What is restful style and its four specific implementation forms

One 、 background
When we developed the project before , We generally don't pay attention to the way in which the front end requests data from the back end , No matter what comes from your front end get Request or post request , That is, no matter what kind of request , We can all use @RequestMapping To deal with .
But if during the project development , The boss of the group stipulates that we must clearly deal with what kind of request our front-end is , yes get still post? yes put still delete？ At this time, in fact, we will take restful Style to handle our front-end requests . meanwhile ,restful Can also be realized ： The request path is the same ( For example, several request paths are "/user/test") Under the circumstances , We can ask for different methods , To match different back-end interfaces .
Two 、Restful Four request implementations of
restful There are four main implementations , That is, the four corresponding to us http Request mode ：
（1）GET: get data
（2）POST: Add data
（3）PUT: Modifying data
（4）DELETE: Delete data

In the project ,GET,POST,PUT,DELETE The four request methods correspond to @GetMapping、PostMapping、@PutMapping、@DeleteMapping. Each annotation performs its own duties , You can only do your part , namely @GetMapping Can only handle get request , The other three requests cannot be processed .

1、GET That is, the database select operation : The request will send a request to the database to query data , To get information , It is only used to query the data , Not modify 、 Add or update data , It doesn't affect the content of the resource . No matter how many operations , The contents of the database will not change .

2、PUT That is, the database update operation : The request is to send data to the server , And change the message , It is used to modify the content of data , But the data will not be added , No matter how many times PUT operation , The database will not add or reduce data .

3、POST That is, the database insert operation : Request the same PUT The request is similar to , They all send data to the server , But the request will add data , Almost all of the current commit operations use POST Requested （ For example, user registration ）.

4、DELETE That is, the database delete operation : A request is used to delete a resource .

POST Mainly Acting on a collection of resources （url）, and PUT Acting primarily on a specific resource （url/xxx）. Such as URL It can be determined on the client side , Then you can use PUT, Otherwise, use POST.

One URL Address , It is used to describe resources on a network , and HTTP Medium GET,POST,PUT,DELETE The four request methods correspond to the query of this resource in the database , increase , Change , Delete 4 Operations .

3、 ... and 、 Code instance

@RestController
@RequestMapping("/user/test")
public class JoblevelController {
    
 
    @Autowired
    private JoblevelService joblevelService;
 
    @ApiOperation(value = " Get all titles ")
    @GetMapping("/")
    public List<Joblevel> getAllJobLevels(){
    
        return joblevelService.list();
    }
 
    @ApiOperation(value = " Add title ")
    @PostMapping("/")
    public RespBean addJobLevel(@RequestBody Joblevel joblevel){
    
        if(joblevelService.save(joblevel)){
    
            return RespBean.success(" Title added successfully ");
        }
        return RespBean.error(" Failed to add professional title ");
    }
 
    @ApiOperation(value = " Modify the title ")
    @PutMapping("/")
    public RespBean updateJobLevel(@RequestBody Joblevel joblevel){
    
        if(joblevelService.updateById(joblevel)){
    
            return RespBean.success(" Title Modified successfully ");
        }
        return RespBean.error(" Failed to modify professional title ");
    }
 
    @ApiOperation(value = " Delete professional title ")
    @DeleteMapping("/{id}")
    public RespBean deleteJobLevelById(@PathVariable Integer id){
    
        if(joblevelService.removeById(id)){
    
            return RespBean.success(" The professional title was deleted successfully ");
        }
        return RespBean.error(" Failed to delete professional title ");
    }
 
    @ApiOperation(value = " Delete professional titles in batch ")
    @DeleteMapping("/")
    public RespBean deleteJobLevelByIds(Integer[] ids){
    
        if(joblevelService.removeByIds(Arrays.asList(ids))){
    
            return RespBean.success(" Batch deletion of professional titles succeeded ");
        }
        return RespBean.error(" Failed to delete professional titles in batch ");
    }
}