We had a filters configuration, defined for the assembly plugin in the first example with WSO2 Identity Server. This instructs the assembly plugin to apply the filter criteria defined in the provided filter or the set of filters for the files being copied to the final archive file. If you want to apply the filters to a given file, then you should set the value of the filtered element to true. The following configuration shows how to define a filter criteria with a property file:

<filters>
  <filter>${basedir}/src/assembly/filter.properties</filter>
</filters>

Let's have a look at the ${basedir}/src/assembly/filter.properties file. This file defines a set of name/value pairs. The name is a special placeholder, which should be enclosed between ${ and } in the file to be filtered, and during the filtering process, it will be replaced by the value. Say for example, the value ${product.name} in the original file will be replaced with WSO2 Identity Server after the filtering process:

product.name=WSO2 Identity Server
product.key=IS
product.version=5.0.0 
hotdeployment=true
hotupdate=true
default.server.role=IdentityServer