spring mvc处理方法入参注解个数问题

[zdd2389]

spring mvc处理方法入参最多是不是只能有一个？在看书的时候看到一行代码感觉跟这个说法不一样，这是为什么？

[技术控_]

啥意思?肯定能入参多个参数撒.

[zdd2389]

引用 1 楼 QQ233040940 的回复:

啥意思?肯定能入参多个参数撒.

是说每个入参的注解个数

[如果一切再重来]

注解也可以有多个

[解开者]

不是一个功能，ModelAttribute是参数绑定，Valid是调用JSR303参数校验

[技术控_]

注解个数并没有限制啊.

[小白晒太阳]

@Target({ElementType.PARAMETER, ElementType.METHOD}) 
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ModelAttribute {

	/**
	 * The name of the model attribute to bind to.
	 * <p>The default model attribute name is inferred from the declared
	 * attribute type (i.e. the method parameter type or method return type),
	 * based on the non-qualified class name:
	 * e.g. "orderAddress" for class "mypackage.OrderAddress",
	 * or "orderAddressList" for "List<mypackage.OrderAddress>".
	 */
	String value() default "";

}


@Target({ElementType.TYPE, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Validated {

	/**
	 * Specify one or more validation groups to apply to the validation step
	 * kicked off by this annotation.
	 * <p>JSR-303 defines validation groups as custom annotations which an application declares
	 * for the sole purpose of using them as type-safe group arguments, as implemented in
	 * {@link org.springframework.validation.beanvalidation.SpringValidatorAdapter}.
	 * <p>Other {@link org.springframework.validation.SmartValidator} implementations may
	 * support class arguments in other ways as well.
	 */
	Class<?>[] value() default {};

}

取决于注解的定义吧，我没找到@Valid，找到了@Validated 你看2个注解 @Target都标注可以用于声明在PARAMETER（参数上） 应该没问题

[Linda L]

你的例子里边把参数封装到一个实体里一起接收啦