Introduce the difference between @getmapping and @postmapping in detail

One 、 Preface

Want to know @GetMapping and @PostMapping The difference between , First of all, I need to understand @RequestMapping annotation .
understand @RequestMapping Please click me for comments

Two 、@GetMapping and @PostMapping The difference between

（1）@GetMapping yes @RequestMapping(method = RequestMethod.GET) Combined notes of abbreviations , Is used to HTTP Of get Request a method annotation that maps to a specific handler .

（2）@PostMapping yes @RequestMapping(method = RequestMethod.POST) Combined notes of abbreviations , Is used to HTTP Of post Request a method annotation that maps to a specific handler .

（3） Let's take a look at @GetMapping Source code

The most important thing in the above figure is this line of code ：

@RequestMapping( method = {RequestMethod.GET} )

This line of code explains @GetMapping Namely @RequestMapping Attached get Request method . in other words @GetMapping It's one that can only be used to deal with http Of get Requested comment , More specific , This is the only thing I can do , Unlike @RequestMapping Can handle a variety of http Request .
meanwhile , You can see @GetMapping This annotation yes spring4.3 Version to introduce , At the same time, the introduction of @PostMapping、@PutMapping、@DeleteMapping and @PatchMapping, altogether 5 A note .

（4） In general, our development may use @RequestMapping（method=RequestMethod.×××）, because @RequestMapping You can directly replace the above two annotations , But the above two notes are not a substitute for @RequestMapping.
Similar combined annotations are also mentioned above ：@PutMapping、@DeleteMapping、@PatchMapping Three annotations .

3、 ... and 、 summary
To sum up ：@PostMapping、@GetMapping、@PutMapping、@DeleteMapping、@PatchMapping Both can be used. @RequestMapping Instead of , If you are afraid of making mistakes in mapping , It can be used in a unified way @RequestMapping（method=RequestMethod.×××）, Of course, there are disadvantages in writing like this , General all use @RequestMapping, It is not convenient for others to read and understand the code ！ It is still recommended to write separately , Develop good code habits ！