The Java language has undergone several changes since JDK 1.0 as well as numerous additions of classes and packages to the standard library. Since J2SE 1.4, the evolution of the Java language has been governed by the Java Community Process (JCP), which uses Java Specification Requests (JSRs) to propose and specify additions and changes to the Java platform. The language is specified by the Java Language Specification (JLS); changes to the JLS are managed under JSR 901. In September 2017, Mark Reinhold, chief Architect of the Java Platform, proposed to change the release train to "one feature release every six months" rather than the then-current two-year schedule.^[1][2] This proposal took effect for all following versions, and is still the current release schedule.

In addition to the language changes, other changes have been made to the Java Class Library over the years, which has grown from a few hundred classes in JDK 1.0 to over three thousand in J2SE 5. Entire new APIs, such as Swing and Java2D, have been introduced, and many of the original JDK 1.0 classes and methods have been deprecated, and very few APIs have been removed (at least one, for threading, in Java 22^[3]). Some programs allow the conversion of Java programs from one version of the Java platform to an older one (for example Java 5.0 backported to 1.4) (see Java backporting tools).

Regarding Oracle Java SE Support Roadmap,^[4] version 22 is the latest one, and versions 21, 17, 11 and 8 are the currently supported long-term support (LTS) versions, where Oracle Customers will receive Oracle Premier Support. Oracle continues to release no-cost public Java 8 updates for development^[4] and personal use indefinitely. Oracle also continues to release no-cost public Java 17 LTS updates for all users, including commercial and production use until September 2024.^[5]

In the case of OpenJDK, both commercial long-term support and free software updates are available from multiple organizations in the broader community.^[6]

Java 22 was released on March 19, 2024.

Release table

JDK 1.0

The first version was released on January 23, 1996.^[15][16] The first stable version, JDK 1.0.2, is called Java 1.^[16]

JDK 1.1

Major additions in the release on February 19, 1997 included:^[17]

• extensive retooling of the Abstract Window Toolkit (AWT) event model
• inner classes added to the language
• JavaBeans
• Java Database Connectivity (JDBC)
• Java remote method invocation (RMI) and serialization
• reflection which supported Introspection only, no modification at runtime was possible. (The ability to modify objects reflectively was added in J2SE 1.2, by introducing the AccessibleObject class and its subclasses such as the Field class.)
• Just-in-time compilation (JIT) on Microsoft Windows platforms, produced for JavaSoft by Symantec
• Internationalization and Unicode support originating from Taligent^[18]

J2SE 1.2

The release on December 8, 1998 and subsequent releases through J2SE 5.0 were rebranded retrospectively Java 2 and the version name "J2SE" (Java 2 Platform, Standard Edition) replaced JDK to distinguish the base platform from J2EE (Java 2 Platform, Enterprise Edition) and J2ME (Java 2 Platform, Micro Edition). This was a very significant release of Java as it tripled the size of the Java platform to 1520 classes in 59 packages. Major additions included:^[19]

• strictfp keyword (by JVM 17 an obsolete keyword, should not be used in new code)
• The Swing graphical API was integrated into the core classes.
• Sun's JVM was equipped with a JIT compiler for the first time.
• Java plug-in
• Java IDL, an IDL implementation for CORBA interoperability
• Collections framework

J2SE 1.3

The most notable changes in the May 8, 2000 release were:^[20][21]

• HotSpot JVM included (the HotSpot JVM was first released in April 1999 for the J2SE 1.2 JVM)
• RMI was modified to support optional compatibility with CORBA.
• Java Naming and Directory Interface (JNDI) included in core libraries (previously available as an extension)
• Java Platform Debugger Architecture (JPDA)
• JavaSound
• Synthetic proxy classes

Java 1.3 is the last release of Java to officially support Microsoft Windows 95.^[22]

J2SE 1.4

The February 6, 2002 release was the first release of the Java platform developed under the Java Community Process as JSR 59. Major changes included:^[23][24]

