java Spring MVC 自定义方法参数绑定
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/6519322/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Spring MVC customized method parameter binding
提问by perdian
I'm looking for a way to customize the default Spring MVC parameter binding. Take this method as an example:
我正在寻找一种自定义默认 Spring MVC 参数绑定的方法。以这个方法为例：
@RequestMapping(value="/index.html")
public ModelAndView doIndex(@RequestParam String param) {
...
This is easy, when I have just a Stringthat I want to extract from the request. However, I want to populate a more complete object, so that my method looks like this:
这很容易，当我只有一个String我想从请求中提取的内容时。但是，我想填充一个更完整的对象，以便我的方法如下所示：
@RequestMapping(value="/index.html")
public ModelAndView doIndex(Foo bar) {
...
What I'm looking for is some way to declare a binding like this;
我正在寻找的是某种方式来声明这样的绑定；
@RequestMapping(value="/index.html")
public ModelAndView doIndex(@FooPopulator Foo bar) {
...
And have some other kind of implementor (determined by the @FooPopulatorannotation) that does this:
并有一些其他类型的实现者（由@FooPopulator注释确定）来执行此操作：
public void doBind(Foo target, ServletRequest originalRequest) {
target.setX(this.computeStuffBasedOn(originalRequest));
target.sety(y);
}
So far I've found out about the @InitBinderbinder annotaion but I'm unsure whether that's really the right choice for this scenarion.
到目前为止，我已经了解了@InitBinder活页夹注释，但我不确定这是否真的是这个场景的正确选择。
What's the best way?
最好的方法是什么？
采纳答案by perdian
just a quick thank you and the info, that I've found the "correct" solution to the problem. Spring already provides the WebArgumentResolverfor this scenario.
只是快速感谢您和信息，我已经找到了问题的“正确”解决方案。Spring 已经WebArgumentResolver为此场景提供了。
http://scottfrederick.blogspot.com/2011/03/customizing-spring-3-mvcannotation.html
http://scottfrederick.blogspot.com/2011/03/customizing-spring-3-mvcannotation.html
回答by Ralph
It is very easy. You can use Converters (that work like one way PropertyEditors but are stateless).
这很容易。您可以使用转换器（其工作方式类似于 PropertyEditor，但无状态）。
See chapter 5.5 Spring 3 Type Conversionin Spring reference.
请参阅Spring 参考中的第5.5章Spring 3 类型转换。
If such an converter is registered once, you do not need any additional information, you can simply use
如果此类转换器注册一次，则不需要任何其他信息，只需使用
@RequestMapping(value="/index.html")
public ModelAndView doIndex(@RequestParam Foo param) {
For example a simple converter that load an object by its id:
例如一个简单的转换器，它通过它的 id 加载一个对象：
@Component
@CustomConverter //custom qualifyer
public class BUdToUserConverter implements Converter<String, User> {
@Resource
private UserDao userDao;
@Override
public User convert(String source) {
Integer id = Integer.parse(source);
return this.userDao.getByBusinessId(id);
}
}
A "helper" that registers all Beans with @CustomConverter anntoation
使用@CustomConverter 注释注册所有 Bean 的“帮助程序”
public class ApplicationConversionServiceFactoryBean extends FormattingConversionServiceFactoryBean {
@Resource
@CustomConverter
private List<Converter<?, ?>> customConverter;
@Override
protected void installFormatters(final FormatterRegistry registry) {
super.installFormatters(registry);
for (Converter<?, ?> converter : customConverter) {
registry.addConverter(converter);
}
}
}
How to use it
如何使用它
UserController {
...
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
public ModelAndView show(@PathVariable("id") User user) {
return new ModelAndView("users/show", "user", user);
}
}
