Java Spring Boot 控制器处理无效 JSON

为了验证请求正文json，需要添加少量注释和判断.

1. Add dependency in pom.xml for the below annotations-个

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
            <version>3.1.1</version>
</dependency>

2. @Valid with Request Body个

    @PostMapping(value = "/shipdetails")
    public ResponseEntity acceptShip(@Valid @RequestBody Ship ship, 
                                     HttpServletRequest request)

3. @NotNull with the mandatory attributes个

    public class Ship implements Serializable {

      @NotNull(message = "The name is mandatory")
      @JsonProperty("Name")
      private String name;
      @JsonProperty("Owner")
      private String owner;

4. Additional null check before equals method个

Boolean checkShip(Ship ship) {
        if (StringUtils.isNotBlank(ship.getName()) 
            && ship.getName().equals("Queen Mary")) {
            // do something
        }

Output with Invalid json:个

Input个

    {
     "name_wrong":"test name",
     "owner":"Lloyds Shipping"
    }

Output:个 您将获得一个400 Bad Request状态，并且长错误堆栈跟踪包含如下内容

    "message": "Validation failed for object='ship'. Error count: 1",
"errors": [
    {
        "codes": [
            "NotNull.ship.name",
            "NotNull.name",
            "NotNull.java.lang.String",
            "NotNull"
        ],
        "arguments": [
            {
                "codes": [
                    "ship.name",
                    "name"
                ],
                "arguments": null,
                "defaultMessage": "name",
                "code": "name"
            }
        ],
        "defaultMessage": "The name is mandatory",
        "objectName": "ship",
        "field": "name",
        "rejectedValue": null,
        "bindingFailure": false,
        "code": "NotNull"
    }
]

Note: 使用我们的定制异常处理程序处理100异常的一些附加代码，以便验证将在正确格式化的响应中进行，而不是长时间的错误堆栈跟踪和控制状态代码，如下所示:

@ControllerAdvice
public class ValidationExceptionHandler {
    /**
     * For an invalid input, spring framework will throw an 
            MethodArgumentNotValidException exception
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<?> notValidInput(MethodArgumentNotValidException e) {
        Map<String,String> errorMap = e.getAllErrors()
                .stream()
                .collect(Collectors.toMap(x -> ((FieldError)x).getField(), 
                 b -> b.getDefaultMessage(),(p,q) -> p, LinkedHashMap::new));
        return new ResponseEntity<>(errorMap, HttpStatus.BAD_REQUEST);
    }
}

Formatted output for invalid json:个

{
    "name": "The name is mandatory"
}