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Yiğit Erkal
Yiğit Erkal

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Spring - @PathVariable

#spring #java #programming #http

A Spring annotation called @PathVariable specifies that a method parameter should be tied to a URI template variable.

@GetMapping("/api/products/{id}") @ResponseBody public String getProductsById(@PathVariable String id) { return "ID: " + id; }
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A simple GET request to /api/products/{id} will invoke getProductsById with the extracted id value:

http://localhost:8080/api/products/333 ---- ID: 333
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We may also specify the path variable name:

@GetMapping("/api/products/{id}") @ResponseBody public String getProductsById(@PathVariable("id") String productId) { return "ID: " + productId; }
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One Class to Rule Them All 🪄

Best practice to handle not required path variables is to combine with Java Optional. In this way, you are both able to handle exceptions and the logic.

@GetMapping(value = { "/api/products", "/api/products/{id}" }) @ResponseBody public String getProducts(@PathVariable Optional<String> id) { if (id.isPresent()) { return "ID: " + id.get(); } else { return "ID missing"; } }
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Now if we don't specify the path variable id in the request, we get the default response:

http://localhost:8080/api/employeeswithoptional ---- ID missing
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