Beside installing 3rd party JARs in maven using mvn install it is posible to use external jars directly in pom.xml in depenency declaration just include systemPath
<dependency>
<groupId>ro.springsoft</groupId>
<artifactId>libar</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${basedir}\ext-libs\libar.jar</systemPath>
</dependency>