{"id":126412,"date":"2024-09-16T11:44:57","date_gmt":"2024-09-16T08:44:57","guid":{"rendered":"https:\/\/www.javacodegeeks.com\/?p=126412"},"modified":"2024-09-16T11:45:01","modified_gmt":"2024-09-16T08:45:01","slug":"spring-validator-validation-example","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/spring-validator-validation-example.html","title":{"rendered":"Spring Validator Validation Example"},"content":{"rendered":"

1. Introduction<\/h2>\n

Spring Validation Framework<\/a> includes the Validator<\/a> interface that handles data validation. It is used to implement custom validation logic. In this example, I will create a Spring MVC rest controller and implement the Spring validator interface to validate the create request.<\/p>\n

2. Setup<\/h2>\n

In this step, I will create a gradle project along with lombok<\/a> and Junit libraries.<\/p>\n

build.gradle<\/em><\/span><\/p>\n

plugins {\n\tid 'java'\n\tid 'org.springframework.boot' version '3.3.3'\n\tid 'io.spring.dependency-management' version '1.1.6'\n}\n\ngroup = 'org.zheng.demo.validator'\nversion = '0.0.1-SNAPSHOT'\n\njava {\n\ttoolchain {\n\t\tlanguageVersion = JavaLanguageVersion.of(17)\n\t}\n}\n\nconfigurations {\n\tcompileOnly {\n\t\textendsFrom annotationProcessor\n\t}\n}\n\n\nrepositories {\n\tmavenCentral()\n}\n\ndependencies {\n\timplementation 'org.springframework.boot:spring-boot-starter-web'\n\tcompileOnly 'org.projectlombok:lombok'\n\tannotationProcessor 'org.projectlombok:lombok'\n\ttestImplementation 'org.springframework.boot:spring-boot-starter-test'\n\ttestRuntimeOnly 'org.junit.platform:junit-platform-launcher'\n}\n\ntasks.named('test') {\n\tuseJUnitPlatform()\n}\n<\/pre>\n
3. Implement Spring Validator Interface<\/h2>\n
<\/a>3.1 UserData<\/h3>\n
In this step, I will create a UserData<\/code> class which has three data fields: userId<\/code>, name<\/code>, and email<\/code>. The lombok<\/code> annotations: @Data<\/code> and @NoArgsConstructor<\/code> are used to reduce boilerplate code.<\/p>\n
UserData<\/em><\/span><\/p>\n
package org.zheng.demo.validator.model;\n\nimport lombok.Data;\nimport lombok.NoArgsConstructor;\n\n@Data\n@NoArgsConstructor\npublic class UserData {\t\n\tprivate String userId;\n\tprivate String name;\n\tprivate String email;\n}\n<\/pre>\n
<\/a>3.2 UserDataValidator<\/h3>\n
In this step, I will create a UserDataValidator<\/code> class that implements the Validator<\/code> interface from the org.springframework.validation<\/code> package. It overrides both supports<\/code> and validate<\/code> methods for the UserData<\/code> class defined in step 3.1<\/a>.<\/p>\n
UserDataValidator.java<\/em><\/span><\/p>\n
package org.zheng.demo.validator.model;\n\nimport org.springframework.stereotype.Component;\nimport org.springframework.validation.Errors;\nimport org.springframework.validation.ValidationUtils;\nimport org.springframework.validation.Validator;\n\n@Component\npublic class UserDataValidator implements Validator {\n\n\t@Override\n\tpublic boolean supports(Class<?> clazz) {\n\t\treturn UserData.class.isAssignableFrom(clazz);\n\t}\n\n\t@Override\n\tpublic void validate(Object target, Errors errors) {\n\t\tValidationUtils.rejectIfEmptyOrWhitespace(errors, \"userId\", \"missing userId.\");\n\t\tValidationUtils.rejectIfEmptyOrWhitespace(errors, \"name\", \"missing name.\");\n\t}\n}\n<\/pre>\n