添加依赖

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

常用的几个注解

自己做一个注解

参考已有注解

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

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * The annotated element must not be {@code null}.
 * Accepts any type.
 *
 * @author Emmanuel Bernard
 */
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = { })
public @interface NotNull {

	String message() default "{javax.validation.constraints.NotNull.message}";

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

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

	/**
	 * Defines several {@link NotNull} annotations on the same element.
	 *
	 * @see javax.validation.constraints.NotNull
	 */
	@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
	@Retention(RUNTIME)
	@Documented
	@interface List {

		NotNull[] value();
	}
}

自己写注解

第一步

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {IsMobileValidator.class })
public @interface  IsMobile {
	
	boolean required() default true;
	
	String message() default "手机号码格式错误";

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

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

第二步

public class IsMobileValidator implements ConstraintValidator<IsMobile, String> {

	private boolean required = false;
	
	public void initialize(IsMobile constraintAnnotation) {
		required = constraintAnnotation.required();
	}

	public boolean isValid(String value, ConstraintValidatorContext context) {
		if(required) {
			return ValidatorUtil.isMobile(value);
		}else {
			if(StringUtils.isEmpty(value)) {
				return true;
			}else {
				return ValidatorUtil.isMobile(value);
			}
		}
	}

}

public class ValidatorUtil {
	
	private static final Pattern mobile_pattern = Pattern.compile("1\\d{10}");
	
	public static boolean isMobile(String src) {
		if(StringUtils.isEmpty(src)) {
			return false;
		}
		Matcher m = mobile_pattern.matcher(src);
		return m.matches();
	}