Chapter 3. OpenJDK features

The latest OpenJDK 11 release might include new features. Additionally, the latest release might enhance, deprecate, or remove features that originated from previous OpenJDK 11 releases.

Note

For all the other changes and security fixes, see OpenJDK 11.0.20 Released.

OpenJDK new features and enhancements

Review the following release notes to understand new features and feature enhancements that are included with the OpenJDK 11.0.20 release:

Reduced risk of JVM crash when using GregorianCalendar.computeTime()

In OpenJDK 11.0.19, a virtual machine crash could occur when using the GregorianCalendar.computeTime() method (JDK-8307683). Even though an old issue is the root cause of this JVM crash, a recent fix for a rare issue in the C2 compiler (JDK-8297951) significantly increased the probability of the JVM crash. To mitigate risk, the OpenJDK 11.0.20 release excludes the fix for the C2 compiler. Once the root cause of the JVM crash is resolved (JDK-8307683), OpenJDK will reintroduce the fix for the C2 compiler (JDK-8297951).

See JDK-8308884 (JDK Bug System).

Additional characters for GB18030-2022 support allowed

To support "Implementation Level 1" of the GB18030-2022 standard, OpenJDK must support the use of five additional characters that are beyond the scope of Unicode 10, which OpenJDK 11 is based on. Maintenance Release 2 of the Java SE 11 specification adds support for these additional characters, which OpenJDK 11.0.20 implements.

The additional characters are as follows:

  • 0x82359632 U+9FEB
  • 0x82359633 U+9FEC
  • 0x82359634 U+9FED
  • 0x82359635 U+9FEE
  • 0x82359636 U+9FEF

See JDK-8301401 (JDK Bug System).

Support for GB18030-2022

The Chinese Electronics Standardization Institute (CESI) recently published GB18030-2022 as an update to the GB18030 standard, synchronizing the character set with Unicode 11.0. The GB18030-2022 standard is now the default GB18030 character set that OpenJDK 11.0.20 uses. However, this updated character set contains incompatible changes compared with GB18030-2000, which previous releases of OpenJDK 11 used. From OpenJDK 11.0.20 onward, if you want to use the previous version of the character set, ensure that the new system property jdk.charset.GB18030 is set to 2000.

See JDK-8301119 (JDK Bug System).

Enhanced ZIP performance

The OpenJDK 11.0.20 release includes enhanced checks on the ZIP64 fields of .zip files. If these checks cause failures on trusted .zip files, you can disable these checks by setting the new system property jdk.util.zip.disableZip64ExtraFieldValidation to true.

JDK bug system reference ID: JDK-8302483.

Enhanced validation of JAR signature

You can now configure the maximum number of bytes that are allowed for the signature-related files in a Java archive (JAR) file by setting a new system property, jdk.jar.maxSignatureFileSize. By default, the jdk.jar.maxSignatureFileSize property is set to 8000000 bytes (8 MB).

JDK bug system reference ID: JDK-8300596.

The javadoc tool now supports the inclusion of legal files, which pertain to the licensing of files that the standard doclet generates. You can use the new --legal-notices command-line option to configure this feature.

See JDK-8259530 (JDK Bug System).

GTS root certificate authority (CA) certificates added

In the OpenJDK 11.0.20 release, the cacerts truststore includes four Google Trust Services (GTS) root certificates:

Certificate 1
  • Name: Google Trust Services LLC
  • Alias name: gtsrootcar1
  • Distinguished name: CN=GTS Root R1, O=Google Trust Services LLC, C=US
Certificate 2
  • Name: Google Trust Services LLC
  • Alias name: gtsrootcar2
  • Distinguished name: CN=GTS Root R2, O=Google Trust Services LLC, C=US
Certificate 3
  • Name: Google Trust Services LLC
  • Alias name: gtsrootcar3
  • Distinguished name: CN=GTS Root R3, O=Google Trust Services LLC, C=US
Certificate 4
  • Name: Google Trust Services LLC
  • Alias name: gtsrootcar4
  • Distinguished name: CN=GTS Root R4, O=Google Trust Services LLC, C=US

See JDK-8307134 (JDK Bug System).

Microsoft Corporation root CA certificates added

In the OpenJDK 11.0.20 release, the cacerts truststore includes two Microsoft Corporation root certificates:

Certificate 1
  • Name: Microsoft Corporation
  • Alias name: microsoftecc2017
  • Distinguished name: CN=Microsoft ECC Root Certificate Authority 2017, O=Microsoft Corporation, C=US
Certificate 2
  • Name: Microsoft Corporation
  • Alias name: microsoftrsa2017
  • Distinguished name: CN=Microsoft RSA Root Certificate Authority 2017, O=Microsoft Corporation, C=US

See JDK-8304760 (JDK Bug System).

TWCA root CA certificate added

In the OpenJDK 11.0.20 release, the cacerts truststore includes the Taiwan Certificate Authority (TWCA) root certificate:

  • Name: TWCA
  • Alias name: twcaglobalrootca
  • Distinguished name: CN=TWCA Global Root CA, OU=Root CA, O=TAIWAN-CA, C=TW

See JDK-8305975 (JDK Bug System).