Spring 自动装配列表

发布于 2024-11-14 07:19:35 字数 198 浏览 4 评论 0原文

是否可以将 @Autowired 与列表一起使用？

就像我有带有 mimetypes 的属性文件，在我的类文件中我有这样的东西

@Autowired
private List<String> mimeTypes = new ArrayList<String>();

原文

Is it possible to use @Autowired with a list?

Like I have properties file with mimetypes and in my class file I have something like this

@Autowired
private List<String> mimeTypes = new ArrayList<String>();

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

内心激荡 2024-11-21 07:19:35

Spring 4 及更早版本支持自动收集给定类型的所有 bean 并将它们注入到集合或数组中的功能。

这是一个示例：

@Component
public class Car implements Vehicle {
}

@Component
public class Bus implements Vehicle {
}

@Component
public class User {
   @Autowired
   List<Vehicle> vehicles; // contains both car and bus
}

参考：Spring 4 订购 Autowired 集合

Spring 4 and older support the ability to automatically collect all beans of a given type and inject them into a collection or array.

Here is an example:

@Component
public class Car implements Vehicle {
}

@Component
public class Bus implements Vehicle {
}

@Component
public class User {
   @Autowired
   List<Vehicle> vehicles; // contains both car and bus
}

Ref: Spring 4 Ordering Autowired Collections

回复收藏 0 原文

拔了角的鹿 2024-11-21 07:19:35

不鼓励使用 @Qualifier("..")，而是尝试使用 autowire-by-name

private @Resource(name="..") List<Strings> mimeTypes;

另请参阅如何自动装配factorybean。

@Qualifier("..") is discouraged, instead try to autowire-by-name using

private @Resource(name="..") List<Strings> mimeTypes;

See also How to autowire factorybean.

回复收藏 0 原文

南风起 2024-11-21 07:19:35

您甚至可以在 spring .xml 中创建一个 java.util.List 并通过 @Qualifier 将其注入到您的应用程序中。来自 springsource http://static.springsource.org/spring /docs/current/reference/xsd-config.html ：

 <!-- creates a java.util.List instance with the supplied values -->
 <util:list id="emails">
   <value>[email protected]</value>
   <value>[email protected]</value>
   <value>[email protected]</value>
   <value>[email protected]</value>
 </util:list>

所以这会将您的接线更改为：

 @Autowired
 @Qualifier("emails")
 private List<String> mimeTypes = new ArrayList<String>();

我建议采用这种方法，因为您无论如何都会注入字符串列表。

干杯！

编辑

如果您想注入属性，请查看此如何将属性值注入到使用注释配置的 Spring Bean 中？

You can even create a java.util.List within your spring .xml and inject this via @Qualifier into your application. From the springsource http://static.springsource.org/spring/docs/current/reference/xsd-config.html :

 <!-- creates a java.util.List instance with the supplied values -->
 <util:list id="emails">
   <value>[email protected]</value>
   <value>[email protected]</value>
   <value>[email protected]</value>
   <value>[email protected]</value>
 </util:list>

So this would change your wiring to:

 @Autowired
 @Qualifier("emails")
 private List<String> mimeTypes = new ArrayList<String>();

I would suggest this approach since you're injecting a list of strings anyways.

cheers!

EDIT

If you want to inject properties, have a look at this How can I inject a property value into a Spring Bean which was configured using annotations?

回复收藏 0 原文

旧城烟雨 2024-11-21 07:19:35

我认为你至少需要一个限定符。而所谓的“新”似乎与使用Spring的理念相悖。你对 Spring 的角色感到困惑。如果你调用“new”，那么该对象就不受Spring的控制。

回复收藏 0 原文

压抑⊿情绪 2024-11-21 07:19:35

如果自动装配的 bean 在同一个 (@Configuration) 类中声明，并且您需要它来声明另一个 bean，则可以执行以下操作：

@Bean
public BeanWithMimeTypes beanWithMimeTypes() {
    return new BeanWithMimeTypes(mimeTypes());
}

@Bean
public List<String> mimeTypes() {
    return Arrays.<String>asList("text/html", "application/json);
}

即使您覆盖 mimeTypes 另一个配置中的 bean。不需要显式的 @Qualifier 或 @Resource 注释。

If the autowired bean is declared in the same (@Configuration) class and you need it to declare another bean, then following works:

@Bean
public BeanWithMimeTypes beanWithMimeTypes() {
    return new BeanWithMimeTypes(mimeTypes());
}

@Bean
public List<String> mimeTypes() {
    return Arrays.<String>asList("text/html", "application/json);
}

Naturally it behaves correctly even if you override the mimeTypes bean in another config. No need for explicit @Qualifier or @Resource annotations.

回复收藏 0 原文