How to check the parameters of webplus

order

This paper mainly studies how to verify the parameters of webplus

Using javax.validation

domain

import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;

public class User {

    @Min(1)
    private long id;

    @NotEmpty
    private String name;

    @Min(20)
    private int age;
    //...
}

Handling exceptions through onErrorResume

Form form submission

    /**
     * curl -i -X POST -d 'id=-1&name=a&age=10' http://localhost:8080/user/validate-mono
     *
     * curl -i -X POST -d 'id=2&name=a&age=10' http://localhost:8080/user/validate-mono
     *
     * curl -i -X POST -d 'id=2&name=a&age=30' http://localhost:8080/user/validate-mono
     * @param user
     * @return
     */
    @PostMapping("/validate-mono")
    public Mono<String> formValidate(@Validated Mono<User> user) {
        return user
                .map(u -> "Hello " + u.getName())
                .onErrorResume(WebExchangeBindException.class, e -> Mono.just(bindingResult2String(e.getBindingResult())));
    }

post json

    /**
     * curl -i -H "Content-Type: application/json" -X POST -d '{"id":-11,"name":"a"}' http://localhost:8080/user/validate-mono-json-body
     *
     * curl -i -H "Content-Type: application/json" -X POST -d '{"id":12,"name":"a","age":30}' http://localhost:8080/user/validate-mono-json-body
     * @param user
     * @return
     */
    @PostMapping(value = "/validate-mono-json-body",produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    @ResponseBody
    public Mono<String> requestBodyValidate(@Validated @RequestBody Mono<User> user) {

        return user
                .map(u -> "Hello " + u.getName())
                .onErrorResume(WebExchangeBindException.class, e -> Mono.just(bindingResult2String(e.getBindingResult())));
    }

Notice that here catch lives in WebExchangeBindException

Handling WebExchangeBindException with ExceptionHandler

ExceptionHandler

    @ExceptionHandler(WebExchangeBindException.class)
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    @ResponseBody
    public String handleBindException(WebExchangeBindException bindException) {
        return bindingResult2String(bindException.getBindingResult());
    }

from form submission

    /**
     * curl -i -X POST -d 'id=-1&name=a&age=10' http://localhost:8080/user/validate-mono
     *
     * curl -i -X POST -d 'id=2&name=a&age=10' http://localhost:8080/user/validate-mono
     *
     * curl -i -X POST -d 'id=2&name=a&age=30' http://localhost:8080/user/validate-mono
     * @param user
     * @return
     */
    @PostMapping(value = "/validate-mono",produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public Mono<String> formValidate(@Validated Mono<User> user) {
        return user
                .map(u -> "Hello " + u.getName());
    }

Note that we need to mark "produces = mediatype. Application" JSON "utf8" value, otherwise it will report 406 Not Acceptable

post json

    /**
     * curl -i -H "Content-Type: application/json" -X POST -d '{"id":-11,"name":"a"}' http://localhost:8080/user/validate-mono-json-body
     *
     * curl -i -H "Content-Type: application/json" -X POST -d '{"id":12,"name":"a","age":30}' http://localhost:8080/user/validate-mono-json-body
     * @param user
     * @return
     */
    @PostMapping(value = "/validate-mono-json-body",produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    @ResponseBody
    public Mono<String> requestBodyValidate(@Validated @RequestBody Mono<User> user) {

        return user
                .map(u -> "Hello " + u.getName());
    }

Note that the onErrorResume is not used to handle the WebExchangeBindException here, but is handed over to the ExceptionHandler

Manual calibration

Although javax.validation is convenient, the specific business scenario is very complex. It is not a simple single field verification. Some need to be associated with the verification. At this time, javax.validation is powerless. You may need to write the verification manually at this time.

    /**
     * curl -i -X POST -d 'id=-1&name=a&age=10' http://localhost:8080/user/manual-validate
     *
     * curl -i -X POST -d 'id=2&name=a&age=-1' http://localhost:8080/user/manual-validate
     * @param user
     * @return
     */
    @PostMapping(value = "/manual-validate",produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public Mono<String> manualValidate(Mono<User> user){
        return user.flatMap(u -> {
            if(u.getAge() < 0){
                return Mono.error(new RuntimeException("age < 0"));
            }else{
                return Mono.just("success");
            }
        });
    }

Summary

By using javax.validation automatic verification and Mono.error manual verification, you can basically handle most weblux parameter verification scenarios.

doc

Keywords: JSON curl WebFlux Spring

Added by koolswans on Sun, 05 Apr 2020 13:39:34 +0300

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