Spring is the leading IOC-container and with the PropertiesPlaceHolder and the PropertyOverrideConfigurer it is easy to use Properties within the Spring Context. PrefixedProperties comes with it's own PrefixedPropertiesPlaceHolder and PrefixedPropertyOverrideConfigurer. They extends the PropertiesPlaceHolder and PropertyOverrideConfigurer from Spring and gives the possibility to have different Properties for different environments within Spring.
You can use setDefaultPrefix to specify the environment. There is no need to specify any PrefixConfigs. Or you can specify a System-Property which should be used for the environment.
application.properties:
test.key1=testvalue1 test.key2=testvalue2 liv.key1=myLiveValue1 liv.key2=myLiveValue2
applicationContext.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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">
<bean class="net.sf.prefixedproperties.spring.PrefixedPropertiesPlaceholderConfigurer">
<property name="defaultPrefixSystemPropertyKey" value="environment"/>
<property name="location" value="classpath:application.properties"/>
</bean>
<bean id="bean1" class="net.sf.prefixedproperties.Bean">
<property name="property1" value="${key1}"</property>
<property name="property2" value="${key2}"</property>
</bean>
</beans>
With java -cp ... -Denvironment=test ... the environment will be set.
If you use a different way to set your environment, you can implement your own EnvironmentFactory that is used to get an prefix from it which will be used as defaultPrefixConfig.
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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">
<bean class="net.sf.prefixedproperties.spring.PrefixedPropertiesPlaceholderConfigurer">
<property name="environmentFactory" ref="environmentFactory"/>
<property name="location" value="classpath:application.properties"/>
</bean>
<bean id="environmentFactory" class="com.company.MyEnvironmentFactory">
...
</bean>
<bean id="bean1" class="net.sf.prefixedproperties.Bean">
<property name="property1" value="${key1}"</property>
<property name="property2" value="${key2}"</property>
</bean>
</beans>
Or just set your environment directly:
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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">
<bean class="net.sf.prefixedproperties.spring.PrefixedPropertiesPlaceholderConfigurer">
<property name="defaultPrefix" value"myEnvironement.myHost"/>
<property name="location" value="classpath:application.properties"/>
</bean>
<bean id="bean1" class="net.sf.prefixedproperties.Bean">
<property name="property1" value="${key1}"</property>
<property name="property2" value="${key2}"</property>
</bean>
</beans>
A special function of the PrefixedPropertiesPlaceholderConfigurer is the possibility to process the replacements of other properties within the spring context. For that you can set the property processProperties to true. This is an powerful function in case you need to load your own subset of properties and you don't want to mix them up with other property configurations. For example Log4j.
applicationContext.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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">
<bean class="net.sf.prefixedproperties.spring.PrefixedPropertiesPlaceholderConfigurer">
<property name="defaultPrefix" value"myEnvironement.myHost"/>
<property name="location" value="classpath:application.properties"/>
<property name="processOtherProperties" value="true"/>
</bean>
<bean id="log4j" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="location" value="classpath:log4j_replacements.properties"/>
</bean>
</beans>
application.properties:
dev.LOGLEVEL=debug test.LOGLEVEL=debug qa.LOGLEVEL=info prod.LOGLEVEL=warn ROOTLOGGER=CONSOLE, CONSOLE2 prod.ROOTLOGGER=CONSOLE
log4j_replacements.properties:
log4j.rootLogger=${LOGLEVEL}, ${ROOTLOGGER}
# CONSOLE is set to be a ConsoleAppender.
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
# CONSOLE uses PatternLayout.
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
# CONSOLE is set to be a ConsoleAppender.
log4j.appender.CONSOLE2=org.apache.log4j.ConsoleAppender
# CONSOLE uses PatternLayout.
log4j.appender.CONSOLE2.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE2.layout.ConversionPattern=%-4r %-5p %c %x - %m%n