java_springMVC_获取get请求的参数

青旅半醒 2022-05-25 04:19 573阅读 0赞

1. 获取get请求的参数

Get请求的参数的获取有三种方式。

**方式一：使用getParameter**

@RequestMapping("/getUrlParam")

**public** String getUrlParam(HttpServletRequest request)\{

String id = request.getParameter("id");

System.***out***.println("id:"\+id);

**return** "";

[http://localhost:8080/firstSpringMVC/user/getUrlParam?id=45][http_localhost_8080_firstSpringMVC_user_getUrlParam_id_45]

输出：

**方式二：直接使用参数**

正如上面第一个例子，直接在controller的函数中添加参数，只要参数名和url中的参数名一样，就可以直接得到解析。

@RequestMapping(method = RequestMethod.***GET***, value = "/dologin")

**public** String dologin(

HttpServletRequest request, HttpServletResponse response,

String username, String password)\{

System.***out***.println("dologin : " + username + " - " + password);

**return** "";

[http://localhost:8080/firstSpringMVC/user/dologin?username='abc'&password='123'][http_localhost_8080_firstSpringMVC_user_dologin_username_abc_password_123]

**方式三：使用RequestParam注解**

@RequestMapping("/getUrlParamByRequestParam")

**public** String getUrlParamByRequestParam(

@RequestParam(required=**false**, defaultValue="-1") Integer userID)\{

System.***out***.println("userID:"\+userID);

**return** "";

其中required为false表示此参数为非必需参数;

defaultValue为默认值。

[http://localhost:8080/firstSpringMVC/user/getUrlParamByRequestParam?userID=667][http_localhost_8080_firstSpringMVC_user_getUrlParamByRequestParam_userID_667]

输出：userID:667

[http://localhost:8080/firstSpringMVC/user/getUrlParamByRequestParam][http_localhost_8080_firstSpringMVC_user_getUrlParamByRequestParam]

输出：userID:-1

当required为true时。表示此参数是必需的，因此必需有值。如果此时把defaultValue去掉，在url中不写此参数，访问时就会报错

[http_localhost_8080_firstSpringMVC_user_getUrlParam_id_45]: http://localhost:8080/firstSpringMVC/user/getUrlParam?id=45
[http_localhost_8080_firstSpringMVC_user_dologin_username_abc_password_123]: http://localhost:8080/firstSpringMVC/user/dologin?username='%20rel=
[http_localhost_8080_firstSpringMVC_user_getUrlParamByRequestParam_userID_667]: http://localhost:8080/firstSpringMVC/user/getUrlParamByRequestParam?userID=667
[http_localhost_8080_firstSpringMVC_user_getUrlParamByRequestParam]: http://localhost:8080/firstSpringMVC/user/getUrlParamByRequestParam