Maven: How can I use a separate file specifying developer-specific config?

Database URL, username, password vary in our developer team. Now I want to use this way and set up the profile in pom.xml:

<profiles>
  <profile>
    <id>local</id>

    <properties>
      <db.url>jdbc:mysql://127.0.0.1:3306/xx?sendStringParametersAsUnicode=false</db.url>
      <db.mysql.username>xx</db.mysql.username>
      <db.mysql.password>xx</db.mysql.password>
      <serverBaseUrl>http://127.0.0.1:8080</serverBaseUrl>
    </properties>

    <activation>
      <activeByDefault>true</activeByDefault>
    </activation>

  </profile>

  <profile>
    <id>test</id>

    <properties>
      <db.url>jdbc:mysql://xx/xx?sendStringParametersAsUnicode=false</db.url>
      <db.mysql.username>xx</db.mysql.username>
      <db.mysql.password>xx</db.mysql.password>
      <serverBaseUrl>http://xx:8133</serverBaseUrl>
    </properties>

    <activation>
      <activeByDefault>false</activeByDefault>
    </activation>

  </profile>
</profiles>

I want properties like db.mysql.username be set in a separate file named developer-specific-config.properties, and create a file name developer-specific-config.properties.example to tell other developers how to use. Also, I'd like to add developer-specific-config.properties to gitignore so that it won't be traced.

How to finish it?