Spring MVC数据处理和乱码问题详解

@RequestMapping("/hello")
public String hello(String name){
 System.out.println(name);
 return "hello";
}

//@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";
}

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class User {
 private int id;
 private String name;
 private int age;
}

@RequestMapping("/user")
public String user(User user){
 System.out.println(user);
 return "hello";
}

 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;
 }
}

@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";
}

@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";
}

<form action="/e/t" method="post">
 <input type="text" name="name">
 <input type="submit">
</form>

@Controller
public class EncodingController {
 
 @RequestMapping("/e/t")
 public String test1(String name, Model model) {
 System.out.println(name);
 //获取表达提交的值
 model.addAttribute("msg", name);
 //跳转到test页面显示输入的值
 return "test";
 }
}

<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>

<Connector URIEncoding="utf-8" port="8080" protocol="HTTP/1.1"
 connectionTimeout="20000"
 redirectPort="8443" />

 <!--配置SpringMVC的乱码过滤，注意/*-->
 <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>

/**
* 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;
 }
}