springboot2.1入门系列二 hibernate validator

怼烎@ 2022-04-15 01:11 288阅读 0赞

本文为Spring Boot2.1系列的第二篇，代码可以从github下载 [https://github.com/yinww/demo-springboot2.git][https_github.com_yinww_demo-springboot2.git]

对数据验证的工作经常由前端工程师完成，但是代码重复繁琐，并且即使有前端的验证也不能放松后端对数据的验证工作，否则可能存在数据安全性的问题，代码示意如下：

本文介绍Spring Boot的后台验证技术hibernate validator，内容包括：

1、hibernate validator验证

2、hibernate validator自定义验证

3、hibernate validator验证的国际化

一、hibernate validator验证

Spring Boot2.1自带hibernate validator包，不需要额外单独引入。

参考 [上一篇文章][Link 1] 访问[https://start.spring.io/][https_start.spring.io] 创建工程demo002，Group输入com.yinww.demo.springboot2.demo002 ， Artifact输入demo0022，Dependencies选择Web和Thymeleaf，然后点击Generate Project按钮下载zip包，解压缩并将其作为Maven Project引入到Eclipse环境中。

新建JavaBean类User，写明对每个属性的验证要求，如不能为空等等

package com.yinww.demo.springboot2.demo002.domain;
    
    import javax.validation.constraints.Email;
    import javax.validation.constraints.NotBlank;
    
    public class User {
    
    	@NotBlank(message = "用户名不能为空")
    	private String username;
    
    	@NotBlank(message = "密码不能为空")
    	private String password;
    
    	@Email(message = "邮箱格式错误")
    	private String email;
    	
        // getter and setter ...
    }

新建一个返回值的类ResultEntity

package com.yinww.demo.springboot2.demo002.domain;
    
    public class ResultEntity {
    
    	private int status;
    	private Object data;
    	private String msg;
    	
    	public ResultEntity() {
    	}
    	
    	public ResultEntity(int status) {
    		this.status = status;
    	}
    	
    	public ResultEntity(int status, Object data) {
    		this.status = status;
    		this.data = data;
    	}
        // getter and setter...
    }

创建一个Controller类TestController，其中save方法的@Validated注解就是给user对象做数据校验的

package com.yinww.demo.springboot2.demo002.controller;
    
    import org.springframework.http.HttpStatus;
    import org.springframework.stereotype.Controller;
    import org.springframework.validation.annotation.Validated;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.yinww.demo.springboot2.demo002.domain.ResultEntity;
    import com.yinww.demo.springboot2.demo002.domain.User;
    
    @Controller
    public class TestController {
    
    	@RequestMapping(value={"/", "index.html"})
    	public String index() {
    		return "index";
    	}
    
    	@RequestMapping(value="save")
    	@ResponseBody
    	public Object save(@Validated User user) {
    		return new ResultEntity(HttpStatus.OK.value(), user);
    	}
    }

编写一个全局的异常处理类TestExceptionHandler 以捕捉异常并返回到前端

package com.yinww.demo.springboot2.demo002.handler;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Set;
    
    import javax.validation.ConstraintViolation;
    import javax.validation.ConstraintViolationException;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.http.HttpStatus;
    import org.springframework.validation.BindException;
    import org.springframework.validation.BindingResult;
    import org.springframework.validation.ObjectError;
    import org.springframework.web.bind.MethodArgumentNotValidException;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.yinww.demo.springboot2.demo002.domain.ResultEntity;
    
    @ControllerAdvice
    public class TestExceptionHandler {
    
    	private static final Logger log = LoggerFactory.getLogger(TestExceptionHandler.class);
    
        @ExceptionHandler(Exception.class)
        @ResponseBody
        public ResultEntity handleException(Exception e){
            log.error(e.getMessage(), e);
    
            BindingResult result = null;
            if (e instanceof MethodArgumentNotValidException){
                result = ((MethodArgumentNotValidException) e).getBindingResult();
            } else if (e instanceof BindException){
                result = ((BindException) e).getBindingResult();
            } else if (e instanceof ConstraintViolationException){
                Set<ConstraintViolation<?>> constraintViolations = ((ConstraintViolationException) e).getConstraintViolations();
                List<String> errors = new ArrayList<>();
                for (ConstraintViolation<?> violation : constraintViolations) {
                	errors.add(violation.getMessage());
                }
                return new ResultEntity(HttpStatus.OK.value(), errors);
            }
            
            if (result != null) {
            	List<String> errors = new ArrayList<>();
                for (ObjectError error : result.getAllErrors()) {
                	errors.add(error.getDefaultMessage());
                }
                return new ResultEntity(HttpStatus.BAD_REQUEST.value(), errors);
            }
    
            return new ResultEntity(HttpStatus.BAD_REQUEST.value());
        }
    }

创建一个Thymeleaf模板文件index.html

运行Spring Boot工程demo002，在浏览器中访问 [http://localhost:8080/][http_localhost_8080]

![20181119222238549.png][]

点击提交按钮，如果验证结果有问题，那么页面返回验证出错的内容

{"status":400,"data":["密码不能为空","用户名不能为空"],"msg":null}

前端工程师可以对上面的json内容进行解析，展示成想要的效果。

二、自定义验证

给User类添加一个身份证号码的属性，验证身份证号码的格式是否正确，required用于说明是否必填，相关的逻辑都需要在后面的自定义验证类中实现

@IDConstraint(required = false, message = "身份证号码格式错误")
    private String idCard;

