Introduction

@PathVariable and @RequestParam are annotations in Spring MVC, these are used to capture the dynamic data which client send to our RESTful web service via a request URI.

@PathVariable captures values from URI path itself like below

http://localhost:8080/sayHi/Shiva

here Shiva is a path variable and which we are going to capture in below method.

@GetMapping(path = "/sayHi/{name}")
    public String pathVariableDemo(@PathVariable String name)
    {
        return "Hi "+name;
    }

output

Hi Shiva

@RequestParam captures values from query string like below

http://localhost:8080/sayHello?name=prasad

here name is a query param and which we are going to capture in below method

@GetMapping(path = "/sayHello")
    public String requestParamDemo(@RequestParam String name)
    {
        return "Hello "+name;
    }

output

Hello prasad

Note: You can use like @PathVariable("YYY") and @RequestParam("YYY"), if your URI element names and method parameter names are different. Here YYY is your URI element name.

Example:

http://localhost:8080/sayHello?name=prasad

I want to use name like "userName" in my code,

@GetMapping(path = "/sayHello")
    public String queryParam(@RequestParam("name") String userName)
    {
        return "Hello "+userName;
    }

Encoding

Because @PathVariable is extracting values from the URI path, it’s not encoded. On the other hand, @RequestParam is encoded.

Using the previous example, ab+c will return as-is:

http://localhost:8080/sayHi/ab+c
----
name: ab+c

But for a @RequestParam request, the parameter is URL decoded:

http://localhost:8080/sayHello?name=ab+c
----
name: ab c

We can use required attribute for both annotations to make optional.

public String pathVariableDemo(@PathVariable(required=false) String name)

public String requestParamDemo(@RequestParam(required=false) String name)

Thanks for reading :)

You can follow me at LinkedIn