@Valid 注释在 Spring 中表示什么? [英] What does the @Valid annotation indicate in Spring?

问题描述

在以下示例中，ScriptFile 参数使用 @Valid 注释标记.

In the following example, the ScriptFile parameter is marked with an @Valid annotation.

@Valid 注释有什么作用?

@RequestMapping(value = "/scriptfile", method = RequestMethod.POST)    
public String create(@Valid ScriptFile scriptFile, BindingResult result, ModelMap modelMap) {    
    if (scriptFile == null) throw new IllegalArgumentException("A scriptFile is required");        
    if (result.hasErrors()) {        
        modelMap.addAttribute("scriptFile", scriptFile);            
        modelMap.addAttribute("showcases", ShowCase.findAllShowCases());            
        return "scriptfile/create";            
    }        
    scriptFile.persist();        
    return "redirect:/scriptfile/" + scriptFile.getId();        
}    

推荐答案

用于验证目的.

验证 通常验证一个绑定用户输入后的模型.Spring 3 提供支持使用 JSR-303 进行声明性验证.此支持已自动启用如果 JSR-303 提供程序，例如休眠验证器，存在于你的类路径.启用后，您可以简单地触发验证注释控制器方法带有@Valid 注释的参数:绑定传入 POST 后参数，AppointmentForm 将得到验证；在这种情况下，要验证日期字段值不为空并且将来发生.

Validation It is common to validate a model after binding user input to it. Spring 3 provides support for declarative validation with JSR-303. This support is enabled automatically if a JSR-303 provider, such as Hibernate Validator, is present on your classpath. When enabled, you can trigger validation simply by annotating a Controller method parameter with the @Valid annotation: After binding incoming POST parameters, the AppointmentForm will be validated; in this case, to verify the date field value is not null and occurs in the future.

在这里查看更多信息:
http://blog.springsource.com/2009/11/17/spring-3-type-conversion-and-validation/

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