Front cover Java Stand-alone Applications on z/OS Volume 1 Setting up an environment for managing Java programs on z/OS Building, deploying, running, and debugging applications Analyzing application performance and exploiting zAAP Alex Louwe Kooijmans Paul Anderson Kenichi Yoshimura Linfeng Yu ibm.com/redbooks International Technical Support Organization Java Stand-alone Applications on z/OS Volume 1 May 2006 SG24-7177-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (May 2006) This edition applies to IBM SDK for z/OS, Java 2 Technology Edition, productnumber 5655-I56. © Copyright International Business Machines Corporation 2006. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii Preface . ix The team that wrote this redbook. x Become a published author . xi Comments welcome. xi Chapter 1. Scenarios for running Java stand-alone applications on z/OS 1 1.1 Definition of Java stand-alone applications . 2 1.1.1 Definition of batch applications . 2 1.2 Legacy system modernization. 3 1.3 Reasons to use Java for stand-alone applications . 5 1.3.1 Functionality . 6 1.3.2 XML processing . 6 1.3.3 Reusing J2EE online program logic . 7 1.3.4 Migrating Java applications for QoS and server consolidation . 7 1.3.5 Availability of skill set for the future . 8 1.3.6 zAAP processor . 8 1.4 Topologies of Java stand-alone applications . 9 Chapter 2. Job management . 11 2.1 The first Java program on z/OS . 12 2.2 Running a Java program as a batch job . 12 2.2.1 Overview of Job Control Language. 13 2.2.2 Writing JCL for a Java batch job . 18 2.2.3 Limitations of BPXBATCH. 20 2.2.4 BPXBATSL . 21 2.2.5 Comparison of JCLBATCH and JCLBATSL . 22 2.3 Developing multi-step jobs . 22 2.3.1 Specifying multiple steps in a JCL script. 23 2.3.2 Conditions on a step . 25 2.3.3 Conditional step execution using IF-ELSE . 26 2.4 Design considerations for multi-step jobs . 27 2.4.1 What skill sets are available in the development team? . 27 2.4.2 How much integration with legacy applications is necessary? . 27 2.4.3 How much control is required between steps? . 27 2.4.4 Return code from BPXBATCH and BPXBATSL . 28 © Copyright IBM Corp. 2006. All rights reserved. iii Chapter 3. Access to MVS data sets . 31 3.1 The JRIO library . 32 3.1.1 JRIO classes and interfaces . 32 3.1.2 JRIO usage examples. 35 3.2 Working with VSAM data sets . 41 3.2.1 VSAM overview. 41 3.2.2 Accessing records in a VSAM data set using the JRIO library . 42 3.3 Working with COBOL packed decimal numbers . 46 3.3.1 Converting from COBOL packed decimals to Java integers. 48 3.3.2 Converting from Java integers to COBOL packed decimals. 49 3.4 JRecord bean generator and supporting APIs . 50 3.4.1 JRecord utility APIs . 50 3.4.2 Generating a Java bean for a record . 50 3.4.3 JRecord runtime library and plug-in installation . 60 Chapter 4. Tools and techniques . 61 4.1 Introduction . 62 4.2 Application build and deployment . 62 4.2.1 Ant support in Eclipse . 62 4.2.2 Set up Ant ftp support in Eclipse . 65 4.2.3 Build and deployment Ant script . 66 4.2.4 Use the ANT buildfile . 70 4.2.5 Further discussion. 71 4.3 Debugging . 72 4.3.1 Remote debugging . 72 4.3.2 Preparing the Java program . 73 4.3.3 Creating a shell script and JCL . 75 4.3.4 Deploying and starting a Java application. 78 4.3.5 Work with the debugger in the Eclipse workbench . 82 4.3.6 Local debugging . 89 4.3.7 Rational Application Developer considerations. 90 Chapter 5. Measuring performance and application profiling . 91 5.1 Performance analysis . 92 5.1.1 Tooling overview . 92 5.1.2 Establishing a goal . 93 5.2 Overview of analysis strategies. 94 5.2.1 Statistical. 94 5.2.2 Fractional . 94 5.2.3 Elimination. 95 5.2.4 Accurate . 95 5.3 Statistical analysis . 95 5.4 Fractional analysis. 96 iv Java Stand-alone Applications on z/OS Volume 1 5.4.1 TIMEUSED . 103 5.5 Elimination analysis. 111 5.6 Accurate analysis . 112 5.6.1 Installing TPTP . 112 5.6.2 Profiling an application on z/OS . 126 5.6.3 Fractional analysis with TPTP. 155 5.7 Code listings . 165 Chapter 6. Exploiting zAAP . 173 6.1 zAAP prerequisites . 174 6.2 Overview of zAAP and runtime options. 174 6.3 Exploring zAAP utilization potentials . 175 6.3.1 zAAP utilization estimate and projection tool . 175 6.3.2 Experimental results of zAAP utilization estimates . 178 6.3.3 Hardware and software configuration . 181 Chapter 7. Problem determination. 183 7.1 Introduction . 184 7.2 Checking the z/OS environment . 184 7.2.1 Maintenance . ..