• Language changes
  • assert keyword (specified in JSR 41)
• Library improvements
  • Regular expressions modeled after Perl regular expressions
  • Exception chaining allows an exception to encapsulate original lower-level exception
  • Internet Protocol version 6 (IPv6) support
  • Non-blocking I/O (named NIO) (specified in JSR 51)
  • Logging API (specified in JSR 47)
  • Image I/O API for reading and writing images in formats like JPEG and PNG
  • Integrated XML parser and XSLT processor (JAXP) (specified in JSR 5 and JSR 63)
  • Integrated security and cryptography extensions (JCE, JSSE, JAAS)
  • Java Web Start included (Java Web Start was first released in March 2001 for J2SE 1.3) (specified in JSR 56)
  • Preferences API (java.util.prefs)

Public support and security updates for Java 1.4 ended in October 2008. Paid security updates for Oracle customers ended in February 2013.^[25]

Java SE 5

The release on September 30, 2004 was originally numbered 1.5, which is still used as the internal version number. The number was changed to "better reflect the level of maturity, stability, scalability and security of the J2SE".^[26] This version was developed under JSR 176.

Java SE 5 entered its end-of-public-updates period on April 8, 2008; updates are no longer available to the public as of November 3, 2009. Updates were available to paid Oracle customers until May 2015.^[4]

Tiger added a number of significant new language features:^[27][28]

• Generics: provides compile-time (static) type safety for collections and eliminates the need for most typecasts (type conversion) (specified by JSR 14)
• Metadata: also called annotations; allows language constructs such as classes and methods to be tagged with additional data, which can then be processed by metadata-aware utilities (specified by JSR 175)
• Autoboxing/unboxing: automatic conversions between primitive types (such as int) and primitive wrapper classes (such as Integer) (specified by JSR 201)
• Enumerations: the enum keyword creates a typesafe, ordered list of values (such as Day.MONDAY, Day.TUESDAY, etc.); previously this could only be achieved by non-typesafe constant integers or manually constructed classes (typesafe enum pattern) (specified by JSR 201)
• Varargs: the last parameter of a method can now be declared using a type name followed by three dots (e.g. void drawtext(String... lines)); in the calling code any number of parameters of that type can be used and they are then placed in an array to be passed to the method, or alternatively the calling code can pass an array of that type
• Enhanced for each loop: the for loop syntax is extended with special syntax for iterating over each member of either an array or any Iterable, such as the standard Collection classes (specified by JSR 201)
• Improved semantics of execution for multi-threaded Java programs; the new Java memory model addresses issues of complexity, effectiveness, and performance of previous specifications^[29]
• Static imports

There were also the following improvements to the standard libraries:

• Automatic stub generation for RMI objects
• Swing: New skinnable look and feel, called synth
• The concurrency utilities in package java.util.concurrent^[30]
• Scanner class for parsing data from various input streams and buffers

Java 5 is the last release of Java to officially support Microsoft Windows 98 and Windows ME,^[31] while Windows Vista was the newest version of Windows that Java SE 5 was supported on prior to Java 5 going end-of-life in October of 2009.^[25]

Java 5 Update 5 (1.5.0_05) is the last release of Java to work on Windows 95 (with Internet Explorer 5.5 installed) and Windows NT 4.0.^[32]

Java 5 was first available on Apple Mac OS X 10.4 (Tiger)^[33] and was the default version of Java installed on Apple Mac OS X 10.5 (Leopard).

Public support and security updates for Java 1.5 ended in November 2009. Paid security updates for Oracle customers ended in April 2015.

Versioning change

This version introduced a new versioning system for the Java language, although the old versioning system continued to be used for developer libraries:

Both version numbers "1.5.0" and "5.0" are used to identify this release of the Java 2 Platform Standard Edition. Version "5.0" is the product version, while "1.5.0" is the developer version. The number "5.0" is used to better reflect the level of maturity, stability, scalability and security of the J2SE.

— "Version 1.5.0 or 5.0?", Java release notes^[34]

This correspondence continued through later releases (Java 6 = JDK 1.6, Java 7 = JDK 1.7, and so on).

Java SE 6

As of the version released on December 11, 2006, Sun replaced the name "J2SE" with Java SE and dropped the ".0" from the version number.^[35] Internal numbering for developers remains 1.6.0.^[36]

This version was developed under JSR 270.

During the development phase, new builds including enhancements and bug fixes were released approximately weekly. Beta versions were released in February and June 2006, leading up to a final release that occurred on December 11, 2006.

