Spring Boot之输入Bean验证@Valid应用场景总结

叁歲伎倆 2022-02-28 13:36 420阅读 0赞

## Validation应用场景 ##

在日常应用中，存在大量需要针对输入数据进行验证的应用场景，例如字符串的大小，ip地址验证，email格式验证等等各类情况。  
值得开心的是Spring Boot将这类场景进行了集成抽象，提供一个完整而且灵活的机制简化开发者在进行相关操作时的重复工作量。

## Maven引用 ##

在pom文件中添加如下信息：

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

就可以将相关Validation操作引入系统了。

## 基于@Valid验证JsonBean的输入实体Bean ##

定义Product实体类：

public class Product {
        //限购：1～5
        @Min(value = 1, message = "min Value is above zero")
        @Max(value = 10, message = "最大值不超过10")
        private int count;
    
        @Pattern(regexp = "^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$", message = "不符合IP规则")
        private String ipAddr;
    
        @Email(message = "email format error")
        @NotBlank
        private String email;
    
        @NotBlank(message = "name 不能为空")
        @Length(min=5, max = 10, message = "name长度在5到10个字符之间")
        private String name;
    }

Controller测试类：

@RestController
    @Slf4j
    public class TestController {
        @PostMapping("/test")
        public ResponseEntity<String> validateJsonBean(@Valid @RequestBody Product product) {
            return ResponseEntity.ok("valid id done");
        }
    }

输入测试数据：

{
    	"name": "asd",
    	"count":100,
    	"ipAddr": "12.2.1",
    	"email":""
    }

其相应结果信息如下：

{
        "timestamp": "2019-03-25T11:29:43.382+0000",
        "status": 400,
        "error": "Bad Request",
        "errors": [
            {
                "codes": [
                    "Min.product.count",
                    "Min.count",
                    "Min"
                ],
                "arguments": [
                    {
                        "codes": [
                            "product.count",
                            "count"
                        ],
                        "arguments": null,
                        "defaultMessage": "count",
                        "code": "count"
                    },
                    1
                ],
                "defaultMessage": "min Value is above zero",
                "objectName": "product",
                "field": "count",
                "rejectedValue": 0,
                "bindingFailure": false,
                "code": "Min"
            },
            {
                "codes": [
                    "NotBlank.product.email",
                    "NotBlank.email",
                    "NotBlank"
                ],
                "arguments": [
                    {
                        "codes": [
                            "product.email",
                            "email"
                        ],
                        "arguments": null,
                        "defaultMessage": "email",
                        "code": "email"
                    }
                ],
                "defaultMessage": "不能为空",
                "objectName": "product",
                "field": "email",
                "rejectedValue": null,
                "bindingFailure": false,
                "code": "NotBlank"
            },
            {
                "codes": [
                    "NotBlank.product.name",
                    "NotBlank.name",
                    "NotBlank"
                ],
                "arguments": [
                    {
                        "codes": [
                            "product.name",
                            "name"
                        ],
                        "arguments": null,
                        "defaultMessage": "name",
                        "code": "name"
                    }
                ],
                "defaultMessage": "name 不能为空",
                "objectName": "product",
                "field": "name",
                "rejectedValue": null,
                "bindingFailure": false,
                "code": "NotBlank"
            }
        ],
        "message": "Validation failed for object='product'. Error count: 3",
        "trace": "org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public org.springframework.http.ResponseEntity<java.lang.String> org.cjf.validationdemo.controller.TestController.validateJsonBean(org.cjf.validationdemo.beans.Product) with 3 errors: [Field error in object 'product' on field 'count': rejected value [0]; codes [Min.product.count,Min.count,Min]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [product.count,count]; arguments []; default message [count],1]; default message [min Value is above zero]] [Field error in object 'product' on field 'email': rejected value [null]; codes [NotBlank.product.email,NotBlank.email,NotBlank]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [product.email,email]; arguments []; default message [email]]; default message [不能为空]] [Field error in object 'product' on field 'name': rejected value [null]; codes [NotBlank.product.name,NotBlank.name,NotBlank]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [product.name,name]; arguments []; default message [name]]; default message [name 不能为空]] \n\tat org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:138)\n\tat org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:126)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:166)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:660)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:741)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)\n\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)\n\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\n\tat java.lang.Thread.run(Thread.java:748)\n",
        "path": "/test"
    }

