IBM^® i5/OS PASE native methods for Java

The iSeries™ Java™ virtual machine (JVM) supports the use of native methods running in the i5/OS™ PASE environment. Prior to V5R2, the native iSeries JVM used only ILE native methods.

Support for i5/OS PASE native methods includes:

• Full use of the native iSeries Java Native Interface (JNI) from i5/OS PASE native methods
• The ability to call i5/OS PASE native methods from the native iSeries JVM

This new support enables you to easily port your Java applications that run in AIX^® to your iSeries server. You can copy the class files and AIX native method libraries to the integrated file system on the iSeries and run them from any of the control language (CL), Qshell or i5/OS PASE terminal session command prompts.

• Java i5/OS PASE environment variables
  The Java virtual machine (JVM) uses the following variables to start i5/OS PASE environments. You need to set the QIBM_JAVA_PASE_STARTUP variable in order to run the IBM^® i5/OS PASE native method for Java example.
• Java i5/OS PASE error codes
  To help you troubleshoot i5/OS PASE native methods, this topic describes error conditions that are indicated by i5/OS job log messages and Java runtime exceptions. The following lists describe errors that you may encounter at start up or at run time when using i5/OS PASE native methods for Java.
• Managing native method libraries
  To use native method libraries, especially when you want to manage multiple versions of a native method library on your iSeries server, you need to understand both the Java library naming conventions and the library search algorithm.
• Example: IBM i5/OS PASE native method for Java
  The IBM^® i5/OS PASE native method for Java example calls an instance of a native C method that then uses Java Native Interface (JNI) to call back into Java code. Rather than accessing the string directly from Java code, the example calls a native method that then calls back into Java through JNI to get the string value.