObject("msg","ControllerTest1"); //视图跳转 modelAndView.setViewName("test"); //返回视图模型对象 return modelAndView; } }
ServletAPI
设置ServletAPI，不需要视图解析器
通过HttpServletResponse进行输出、重定向、转发
@Controller public class ModelTest1 { @RequestMapping("/m1/t1") public String test(HttpServletRequest request, HttpServletResponse response){ HttpSession session = request.getSession(); System.out.println(session.getId()); return "test"; } }
SpringMVC
通过SpringMVC实现转发和重定向，不需要视图解析器
- 转发
@Controller public class ModelTest1 { @RequestMapping("/m1/t1") public String test(Model model){ //转发 model.addAttribute("msg","ModelTest"); return "/WEB-INF/jsp/test.jsp"; //return "forward:/WEB-INF/jsp/test.jsp"; } }
- 重定向
@Controller public class ModelTest1 { @RequestMapping("/m1/t1") public String test(Model model){ //重定向 model.addAttribute("msg","ModelTest"); return "redirect:/index.jsp"; } }
数据处理
接受请求参数及数据回显，处理提交数据
处理提交数据
- 提交的域名称和处理方法的参数名
一致
@Controller @RequestMapping("/user") public class UserController { @GetMapping("/t1") public String test(String name, Model model) { //接受前端参数 System.out.println("接收到前端的参数为：" + name); //将放回结果传递给前端 model.addAttribute("msg",name); //跳转视图 return "test"; } }
- 提交的域名称和处理方法的参数名
不一致
@RequestParam("username")
@Controller @RequestMapping("/user") public class UserController { @GetMapping("/t1") public String test(@RequestParam("username") String name, Model model) { //接受前端参数 System.out.println("接收到前端的参数为：" + name); //将放回结果传递给前端 model.addAttribute("msg",name); //跳转视图 return "test"; } }
- 提交是一个对象（参数名和对象名需要一致，否则返回Null）
- User类
@Data @AllArgsConstructor @NoArgsConstructor public class User { private int id; private String name; private int age; }
- UserController类
@Controller @RequestMapping("/user") public class UserController { @RequestMapping("/t2") public String test2(User user){ System.out.println(user); return "test"; } } //输出结果：User(id=1, name=weishuo, age=18)
数据显示到前端
ModelAndView
//实现了Controller类说明这就是控制器 public class ControllerTest1 implements Controller { @Override public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception { //创建模型和视图对象 ModelAndView modelAndView = new ModelAndView(); 封装数据,向模型添加属性msg与值，可以在jsp页面取出、渲染 modelAndView.addObject("msg","ControllerTest1"); //视图跳转 modelAndView.setViewName("test"); //返回视图模型对象 return modelAndView; } }
Model
@Controller @RequestMapping("/user") public class UserController { @GetMapping("/t1") public String test(@RequestParam("username") String name, Model model) { //接受前端参数 System.out.println("接收到前端的参数为：" + name); //将放回结果传递给前端 model.addAttribute("msg",name); //跳转视图 return "test"; } }
ModelMap
@Controller @RequestMapping("/user") public class UserController { @RequestMapping("/t3") public String test3(ModelMap map){ map.addAttribute("msg","HELLO ModelMap"); return "test"; } }
总结
- Model 只有寥宴几个方法只适合用于储存数据，简化了新手对于Model对象的操作和理解
- ModelMap 继承了 LinkedMap，除了实现了自身的一些方法，同样的继承LinkedMap 的方法和特性
- ModelAndview 可以在储存数据的同时，可以进行设置返回的逻辑视图，进行控制展示层的跳转
过滤器解决乱码
Javaweb过滤器
- EncodingController类
@Controller public class EncodingController { @GetMapping("/e/t1") public String test1(String name, Model model, HttpServletRequest request) throws UnsupportedEncodingException { request.setCharacterEncoding("utf-8"); System.out.println(name); model.addAttribute("msg",name); return "test"; } }
- EncodingFilter过滤器
public class EncodingFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { servletRequest.setCharacterEncoding("utf-8"); servletResponse.setCharacterEncoding("utf-8"); filterChain.doFilter(servletRequest, servletResponse); } @Override public void destroy() { } }
- web.xml配置过滤器
<filter> <filter-name>encoding</filter-name> <filter-class>com.wei.filter.EncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/</url-pattern> </filter-mapping>
SpringMVC过滤器
SpringMVC中提供了过滤器，可以在web.xml中配置
- EncodingController类
@Controller public class EncodingController { @RequestMapping("/e/t1") public String test1(String name, Model model, HttpServletRequest request) throws UnsupportedEncodingException { request.setCharacterEncoding("utf-8"); System.out.println(name); model.addAttribute("msg",name); return "test"; } }
- web.xml配置SpringMVC乱码过滤器
<!--配置SpringMVC乱码过滤器--> <filter> <filter-name>encoding</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
🌼 结语：创作不易，如果觉得博主的文章赏心悦目，还请——
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