轻轻松松学习SpringBoot2：第十五篇： 获取访问参数

一：PathVariable

@RestController
@RequestMapping("/o")
public class DemoController {
    @Value("${c}")
    private String c;
    @RequestMapping(value = "/c/{id}",method=RequestMethod.GET)
    String Say(@PathVariable("id") Integer myId){
        return "the id is:"+myId;
    }
}

或者

@RestController
@RequestMapping("/o")
public class DemoController {
    @Value("${c}")
    private String c;
    @RequestMapping(value = "/{id}/c",method=RequestMethod.GET)
    String Say(@PathVariable("id") Integer myId){
        return "the id is:"+myId;
    }
}

启动服务，执行结果如下

二：RequestParam

@RestController
@RequestMapping("/o")
public class DemoController {
    @Value("${c}")
    private String c;
    @RequestMapping(value = "/c",method=RequestMethod.GET)
    String Say(@RequestParam("id") Integer myId){
        return "the id is:"+myId;
    }
}

执行结果如下

如果参数不传则会页面报错，这不是我们想看到的，这块我们需要做如下处理

@RestController
@RequestMapping("/o")
public class DemoController {
    @Value("${c}")
    private String c;
    @RequestMapping(value = "/c",method=RequestMethod.GET)
    String Say(@RequestParam(value="id",required = false,defaultValue = "999") Integer myId){
        return "the id is:"+myId;
    }
}

我们默认，如果没有获取到id，则用默认值999代替