1. 结果跳转方式
1.1 ModelAndView
设置ModelAndView对象，根据view的名称和视图解析器跳转到指定的页面（视图解析器前缀 + viewName + 视图解析器后缀）
<!-- 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>
对应的Controller控制器
public class ControllerTest1 implements Controller {
public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
//返回一个模型视图对象
ModelAndView mv = new ModelAndView();
mv.addObject("msg","ControllerTest1");
mv.setViewName("test");
return mv;
}
}
1.2 ServletAPI
通过设置ServletAPI，不需要视图解析器
-
通过HttpServletResponse进行输出
-
通过HttpServletResponse进行重定向
-
通过HttpServletResponse实现转发
@Controller public class ResultGo { @RequestMapping("/result/t1") public void test1(HttpServletRequest req, HttpServletResponse rsp) throws IOException { rsp.getWriter().println("Hello"); } @RequestMapping("/result/t2") public void test2(HttpServletRequest req, HttpServletResponse rsp) throws IOException { rsp.sendRedirect("/index.jsp"); } @RequestMapping("/result/t3") public void test3(HttpServletRequest req, HttpServletResponse rsp) throws Exception { //转发 req.setAttribute("msg","/result/t3"); req.getRequestDispatcher("/WEB-INF/jsp/test.jsp").forward(req,rsp); } }
1.3 SpringMVC
通过SpringMVC来实现转发和重定向，视图解析器可以使用也可以不使用
@Controller
public class ResultSpringMVC2 {
@RequestMapping("/rsm2/t1")
public String test1(){
//转发
return "test";
}
@RequestMapping("/rsm2/t2")
public String test2(){
//重定向
return "redirect:/index.jsp";
//hello.do为另一个请求/
//return "redirect:hello.do";
}
}
2. 数据处理
2.1 处理提交数据
-
提交时候的参数名和处理方法的参数名一致，则会自动匹配
@RequestMapping("/hello") public String hello(String name){ System.out.println(name); return "hello"; } -
提交时候的参数名和处理方法的参数名不一致，需要在方法的参数列表中使用
@RequestParam注解进行手动绑定//@RequestParam("username") : username 提交的域的名称 . @RequestMapping("/hello") public String hello(@RequestParam("username") String name){ System.out.println(name); return "hello"; } -
提交的是一个对象
- 如果提交的是一个对象，则参数直接使用对象即可
@RequestMapping("/user") public String user(User user){ System.out.println(user); return "hello"; }
3. 数据显示到前端
3.1 通过ModelAndView
public class ControllerTest1 implements Controller {
public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
// 返回一个模型视图对象
ModelAndView mv = new ModelAndView();
mv.addObject("msg","ControllerTest1");
mv.setViewName("test");
return mv;
}
}
3.2 通过ModelMap
@RequestMapping("/hello")public String hello(@RequestParam("username") String name, ModelMap model){ //封装要显示到视图中的数据 //相当于req.setAttribute("name",name); model.addAttribute("name",name); System.out.println(name); return "hello";}
3.3 通过Model
@RequestMapping("/ct2/hello")public String hello(@RequestParam("username") String name, Model model){ //封装要显示到视图中的数据 //相当于req.setAttribute("name",name); model.addAttribute("msg",name); System.out.println(name); return "test";}
3.4 三种方式对比
- Model 只有寥寥几个方法只适合用于储存数据，简化了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
4. 乱码问题
我们可以通过修改配置文件web.xml中的过滤器，spring自带CharacterEncodingFilter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>
也可以使用自定义的过滤器
package top.linzeliang.filter;import javax.servlet.*;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.util.Map;/** * 解决get和post请求 全部乱码的过滤器 */public class GenericEncodingFilter implements Filter { @Override public void destroy() { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { //处理response的字符编码 HttpServletResponse myResponse=(HttpServletResponse) response; myResponse.setContentType("text/html;charset=UTF-8"); // 转型为与协议相关对象 HttpServletRequest httpServletRequest = (HttpServletRequest) request; // 对request包装增强 HttpServletRequest myrequest = new MyRequest(httpServletRequest); chain.doFilter(myrequest, response); } @Override public void init(FilterConfig filterConfig) throws ServletException { }}//自定义request对象，HttpServletRequest的包装类class MyRequest extends HttpServletRequestWrapper { private HttpServletRequest request; //是否编码的标记 private boolean hasEncode; //定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰 public MyRequest(HttpServletRequest request) { super(request);// super必须写 this.request = request; } // 对需要增强方法 进行覆盖 @Override public Map getParameterMap() { // 先获得请求方式 String method = request.getMethod(); if (method.equalsIgnoreCase("post")) { // post请求 try { // 处理post乱码 request.setCharacterEncoding("utf-8"); return request.getParameterMap(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } else if (method.equalsIgnoreCase("get")) { // get请求 Map<String, String[]> parameterMap = request.getParameterMap(); if (!hasEncode) { // 确保get手动编码逻辑只运行一次 for (String parameterName : parameterMap.keySet()) { String[] values = parameterMap.get(parameterName); if (values != null) { for (int i = 0; i < values.length; i++) { try { // 处理get乱码 values[i] = new String(values[i] .getBytes("ISO-8859-1"), "utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } } } hasEncode = true; } return parameterMap; } return super.getParameterMap(); } //取一个值 @Override public String getParameter(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); if (values == null) { return null; } return values[0]; // 取回参数的第一个值 } //取所有值 @Override public String[] getParameterValues(String name) { Map<String, String[]> parameterMap = getParameterMap(); String[] values = parameterMap.get(name); return values; }}
