springboot框架get访问总结与演示

一、从路径中获取字段
以下都通过Postman进行测试

@RequestMapping(path = "/{city_id}/{user_id}", method = RequestMethod.GET)
public Object findUser(@PathVariable("city_id") String cityId, @PathVariable("user_id") String userId
) {
params.clear();
params.put("cityId", cityId);
params.put("userId", userId);
return params;
}
```![在这里插入图片描述](https://img-blog.csdnimg.cn/20200729213113356.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3MTMzNTU0,size_16,color_FFFFFF,t_70)1、city_id与user_id分别对应路径中的100和200
2、@PathVariable("city_id") String cityId 将city_id转换成cityId
3、method = RequestMethod.GET 将请求方式设置成get ,路径中的get是类上的路由
**二、@GetMapping请求**
@GetMapping(value="/v1/page_user1")
public Object pageUser(int  from, int size ){
params.clear();
params.put("from", from);
params.put("size", size);
return params;
}
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200729213847917.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3MTMzNTU0,size_16,color_FFFFFF,t_70)@GetMapping = @RequestMapping(method = RequestMethod.GET)
通过get方式请求，将请求参数拼在路径后面，注意路径后的参数名应与接收请求的方法入参一致
**三、参数默认**
@GetMapping(value="/v1/page_user2")
public Object pageUserV2(@RequestParam(defaultValue="10",name="page") int  from, int size ){
params.clear();
params.put("from", from);
params.put("size", size);
return params;
}
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200729220046288.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3MTMzNTU0,size_16,color_FFFFFF,t_70)![在这里插入图片描述](https://img-blog.csdnimg.cn/20200729220142733.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3MTMzNTU0,size_16,color_FFFFFF,t_70)
使用@RequestParam(defaultValue="10",name="page")来设置参数接收默认值，如果使用page传递，将可传递预想的值，否则使用默认值10
**四、通过request获取参数**
@GetMapping("/v1/test_request")
public Object testRequest(HttpServletRequest request){
params.clear();
String id = request.getParameter("id");
params.put("id", id);
return params;
}
直接在参数添加HttpServletRequest 将会自动装载，并能获取session