从上述信息中可以发现，其status code为400，表示特定错误信息。在代码实现层面，其将抛出MethodArgumentNotValidException的异常，由Spring框架进行捕获，并转化为400的异常信息提示出来。  
在errors中展示了定制的错误提示信息. 这里没有定制错误的提示结果，使用了默认的error提示信息结果格式。

如果定制化错误信息的展示结果，会更新人性化一些，可读性会更好。具体示例如下：

@Data
    public class Product {
        //限购：1～5
        @Min(value = 1, message = "min Value is above zero")
        @Max(value = 10, message = "最大值不超过10")
        private int count;
    
        @Pattern(regexp = "^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$", message = "不符合IP规则")
        private String ipAddr;
    
        @Email(message = "email format error")
        @NotBlank
        private String email;
    
        @NotBlank(message = "name 不能为空")
        @Length(min=5, max = 10, message = "name长度在5到10个字符之间")
        private String name;
    }

## 基于@RequestParam和@PathVariable增加Valid ##

在Spring MVC应用中，允许使用上述各类的valid注解去验证@RequestParam和@PathVariable中定义的各类params。  
具体示例如下：

@Controller
    @Validated
    public class PathVariableController {
        @GetMapping("/valid/test/{id}")
        public ResponseEntity<String> handleTest(@PathVariable("id") @Max(10) int id,
                                                 @RequestParam("count") @Min(5) int count) {
            return ResponseEntity.ok("validation is done");
        }
    }

注意这里使用@Validated来修饰整个类，表示其中方法需要在method这个级别使用validation逻辑进行验证。  
针对@PathVariable/@RequestParam直接挂接注解的方式来修饰特定变量。  
注意一下，这里@Validated验证抛出的异常是javax.validation.ConstraintViolationException，在浏览器访问的过程中，其体会提示500的内部错误信息。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibGFkZS5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70]  
如果希望定制这个错误信息，可以将这个异常进行捕获，然后自行定义响应信息，具体做法如下：

@ControllerAdvice
    public class GlobalExceptionHandler {
        /**
         * Exception Handler.
         *
         * @param e
         * @return
         */
        @ExceptionHandler(ConstraintViolationException.class)
        @ResponseStatus(HttpStatus.BAD_REQUEST)
        ResponseEntity<String> handleConstraintViolationException(ConstraintViolationException e) {
            return new ResponseEntity<>("be valid due to validation error: " + e.getMessage(), HttpStatus.BAD_REQUEST);
        }
    }

这里ControllerAdvice是表示其为advice，用来接收controller的相关处理逻辑。  
@ExceptionHandler主要用来定义系统内部发生的特定异常的处理逻辑。  
在这里是将异常转化为了400的status code信息。

单元测试代码如下：

@RunWith(SpringRunner.class)
    @WebMvcTest(controllers={PathVariableController.class})
    @Slf4j
    public class PathVariableTestTest {
        @Autowired
        private MockMvc mockMvc;
    
        @Before
        public void before() throws Exception {
        }
    
        @After
        public void after() throws Exception {
        }
    
        @Test
        public void testValidParams() throws Exception {
            mockMvc.perform(get("/valid/test/{id}?count={count}", 9, 6))
                    .andExpect(status().isOk());
        }
    
        @Test
        public void testInValidParams() throws Exception {
            mockMvc.perform(get("/valid/test/{id}?count={count}", 123, 4))
                    .andExpect(status().isBadRequest());
        }
    }

在这个测试用例中，主要是基于Http Status Code来进行判断计算结果的正确性。

## 小结 ##

在本节中，主要测试了基于@Valid和@Validated两种模式下的验证逻辑，它们应用在不同场合，会抛出不同的异常信息，分别为：MethodArgumentNotValidException和javax.validation.ConstraintViolationException，前一个有Spring框架将其转化为400的Bad Request，而后者则直接定位为500的内部错误。

对于后者的异常信息，这里定义了异常的捕获逻辑，自行将其转为一个400的Bad Request。也希望大家可以从中学习如何来使用自定义的异常处理逻辑。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibGFkZS5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70]: /images/20220228/e52e07e5b2b343fc8afb13d95ecc1ac5.png