Properties files allow configuration values to be externalized and reused throughout a Mule application. Property placeholders can be used to reference values from properties files, enabling environment-specific configurations. Values for placeholders can come from global properties, property files, environment variables, or runtime arguments, with earlier sources taking priority.

1. USING PROPERTIES
IN MULE

2. PROPERTIES
• A properties file is a simple collection of key-value pairs that can be
parsed by the java.util.Properties class. They are often used to store
configuration or localization data. In mule properties file can be
configured using property placeholders and system properties.
Property Placeholders:
• Property placeholders allow you to upload the parameters from a
properties file. This enables you, for example, to have different property
files for different environments (Dev, QA, and Prod).

3. • It also allows you to reuse the same value in different parts of your
configuration.
• A very simple example shows how to use the property placeholders.
• The values for these placeholders can be made available in a variety of
ways, as described in the sections below.

4. Global Properties:
You can use the <global-property> element to set a placeholder value
from within your Mule configuration, such as from within another Mule
configuration file that are configured as below:

6. Property Files:
To load the properties from a file, you can use the standard spring
element <context: property-placeholder>.

7. • Where the contents of the test.properties is:
• To load multiple properties files, separate them with commas:

8. Example:
• The example above tries to display the property name which is a common
property from various sources the observation is as below:

9. Observation:
• The property in the mule-app.properties is prioritized the most, Global
variables is prioritized the next most and next is the run time arguments
followed by Environment Variables and then follows the property files in
alphabetical order.