我可以在Spring bean定义中使用相对路径吗？

Question

Is there a way to use relative path, say relative to class path or /META-INF in Spring bean definition file ? This is a bit different from using ServletContext to obtain such info.

For example: I am trying to define a filename for a embedded database H2.

<bean id="myDataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="org.h2.Driver"
    p:url="jdbc:h2:~/mydb;AUTO_SERVER=TRUE"
    p:username=""
    p:password="" />

~/mydb is not so desired as it depends on how and where you deploy the application, the home directory may not be there ... how can I make it to write to, for example, /WEB-INF/dbstore/ ?

BTW - I tried "classpath:" as suggested, it doesn't seem to work in this case.

Answer 1

The following resource prefixes are always valid:

Table 4.1. Resource strings

Prefix       Example                            Explanation
---------------------------------------------------------------------------
classpath: | classpath:com/myapp/config.xml  |  Loaded from the classpath.
file:      | file:/data/config.xml           |  Loaded as a URL, from the
           |                                 |  filesystem. [1]
http:      | http://myserver/logo.png        |  Loaded as a URL.
(none)     | /data/config.xml                |  Depends on the underlying
           |                                 |  ApplicationContext.

[1] But see also Section 4.7.3, “FileSystemResource caveats” .

Source: Spring Reference > The ResourceLoader

But I don't really see how relative paths fit in there. Perhaps you should elaborate your requirements.

---

Thanks for the additional info. You're right, it can't work in this context

<bean id="myDataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="org.h2.Driver"
    p:url="jdbc:h2:~/mydb;AUTO_SERVER=TRUE"
    p:username=""
    p:password="" />

Spring never analyzes that JDBC URL, it just passes it to the bean. What I'd suggest is to use the PropertyPlaceHolderConfigurer mechanism :

<bean id="myDataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="org.h2.Driver"
    p:url="jdbc:h2:${dbpath};AUTO_SERVER=TRUE"
    p:username=""
    p:password="" />

<!-- example config -->
<context:property-placeholder location="classpath:com/foo/jdbc.properties"
                              systemPropertiesMode="override"  />

Now you can either configure the path in a properties file on the classpath or per system property. Actually, you probably want to do something like this (make the entire URL configurable, not just the DB schema name):

p:url="${dbpath}"