创建注解验证约束类 IDConstraint

package com.yinww.demo.springboot2.demo002.validator;
    
    import java.lang.annotation.Documented;
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    import javax.validation.Constraint;
    import javax.validation.Payload;
    
    @Documented
    @Retention(RetentionPolicy.RUNTIME)
    @Target({ElementType.PARAMETER, ElementType.FIELD, ElementType.METHOD})
    @Constraint(validatedBy=IDValidator.class)
    public @interface IDConstraint {
    	boolean required();
    	
    	String message();
    	
    	Class<?>[] groups() default {};
    	
    	Class<? extends Payload>[] payload() default {};
    }

创建验证的逻辑类IDValidator

package com.yinww.demo.springboot2.demo002.validator;
    
    import javax.validation.ConstraintValidator;
    import javax.validation.ConstraintValidatorContext;
    
    public class IDValidator implements ConstraintValidator<IDConstraint, String> {
    	private boolean required;
    	
    	@Override
    	public void initialize(IDConstraint idConstraint) {
    		this.required = idConstraint.required();
    	}
    
    	@Override
    	public boolean isValid(String value, ConstraintValidatorContext context) {
    		if(value == null || value.trim().length() == 0) {
    			return !required;
    		}
    		
    		String regIdcard = "^\\d{6}(19|20)\\d{2}((1[0-2])|0\\d)([0-2]\\d|30|31)\\d{3}[\\d|X|x]$";
    		return value.matches(regIdcard);
    	}
    
    }

修改Thymeleaf模板index.html form表单中加上身份证号码输入框

<form action="save" method="post">
       <table>
         <tr>
           <td>用户名</td>
           <td><input name="username"></td>
         </tr>
         <tr>
           <td>密码</td>
           <td><input type="password" name="password"></td>
         </tr>
         <tr>
           <td>邮箱</td>
           <td><input name="email"></td>
         </tr>
         <tr>
           <td>身份证号码</td>
           <td><input name="idCard"></td>
         </tr>
         <tr>
           <td><input type="submit"> </td>
         </tr>
       </table>
    </form>

运行Spring Boot工程demo002，在浏览器中访问 [http://localhost:8080/][http_localhost_8080]

身份证号码输入框中输入1234，点击提交按钮，如果验证结果有问题，那么页面返回验证出错的内容

{"status":400,"data":["密码不能为空","用户名不能为空","身份证号码格式错误"],"msg":null}

前端工程师可以对上面的json内容进行解析，展示成想要的效果。

三、hibernate validator的国际化

国际化，简单说就是需要将内容抽取到多语言的properties文件中。

修改application.properties文件，添加内容：

spring.messages.basename=i18n/messages

在resources目录下创建i18n目录，在i18n目录下创建messages.properties、messages\_zh\_CN.properties和messages\_en\_US.properties 三个文件。messages\_zh\_CN.properties文件中输入：

error.username=用户名不能为空
    error.password=密码不能为空
    error.email=邮箱格式错误
    error.idcard=身份证号码格式错误

messages\_en\_US.properties文件中输入：

error.username=username cannot be empty
    error.password=password cannot be empty
    error.email=email invalid
    error.idcard=idcard invalid

messages.properties内容空着就行，但是不能没有这个文件。

User类修改为：

public class User {
    
    	@NotBlank(message = "{error.username}")
    	private String username;
    
    	@NotBlank(message = "{error.password}")
    	private String password;
    
    	@Email(message = "{error.email}")
    	private String email;
    	
    	@IDConstraint(required = false, message = "{error.idcard}")
    	private String idCard;
    
        // getter and setter
    }

Demo002Application类修改为

@SpringBootApplication
    public class Demo002Application {
    
    	@Autowired
        private MessageSource messageSource;
    
    	public static void main(String[] args) {
    		SpringApplication.run(Demo002Application.class, args);
    	}
    	
    	@Bean
        public Validator getValidator() throws Exception {
            LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
            validator.setValidationMessageSource(messageSource);
            return validator;
        }
    
        @Bean
        public LocaleResolver localeResolver() {
            SessionLocaleResolver slr = new SessionLocaleResolver();
            slr.setDefaultLocale(Locale.CHINA);
    //        slr.setDefaultLocale(Locale.US);
            return slr;
        }
    
    }

运行Spring Boot工程demo002，在浏览器中访问 [http://localhost:8080/][http_localhost_8080]  也能正常验证。将上面代码中的Locale设置为Locale.US即可显示messages\_en\_US.properties文件中定义的英文的验证错误内容。

本文内容到此结束，更多内容可关注公众号：

![2018111718160012.jpg][]

[https_github.com_yinww_demo-springboot2.git]: https://github.com/yinww/demo-springboot2.git
[Link 1]: https://blog.csdn.net/bowei026/article/details/84171233
[https_start.spring.io]: https://start.spring.io/
[http_localhost_8080]: http://localhost:8080/
[20181119222238549.png]: /images/20220415/be05a50b3c4342c3a85dd8bb7078eae2.png
[2018111718160012.jpg]: /images/20220415/8c3c0abba6bd4d8a90d218d7a86110a6.png