Java -- 工具类 BeanValidator

1、配置 maven 依赖

<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>1.1.0.Final</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>5.2.4.Final</version>
</dependency>

#注意在springboot下，validation-api不能引入，否则会报错误

2、工具类

package com.sample.common.utils;

import org.springframework.util.CollectionUtils;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.Map;
import java.util.Set;

public class BeanValidator {

    public static <T> boolean validate(T object, Map<String, Object> model){
        Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
        Set<ConstraintViolation<T>> constraintViolations = validator.validate(object);
        if (CollectionUtils.isEmpty(constraintViolations)){
            return true;
        }else{
            for (ConstraintViolation<T> cv : constraintViolations) {
                String property = cv.getPropertyPath().toString();
                model.put("message", property+cv.getMessage());
            }
            return false;
        }
    }
}

3、实体 -- User.java

package com.sample.modules.web.model;

import org.hibernate.validator.constraints.NotEmpty;

public class User {

    public interface loginValid{}

    @NotEmpty
    private String username;

    //若填写了groups，则该参数验证只在对应验证规则下启用
    @NotEmpty(groups = {loginValid.class})
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

4、使用方式 -- 工具类

package com.sample.modules.web.controller;

import com.sample.common.utils.BeanValidator;
import com.sample.modules.web.model.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.HashMap;
import java.util.Map;

@Controller
public class TestController {

    @RequestMapping(value = "/validator")
    @ResponseBody
    public Map<String, Object> validator(User user){
        Map<String, Object> result = new HashMap<>();
        BeanValidator.validate(user, result);
        return result;
    }

}

5、使用方式 -- 注解 @Validated，并分组

package com.sample.modules.web.controller;

import com.sample.modules.web.model.User;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;

@RestController
public class UserController {

    //此处会校验 username 和 password 非空
    @RequestMapping(value = "/login")
    public String login(@Validated(value = User.loginValid.class) User user){
        return "success";
    }

    //此处会校验 username 非空
    @RequestMapping(value = "/register")
    public String register(@Valid User user){
        return "success";
    }
}

6、自定义校验注解

package com.sample.common.validate;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = IsQQEmailImpl.class)
public @interface IsQQEmail {

    String message() default "email is invalid";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    @Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
    @Retention(RUNTIME)
    @Documented
    public @interface List {
        IsQQEmail[] value();
    }
}

package com.sample.common.validate;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class IsQQEmailImpl implements ConstraintValidator<IsQQEmail, String> {

    @Override
    public void initialize(IsQQEmail constraintAnnotation) {

    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        return true;
    }
}