Comparison between Oracle JDK, Oracle OpenJDK, and Red Hat OpenJDK.v1.0.20191009

Editor's Notes

• #4: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA). OpenJDK and Oracle JDK are implementations of the same Java SE specification. In 2017, Oracle committed to open sourcing the remaining Java SE tools with the goal of making Oracle JDK and OpenJDK interchangeable. While some minor differences still exist, OpenJDK 11 and Oracle JDK 11 are now functionally interchangeable. The builds are nearly identical except for a few features (e.g., Advanced Management Console) that are shipped separately via the Java SE Advanced commercial offering.
• #5: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA).
• #6: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA).
• #7: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA).
• #8: Resolution Following is a basic list and not specific to any java version. Serviceability: OpenJDK 8 does not contain Mission Control. Red Hat is distributing Mission Control for OpenJDK 11, and is working on supporting OpenJDK 8 with Mission Control. Font: The font library is different. This means slightly different text layout in some cases. CMS: Same for the colour management system. OpenJDK uses the same solutions as the rest of RHEL (FreeType & LCMS) while the proprietary JDK has established existing code that it has used for many years. OpenJDK use the RHEL system NSS crypto library, not the JDK's built-in one. This mostly affects elliptic curve cryptography, where OpenJDK supports all of the RHEL curves and none of the others. 2D library: OpenJDK has its own 2D library, different from the proprietary JDK. This means that its performance is different. Application Class Data Sharing is part of OpenJDK since OpenJDK 10. This feature reduces memory footprint by sharing class metadata. OpenJDK doesn't support the Resource Management API for Java. OpenJDK doesn't support the Simple Network Management Protocol API. OpenJDK has its own browser plugin and Java Web Start application (icedtea-web package). We wrote this independently of Oracle. Icedtea-web is currently supported on RHEL with OpenJDK 7 and 8 and adding Web Start support through it for Windows with OpenJDK 8 is in progress. OpenJDK doesn't support Cooperative Memory Management. This allows the user to tune the G1 garbage collector depending on a compromise between memory usage and performance. OpenJDK supports system-tap. OpenJDK is provided with full-debug clone-build (-debug- subpackages). OpenJDK comes with javadocs. Both zipped and uncompressed. OpenJDK is delivered with full sources. OpenJDK uses system tzdata and system certificates (Oracle has these bundle). OpenJDK 8 and 11 from Red Hat fully support Shenandoah, an low pausetime Garbage Collector for large heaps.
• #9: Oracle JDK contained some additional modules that were not part of corresponding OpenJDK releases: Resource Management API (jdk.management.resource) Simple Network Management Protocol API (jdk.snmp) Cooperative Memory Management (jdk.management.cmm) Flight Recorder (jdk.jfr, jdk.management.jfr) The Java Packager Tool (jdk.packager.services) JavaFX (javafx.media, javafx.web, javafx.base, javafx.controls, javafx.fxml, javafx.graphics) The output of the java --version and java –fullversion commands will distinguish Oracle JDK builds from OpenJDK builds java --version with an Oracle JDK 11 build results in: java 11 2018-09-25 Java(TM) SE Runtime Environment 18.9 (build 11+28) Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11+28, mixed mode) java --version with an Oracle Open JDK 11 build results in: openjdk version "11" 2018-09-25 OpenJDK Runtime Environment 18.9 (build 11+28) OpenJDK 64-Bit Server VM 18.9 (build 11+28, mixed mode) The Oracle JDK: It has always required third party cryptographic providers to be signed by a known certificate. It will continue to require a valid signature. The OpenJDK: The cryptography framework in OpenJDK has an open cryptographic interface, meaning it does notrestrict which providers can be used. It builds will continue to allow the use of either a valid signature or unsigned third party crypto provider. • Oracle JDK 11 will continue to include installers, branding and JRE packaging for an experience consistent with legacy desktop uses. Oracle OpenJDK builds are currently available as zip and tar.gz files, while alternative distribution formats are being considered.
• #10: Oracle JDK contained some additional modules that were not part of corresponding OpenJDK releases: Resource Management API (jdk.management.resource) Simple Network Management Protocol API (jdk.snmp) Cooperative Memory Management (jdk.management.cmm) Flight Recorder (jdk.jfr, jdk.management.jfr) The Java Packager Tool (jdk.packager.services) JavaFX (javafx.media, javafx.web, javafx.base, javafx.controls, javafx.fxml, javafx.graphics) The output of the java --version and java –fullversion commands will distinguish Oracle JDK builds from OpenJDK builds java --version with an Oracle JDK 11 build results in: java 11 2018-09-25 Java(TM) SE Runtime Environment 18.9 (build 11+28) Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11+28, mixed mode) java --version with an Oracle Open JDK 11 build results in: openjdk version "11" 2018-09-25 OpenJDK Runtime Environment 18.9 (build 11+28) OpenJDK 64-Bit Server VM 18.9 (build 11+28, mixed mode) The Oracle JDK: It has always required third party cryptographic providers to be signed by a known certificate. It will continue to require a valid signature. The OpenJDK: The cryptography framework in OpenJDK has an open cryptographic interface, meaning it does notrestrict which providers can be used. It builds will continue to allow the use of either a valid signature or unsigned third party crypto provider. • Oracle JDK 11 will continue to include installers, branding and JRE packaging for an experience consistent with legacy desktop uses. Oracle OpenJDK builds are currently available as zip and tar.gz files, while alternative distribution formats are being considered.
• #11: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA).
• #12: Java SE Technology Compatibility Kit (TCK) under the terms of the OpenJDK Community TCK License Agreement (OCTLA).
• #13: Resolution Following is a basic list and not specific to any java version. Serviceability: OpenJDK 8 does not contain Mission Control. Red Hat is distributing Mission Control for OpenJDK 11, and is working on supporting OpenJDK 8 with Mission Control. Font: The font library is different. This means slightly different text layout in some cases. CMS: Same for the colour management system. OpenJDK uses the same solutions as the rest of RHEL (FreeType & LCMS) while the proprietary JDK has established existing code that it has used for many years. OpenJDK use the RHEL system NSS crypto library, not the JDK's built-in one. This mostly affects elliptic curve cryptography, where OpenJDK supports all of the RHEL curves and none of the others. 2D library: OpenJDK has its own 2D library, different from the proprietary JDK. This means that its performance is different. Application Class Data Sharing is part of OpenJDK since OpenJDK 10. This feature reduces memory footprint by sharing class metadata. OpenJDK doesn't support the Resource Management API for Java. OpenJDK doesn't support the Simple Network Management Protocol API. OpenJDK has its own browser plugin and Java Web Start application (icedtea-web package). We wrote this independently of Oracle. Icedtea-web is currently supported on RHEL with OpenJDK 7 and 8 and adding Web Start support through it for Windows with OpenJDK 8 is in progress. OpenJDK doesn't support Cooperative Memory Management. This allows the user to tune the G1 garbage collector depending on a compromise between memory usage and performance. OpenJDK supports system-tap. OpenJDK is provided with full-debug clone-build (-debug- subpackages). OpenJDK comes with javadocs. Both zipped and uncompressed. OpenJDK is delivered with full sources. OpenJDK uses system tzdata and system certificates (Oracle has these bundle). OpenJDK 8 and 11 from Red Hat fully support Shenandoah, an low pausetime Garbage Collector for large heaps.