如何在 Springboot 应用程序中获取 HTTPServletRequest

Question

To get the request URL, found below approaches in stack overflow.

1st approach:

@Autowired
private HttpServletRequest request;

public void getURL(){
String url=request.getRequestURL().toString();
}

2nd approach:

public void getURL(){
String url=ServletUriComponentsBuilder.fromCurrentRequestUri().toUriString();
}

3rd approach:

public void getURL(){
HttpServletRequest request= 
((ServletRequestAttributes)RequestContextHolder.currentRequestAttributes()).getRequest();
String url=request.getRequestURL().toString();
}

I am confused which one to use to get the request URL in the spring boot application.

if i go with 3rd approach, then should i need to create bean of RequestContextListener in Configuration class as shown below?

@Bean
public RequestContextListener requestContextListener(){
return new RequestContextListener();
}

Answer 1

Actually it is very simple. Create a class that is annotated as @RestController and in it create a method that is handling your mapping. In that method list HttpServletRequest request as your parameter. That's it, in this method you will get it as parameter and can use it. Below is one of my working examples that does just that.

@RestController
@RequestMapping("/upload")
public class UploadTestController {
    @PostMapping
    public ResponseEntity<String> uploadTest(HttpServletRequest request) {
        try {
            String lengthStr = request.getHeader("content-length");
            int length = TextUtils.parseStringToInt(lengthStr, -1);
            if(length > 0) {
                byte[] buff = new byte[length];
                ServletInputStream sis =request.getInputStream();
                int counter = 0;
                while(counter < length) {
                    int chunkLength = sis.available();
                    byte[] chunk = new byte[chunkLength];
                    sis.read(chunk);
                    for(int i = counter, j= 0; i < counter + chunkLength; i++, j++) {
                        buff[i] = chunk[j];
                    }
                    counter += chunkLength;
                    if(counter < length) {
                        TimeUtils.sleepFor(5, TimeUnit.MILLISECONDS);
                    }
                }
                Files.write(Paths.get("C:\\Michael\\tmp\\testPic.jpg"), buff);
            }
        } catch (Exception e) {
            System.out.println(TextUtils.getStacktrace(e));
        }
        return ResponseEntity.ok("Success");
    }

}

Answer 2

In springboot, if use are using @Restcontroller, HttpServletRequest already exist in first paramester of controler method

@PostMapping(value = "/abc")
public ResponseEntity<?> abcMethod(HttpServletRequest req){
   // Do anything with HttpServletRequest here
}