Injecting external properties into Java EE 6/7 applications

A set of 2 annotations that allow to simply inject properties from properties files.

Features:

• Inject a property by simply annotating a String attribute
• Annotate a class to specify the properties files to load
• Alternatively, properties files can be listed in a configuration file
• Supports field injection and method injection
• Uses CDI to perform the injection

Technologies

• Java EE 6 with CDI 1.0 enabled

How to build

To build the jar

mvn clean compile package

To run integration tests

mvn verify

To build the jar and run integration tests

mvn clean install

How to use annotations

• Build the jar and drop it with dependencies
• Annotate the class where the injection will be performed with the @PropertiesFiles annotation, this annotation will list all the properties files that will be loaded

@PropertiesFiles({"file1.properties", "file2.properties"})
public MyClass {
    ....
}

• alternatively you can list the files in a configuration file named inject.property.xml, this file must be available in the classpath

<propertiesfiles>
	<file>file1.properties</file>
	<file>file2.properties</file>
	....
	<file>fileN.properties</file>
</propertiesfiles>

• Annotate a String attribute (the type string is mandatory as of current version) that will receive the value of the property with the annotations @Inject and @Property("${property.key}") where ${property.key} is the key of the property in the properties file

@PropertiesFiles({"emails.properties"})
public MyClass {

    @Inject
    @Property("admin.email")
    private String adminEmail;
    ....
}

• Method injection can also be used

@PropertiesFiles({"emails.properties"})
public MyClass {

    private String adminEmail;

    @Inject
    public void setAdminEmail(@Property("admin.email") String adminEmail) {
        this.adminEmail = adminEmail;
    }
    ....
}

How it works

• The files listed in the annotation @PropertiesFiles are loaded and used for the injection, the files listed in the configuration file inject.property.xml are ignored
• If @PropertiesFiles is not present then inject.property.xml is used