SpringMVC--获取请求参数

1、通过的ServletAPI获取

只需要在控制器的方法的形参位置设置HTTPRequest request 类型的形参就i可以在控制器方法种使用request对象获取请求参数

@RequestMapping("/servletAPI")public String getByServletAPI(HttpServletRequest request){HttpSession session = request.getSession();String username = request.getParameter("username");String password = request.getParameter("password");System.out.println("username = " + username + "," + "password = " +  password);return "success";

2、通过控制器方法的形参获取请求参数

前端页面

<form th:action="@{/param}" method="post">用户名：<input type="text" name="username"><br>密码：<input type="password" name="password"><br><input type="submit" value="登录">
</form>

@RequestMapping("/param")
public String getParam(String username,String password){ System.out.println("username:"+username+",password:"+password);return "success";
}

* 只需要在控制器方法的形参位置，设置一个形参，形参的名字和请求参数的名字一致即可

3、通过@RequestParam获取请求参数

@RequestParam是将请求参数和控制器方法的形参创建映射关系

http://localhost:8080/springmvc_rest/param?password=123

@RequestMapping("/param")
public String getParam(@RequestParam(value = "username",required = true,        defaultValue = "hello")String username, String password){System.out.println("username:" + username + ",password:" + password);return "success";
}

@RequestParam注解的属性：
value：设置和形参绑定的请求参数的名字
required:设置是否必须传输value所对应的请求参数

默认值为true，表示value所对应的请求参数必须传输否则页面报错 Required String parameter 'xxx' is not present
若设置为false，则表示value所对应的请求参数不是必须传输，如果此时获取该参数的值，则为nul

defaultValue：设置当没有传输value所对应的请求参数时，为形参设置的默认值，此时和required属性值无关

4、通过@RequestHeaher获取请求参数

@RequestParam是将请求头信息和控制器方法的形参创建映射关系


@RequestMapping("/param")public String getParam(String username, String password,@RequestHeader("referer") String referer){System.out.println("username = " + username + "," + "password = " +  password);System.out.println("referer = " + referer);return "success";}

5、通过@CookieValue获取请求参数

@CookieValue是将cookie数据和控制器方法的形参创建映射关系

@RequestMapping("/param")public String getParam(String username, String password,@CookieValue("JSESSIONID") String jsessionId){System.out.println("username = " + username + "," + "password = " +  password);System.out.println("jsessionId = " + jsessionId);return "success";}

返回结果

6、通过pojo获取请求参数

先创建实体类

package com.pojo;
public class User {private  Integer id;private String username;private String password;public User() {    }public User(Integer id, String username, String password) {this.id = id;this.username = username;this.password = password;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}@Overridepublic String toString() {return "User{" +"id=" + id + ", username='" + username + '\'' +", password='" + password + '\'' +'}';}
}