Spring MVC @Valid annotation with Example

Hey guys in this post we will discuss @Valid annotation in Spring MVC with example.

Table of Contents

Overview

@Valid annotation is nothing to do with Spring because it is not a part of the Spring framework. It is a part of Bean Validation specification but @Valid is very old and derives all the way from JSR 303.

What it does is basically checks if the data that you send to the controller method is valid or not. If the data is valid then it will not do anything but if the data is not valid then it will throw an exception MethodArgumentNotValidException.

@PostMapping("/test")
public String test (@Valid @RequestBody Customer customer) {
   //logic
}

Watch the video

Example on @Valid annotation

Let’s understand @Valid annotation with an example by creating a simple spring boot project

Create spring boot project

There are many different ways to create a spring boot application, you can follow the below articles to create one –

>> Create spring boot application using Spring initializer
>> Create spring boot application in Spring tool suite [STS]
>> Create spring boot application in IntelliJ IDEA

Add the maven dependencies

Open pom.xml and add the following dependencies –

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.3</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>in.bushansirgur</groupId>
	<artifactId>validannotation</artifactId>
	<version>v1</version>
	<name>validannotation</name>
	<description>Spring boot valid annotation</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-validation</artifactId>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

spring-boot-starter-web dependency for building web applications using Spring MVC. It uses the tomcat as the default embedded container. spring-boot-devtools dependency for automatic reloads or live reload of applications.spring-boot-starter-validation dependency is for the bean validation, it is like a reference implementation of the bean validation API.

Create an entity class

Create Customer.java inside the in.bushansirgur.springboot.entity package and add the following content

package in.bushansirgur.springboot.entity;

import javax.validation.constraints.NotNull;

public class Customer {
	
	@NotNull
	private String name;
	
	@NotNull(message = "Location should not be null")
	private String location;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getLocation() {
		return location;
	}

	public void setLocation(String location) {
		this.location = location;
	}
}

This is just a plain old java class that has private fields, setters, and getters.@NotNull validates that the annotated property value is not null.

Create a Rest controller

Create CustomerController.java inside the in.bushansirgur.springboot.controller package and add the following content

package in.bushansirgur.springboot.controller;

import javax.validation.Valid;

import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import in.bushansirgur.springboot.entity.Customer;

@RestController
public class CustomerController {
	
	@PostMapping("/test")
	public String test (@Valid @RequestBody Customer customer) {
		return "Success";
	}
}

We will annotate @Valid annotation to the controller method parameter to validate the Bean. Before binding the values to the Bean Customer, if the field name or location is empty/null then @Valid annotation will throw an exception MethodArgumentNotValidException.

Run the app

Run the application using the below maven command –

mvn spring-boot:run

Open the rest-client and enter the following URL with the following request body

http://localhost:8080/test

Output:

{
    "timestamp": "2021-03-06T08:25:07.245+00:00",
    "status": 400,
    "error": "Bad Request",
    "trace": "org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public java.lang.String in.bushansirgur.springboot.controller.CustomerController.test(in.bushansirgur.springboot.entity.Customer): [Field error in object 'customer' on field 'location': rejected value [null]; codes [NotNull.customer.location,NotNull.location,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [customer.location,location]; arguments []; default message [location]]; default message [Location should not be null]] \n\tat org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:139)\n\tat org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:170)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:962)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:652)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:733)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346)\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:887)\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1684)\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",
    "message": "Validation failed for object='customer'. Error count: 1",
    "errors": [
        {
            "codes": [
                "NotNull.customer.location",
                "NotNull.location",
                "NotNull.java.lang.String",
                "NotNull"
            ],
            "arguments": [
                {
                    "codes": [
                        "customer.location",
                        "location"
                    ],
                    "arguments": null,
                    "defaultMessage": "location",
                    "code": "location"
                }
            ],
            "defaultMessage": "Location should not be null",
            "objectName": "customer",
            "field": "location",
            "rejectedValue": null,
            "bindingFailure": false,
            "code": "NotNull"
        }
    ],
    "path": "/test"
}

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