Spring DI applicationContext.xml究竟是如何使用xsi:schemaLocation的？_Spring_Dependency Injection_Applicationcontext

Spring DI applicationContext.xml究竟是如何使用xsi:schemaLocation的？

spring dependency-injection

Spring DI applicationContext.xml究竟是如何使用xsi:schemaLocation的？,spring,dependency-injection,applicationcontext,Spring,Dependency Injection,Applicationcontext,注意：我提到的测试项目可以通过以下方式下载： <beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"

注意：我提到的测试项目可以通过以下方式下载：

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

git克隆

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

。。和“蚂蚁跑”一起跑

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

我“理解”XML名称空间名称只是用作不透明标识符，并不打算用作URI（）。我还“理解”XML模式位置旨在提供关于模式文档实际位置的提示，作为提示，在实践中没有使用（）。考虑到这一点，我一直在通过修改applicationContext.xml来试验一个简单的springdi应用程序（在简单的J2SE设置中使用）。以下是起始版本：

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

这似乎表明SpringDI运行时使用xsi:schemaLocation中每对中的第二个URL作为某种标识符（由于没有网络访问，所以在其逻辑中进行了硬编码）。因此，我的假设是Spring DI运行时对每个名称空间使用两种标识符：xmlns标识符来唯一标识名称空间（用作不透明字符串）和schemaLocation标识符来唯一标识该名称空间的模式版本（再次用作不透明字符串）。也就是说，schemaLocation实际上被用来（以一种扭曲的方式？因为w3c文档似乎并不打算这样做）对名称空间进行版本化。此外，在这种情况下，为什么Spring DI运行时不抱怨“p”命名空间缺少schemaLocation。我的思维模式正确吗

以下是发生的情况：

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

XMLSchema允许您为XML名称空间定义别名（简称）。从技术上讲，所有名称空间都由完整URI标识，但这将非常麻烦-因此您可以使用短别名，如
```
context
```
和
```
p
```
。还有一个默认名称空间，由
```
xmlns
```
属性表示

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

默认情况下，XML解析器假定命名空间URI也是XSD文件URL位置。通常是这样，但规范并不要求这样做。如果不提供
```
schemaLocation
```
属性，Spring中的XML解析器也是这样工作的

<beans xmlns             = "http://www.springframework.org/schema/beans"                                             
      xmlns:xsi         = "http://www.w3.org/2001/XMLSchema-instance"                                               
      xmlns:context     = "http://www.springframework.org/schema/context"                                           
      xmlns:p           = "http://www.springframework.org/schema/p"                                                 
      xsi:schemaLocation="http://www.springframework.org/schema/beans                                               
                          http://www.springframework.org/schema/beans/spring-beans-2.5.xsd                          
                          http://www.springframework.org/schema/context                                             
                         http://www.springframework.org/schema/context/spring-context-2.5.xsd">                    

<context:component-scan base-package="atm"/>                                                                       
<context:property-placeholder location="classpath:META-INF/spring/atm.properties"/>                                

<bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

```
schemaLocation
```
用于从命名空间URI映射到XSD文件物理位置（URL）。当模式名称空间不指向有效的XSD URL时使用它（请参阅）

<beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns:context = "http://www.springframework.org/schema/context" xmlns:p = "http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"> <context:component-scan base-package="atm"/> <context:property-placeholder location="classpath:META-INF/spring/atm.properties"/> <bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

最后但并非最不重要的一点是，Spring添加了另一层，将Internet URL转换为类路径上的本地文件。这样，您的应用程序就可以在没有Internet连接的情况下启动（或者当springframework.org网站关闭时）

<beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns:context = "http://www.springframework.org/schema/context" xmlns:p = "http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"> <context:component-scan base-package="atm"/> <context:property-placeholder location="classpath:META-INF/spring/atm.properties"/> <bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/>

如果搜索项目库，您将找到几个名为
spring.schemas
的文件。这些文件包含以下类似的行（摘自
spring context.jar中的文件，我添加了对齐）： <beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns:context = "http://www.springframework.org/schema/context" xmlns:p = "http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"> <context:component-scan base-package="atm"/> <context:property-placeholder location="classpath:META-INF/spring/atm.properties"/> <bean id="soapTransport_" class="atm.SoapATMTransport" p:retries="${transport.retries}"/> 谢谢，这是一个清晰的模型。如果可以的话，还有两个问题：[1]在我的项目库中只有一个spring.schemas文件（在spring.jar中），而且它似乎不包含您为“xsi”和“p”名称空间描述的映射（尽管我可以找到“context”和根名称空间映射），[2]映射的东西记录在哪里？@MenelaosPerdikeas：不幸的是，我不知道[1]和[2]的答案。