A property resource configurer that resolves placeholders in bean property values of
context definitions. It pulls values from a properties file into bean definitions.
The default placeholder syntax follows the Ant / Log4J / JSP EL style:
PropertyPlaceholderConfigurer checks simple property values, lists, maps,
props, and bean names in bean references. Furthermore, placeholder values can
also cross-reference other placeholders, like:
rootPath=myrootdir
subPath=${rootPath}/subdir
In contrast to PropertyOverrideConfigurer, this configurer allows to fill in
explicit placeholders in context definitions. Therefore, the original definition
cannot specify any default values for such bean properties, and the placeholder
properties file is supposed to contain an entry for each defined placeholder.
If a configurer cannot resolve a placeholder, a BeanDefinitionStoreException
will be thrown. If you want to check against multiple properties files, specify
multiple resources via the "locations" setting. You can also define multiple
PropertyPlaceholderConfigurers, each with its own placeholder syntax.
Default property values can be defined via "properties", to make overriding
definitions in properties files optional. A configurer will also check against
system properties (e.g. "user.dir") if it cannot resolve a placeholder with any
of the specified properties. This can be customized via "systemPropertiesMode".
Note that the context definition is aware of being incomplete;
this is immediately obvious when looking at the XML definition file.
Property values can be converted after reading them in, through overriding
the convertPropertyValue method. For example, encrypted values
can be detected and decrypted accordingly before processing them.
The default placeholder syntax follows the Ant / Log4J / JSP EL style:
${...}Example XML context definition:
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"><value>${driver}</value></property> <property name="url"><value>jdbc:${dbname}</value></property> </bean>Example properties file: PropertyPlaceholderConfigurer checks simple property values, lists, maps, props, and bean names in bean references. Furthermore, placeholder values can also cross-reference other placeholders, like:rootPath=myrootdir subPath=${rootPath}/subdirIn contrast to PropertyOverrideConfigurer, this configurer allows to fill in explicit placeholders in context definitions. Therefore, the original definition cannot specify any default values for such bean properties, and the placeholder properties file is supposed to contain an entry for each defined placeholder.If a configurer cannot resolve a placeholder, a BeanDefinitionStoreException will be thrown. If you want to check against multiple properties files, specify multiple resources via the "locations" setting. You can also define multiple PropertyPlaceholderConfigurers, each with its own placeholder syntax.
Default property values can be defined via "properties", to make overriding definitions in properties files optional. A configurer will also check against system properties (e.g. "user.dir") if it cannot resolve a placeholder with any of the specified properties. This can be customized via "systemPropertiesMode".
Note that the context definition is aware of being incomplete; this is immediately obvious when looking at the XML definition file.
Property values can be converted after reading them in, through overriding the
convertPropertyValuemethod. For example, encrypted values can be detected and decrypted accordingly before processing them.