Major changes included in this version:^[37][38]

• Support for older Win9x versions dropped; unofficially, Java 6 Update 7 was the last release of Java shown to work on these versions of Windows.^{[citation needed]} This is believed^{[by whom?]} to be due to the major changes in Update 10.
• Scripting Language Support (JSR 223): Generic API for tight integration with scripting languages, and built-in Mozilla JavaScript Rhino integration.
• Dramatic performance improvements for the core platform,^[39][40] and Swing.
• Improved Web Service support through JAX-WS (JSR 224).
• JDBC 4.0 support (JSR 221).
• Java Compiler API (JSR 199): an API allowing a Java program to select and invoke a Java Compiler programmatically.
• Upgrade of JAXB to version 2.0: Including integration of a StAX parser.
• Support for pluggable annotations (JSR 269).^[41]
• Many GUI improvements, such as integration of SwingWorker in the API, table sorting and filtering, and true Swing double-buffering (eliminating the gray-area effect).
• JVM improvements include: synchronization and compiler performance optimizations, new algorithms and upgrades to existing garbage collection algorithms, and application start-up performance.

Java 6 can be installed to Mac OS X 10.5 (Leopard) running on 64-bit (Core 2 Duo and higher) processor machines.^[42] Java 6 is also supported by both 32-bit and 64-bit machines running Mac OS X 10.6 (Snow Leopard).

Java 6 reached the end of its supported life in February 2013, at which time all public updates, including security updates, were scheduled to be stopped.^[43][44] Oracle released two more updates to Java 6 in March and April 2013, which patched some security vulnerabilities.^[45][46]

Java 6 updates

After Java 6 release, Sun, and later Oracle, released several updates which, while not changing any public API, enhanced end-user usability or fixed bugs.^[47]

Java SE 7

Java 7 was a major update that launched on July 7, 2011^[85] and was made available for developers on July 28, 2011.^[86] The development period was organized into thirteen milestones; on June 6, 2011, the last of the thirteen milestones was finished.^[86][87] On average, 8 builds (which generally included enhancements and bug fixes) were released per milestone. The feature list at the OpenJDK 7 project lists many of the changes.

Additions in Java 7 include:^[88]

• JVM support for dynamic languages, with the new invokedynamic bytecode under JSR-292,^[89] following the prototyping work currently done on the Multi Language Virtual Machine
• Compressed 64-bit pointers^[90] (available in Java 6 with -XX:+UseCompressedOops)^[91]
• These small language changes (grouped under a project named Coin):^[92]

• Strings in switch^[93]
• Automatic resource management in try-statement aka try-with-resources statement^[94]
• Improved type inference for generic instance creation, aka the diamond operator <>^[95]
• Simplified varargs method declaration^[96]
• Binary integer literals^[97]
• Allowing underscores in numeric literals^[98]
• Catching multiple exception types and rethrowing exceptions with improved type checking^[99]

• Concurrency utilities under JSR 166^[100]
• New file I/O library (defined by JSR 203) adding support for multiple file systems, file metadata and symbolic links. The new packages are java.nio.file, java.nio.file.attribute and java.nio.file.spi^[101][102]
• Timsort is used to sort collections and arrays of objects instead of merge sort
• Library-level support for elliptic curve cryptography algorithms
• An XRender pipeline for Java 2D, which improves handling of features specific to modern GPUs
• New platform APIs for the graphics features originally implemented in version 6u10 as unsupported APIs^[103]
• Enhanced library-level support for new network protocols, including SCTP and Sockets Direct Protocol
• Upstream updates to XML and Unicode
• Java deployment rule sets^[104]

Lambda (Java's implementation of lambda functions), Jigsaw (Java's implementation of modules), and part of Coin were dropped from Java 7, and released as part of Java 8 (except for Jigsaw, which was released in Java 9).^[105][106]

Java 7 was the default version to download on java.com from April 2012 until Java 8 was released.^[107]

Java 7 updates

Oracle issued public updates to the Java 7 family on a quarterly basis^[108] until April 2015 when the product reached the end of its public availability.^[109] Further updates for JDK 7, which continued until July 2022, are only made available to customers with a support contract.^[110]