Migrating API and specifications

Migrating application programming interfaces (APIs) and specifications involves moving to the current Java™ component level as well as to other technologies that WebSphere® Application Server Version 8.5 supports. If your existing applications currently support different specification levels than are supported by this version of the product, it is likely that you must update at least some aspects of the applications to comply with the new specifications.

Supported configurations:

This topic is about configuration migration, such as migrating deployment managers and federated nodes in a network deployment environment. The Application Migration Toolkit for WebSphere Application Server provides support for migrating applications from previous versions of WebSphere Application Server to the latest product version. For information about migrating applications, read more about the Migration Toolkit.

In many cases, IBM® provides additional features and customization options that extend the specification level even further. If your existing applications use IBM extensions from earlier product versions, it might be necessary for you to perform mandatory or optional migration to use the same kinds of extensions in Version 8.5.

WebSphere Application Server Version 8.5 supports Java SE Development Kit (JDK) 7.

Notes on the use of Java SE Development Kit:
  • [8.5.5.14 or later]Starting in version 8.5.5.14, Java SE 8 is the default Java. When updating to 8.5.5.14, any existing profile that uses Java SDK 6 is replaced by Java SDK 8. You can continue to use Java SDK Java Technology Edition Version 7.0 and Version 7.1, but no service can be provided after the end of support in July 2022, which could expose your environment to security risks.
  • Starting in version 8.5.5.11, you must install either Java SE 6 or Java SE 8 as the version of Java SE contained in the /java and /java64 directories in WebSphere Application Server and used by default during server and node configuration. Java 8 is the recommended Java SDK because it provides the latest features and security updates. You can continue to use Java SE 6, but no service can be provided after the end of support in April 2018, which could expose your environment to security risks. To take advantage of the latest features and security updates, migrate to a higher Java SE version.
  • WebSphere Application Server began supporting Java SE Development Kit (JDK) 6 in Version 8.0.

    For more information about JDK 6, see JSR 270: Java SE 6 Release Contents and Java SE 6.

  • In general, existing Version 6.1 application binaries that were developed using JDK 1.4 and 5 are highly compatible and typically do not require modifications to run. However, recompilation of the JDK 1.4 or 5 applications at the JDK 6 level might necessitate modifications of the source code to conform to incompatible changes that are present in JDK 6. As part of your migration planning, you should review the JDK compatibility restrictions that are documented at Java SE 6 Release Notes: Compatibility.
  • A mixed cell containing Version 6.1 and Version 7.0 nodes requires that all application binaries deployed on Version 6.1 remain at the lowest JDK level associated with the Version 6.1 nodes. Although you can successfully migrate Version 6.1 applications to Version 8.5, this is only meant to be a temporary state as you transition to Version 8.5. After you begin migration to Version 8.5, plan to complete the migration of the entire cell, update your tooling to Version 8.5, and update your applications to conform to JDK 6 requirements. Complete this action before any further application changes. After you have completely migrated your cell to Version 8.5, upgrade your application binaries to the JDK 6 level the next time that you make application modifications that require recompiling. This action might require source code changes to your application to conform to the JDK 6 API changes as documented.
Deprecated features: The Java Virtual Machine Debug Interface (JVMDI) and the Java Virtual Machine Profiler Interface (JVMPI) were deprecated in JDK 5 and removed in JDK 6. Read Java SE 6 Release Deprecated API for more information.

See Specifications and API documentation for a summary of the specifications and API documentation supported in current and prior product releases.

For more information on the items deprecated in WebSphere Application Server Version 8.5, see Deprecated, stabilized, and removed features.