Some input files use or override a deprecated API

according to comments in older SO question, "-Xlint in NetBeans is set under project properties, run or compile options" - see details here: Compiling issue in NetBeans

There is also a thread at Netbeans forums. They say,

Go to the Compiling section of the Project Properties. These is a check box labeled "Report use of deprecated API". Checking that will turn on -Xlint.