4.Spring-MVC 映射和请求参数乱码

学习5中映射方式，常用的有1,3,4，5，Ant风格作为了解。
（一）标准ＵＲＬ映射
user.jsp

@Controller
@RequestMapping("/user")
public class UserController {
（一）标准ＵＲＬ映射
@RequestMapping("/usertest")
// @RequestMapping(value="/usertest")
//@RequestMapping(value={"/usertest",“usertest2”})//页面多个值

public String user(Model model){ //1
model.addAttribute(“name”,“张三”);
return “showUser”;
}
（二）占位符映射
@RequestMapping(value=“usertest7/{id}”)//占位符映射7 后台显示1
public String user7(@PathVariable(“id”) Integer id){
System.out.println(id);
return “showUser”;
}
}
（三）4、限制请求方法映射
/@RequestMapping(value="/usertest",method = {RequestMethod.GET,RequestMethod.POST})

//@RequestMapping(value="/usertest",method = RequestMethod.POST)//报错

//@RequestMapping(value="/usertest",method = RequestMethod.GET)//默认 Request method ‘GET’ not supported
public String user(Model model){ //1
model.addAttribute(“name”,“张三”);
return “showUser”;
}
}
（四）5、限制参数映射
//方式一：不带id
@RequestMapping(value=“usertest2” ,params=“id”) //2
public String user2(Model model){
model.addAttribute(“name”,“张三”);
return “showUser”;
}

//方式二：带id
@RequestMapping(value=“usertest2” ,params=“id”)//与页面一致 2
public String user2(Model model,int id){
model.addAttribute(“name”,“张三”);
System.out.println(id);
return “showUser”;
}

//方式三：id参数与页面不一致，还能识别，需要加上@RequestParam(“类中参数”)
@RequestMapping(value=“usertest2” ,params=“uid”)//报错 此id!=uid 2
public String user2(Model model,@RequestParam(“uid”) int id){
model.addAttribute(“name”,“张三”);
System.out.println(id);
return “showUser”;
}
//方式四：id值与页面要求不一致
限定请求参数映射（id!=1）3

@RequestMapping(value=“usertest3” ,params=“id!=1”)//与页面一致 3
public String user3(Model model, int id){
model.addAttribute(“name”,“张三”);
System.out.println(id);
return “showUser”;
}

//方式五：类中不能是id,其他都可以
限定请求参数映射(参数!id）4

@RequestMapping(value=“usertest3” ,params="!id")//4
public String user3(Model model, int aid){
model.addAttribute(“name”,“张三”);
System.out.println(aid);
return “showUser”;
}
//方式六参数!id，类中不给id参数
标准映射5（参数!id，类中不给id参数）

@RequestMapping(value=“usertest3” ,params="!id")//5 不给id
public String user3(Model model){
model.addAttribute(“name”,“张三”);
return “showUser”;
}
//方式七：请求中没有参数id,类中参数有id,系统不报错
@RequestMapping(value=“usertest5”)//6
public String user5(Model model,@RequestParam(value=“id”,required=false)Integer id){
model.addAttribute(“name”,“张三”);
System.out.println(id);
return “showUser”;
}

showUser.jsp
${name}
乱码中添加web.xml配置

index.jsp CharacterEncondingFilter org.springframework.web.filter.CharacterEncodingFilter encoding UTF-8 forceEncoding true CharacterEncondingFilter /*