Where Do Java Class File Major Version Numbers Come From?

Major Version Numbers in Java Class File Format

Many developers are aware of the list of Java major version numbers, but they may not know where it originates. In this article, we'll explore the source of this list and provide additional insights into Java class file versions.

As mentioned in the user's query, Java class files store metadata including the major version number in their headers. This number indicates the compatibility of the class file with different versions of the Java Virtual Machine (JVM).

The major version number is located at byte offset 7 in a Java class file. It corresponds to the entry point version of the Java Platform, Micro Edition (JPME), that was used to compile the class. For example, a class file with a major version number of 66 indicates that it was compiled for JPME version 6.6.

The list of major version numbers, as provided in the user's query, is based on this information. It shows the mapping between Java versions and their corresponding major version numbers in the class file format.

While the list provides an overview of the major version numbers, it does not include minor versions. Minor versions are often associated with bug fixes and minor enhancements, but they do not typically affect the overall compatibility of class files.

For a more detailed reference on class file formats, including minor version information, you can refer to the following resources:

• [Java Class File Format](https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.1)
• [Oracle Java Technical Archives](https://docs.oracle.com/javase/specs/edr.html)

The above is the detailed content of Where Do Java Class File Major Version Numbers Come From?. For more information, please follow other related articles on the PHP Chinese website!