A typical problem in migration efforts occurs when the Java Native Interface (JNI) is used to implement some aspects of the applications. In many cases, re-implementation of the native code is feasible, and it may even be possible to find a better solution using mainframe resources such as data sets that offer efficient record-oriented data access natively. We discuss how to use the Java Record I/O (JRIO) library, which is a zSeries-unique I/O library, to access mainframe file systems in Chapter 3, "Access to MVS data sets" on page 31. 1.3.5 Availability of skill set for the future The argument of disappearing COBOL applications has been proven wrong, and many businesses still heavily rely on COBOL applications today. However, the trend of transitioning away from such development tools on the mainframe continues inevitably. There are several reasons for this trend: The Java programming language has been one of the most popular programming languages over the last several years. Therefore, it is easier to find developers with Java development skills than to find COBOL developers. A wide range of libraries and APIs are available for the Java programming language. These libraries and APIs facilitate efficient development of prototypes and new applications. Since requirements and environments of businesses change rapidly, and new standards and protocols are introduced frequently, the availability of libraries and APIs offers significant advantages.