Oracle limits Java 9 to Java 8 backward compatibility __java

As developers are excited to turn the JAVA8 Toolkit to JAVA9, Oracle's chief executive proposes to limit two versions of compatibility.

In an email from the OPENJDK mailing list in the afternoon of Monday, Mark Reinhold, chief architect of the Oracle Java platform, noted that more changes would be added to JDK8 (probably in early 2014), meaning JDK9 the "forest", a directory or a set of directories would soon come. So now developers are going to start thinking about how to deal with the changes in these two versions.

In general, they will make some changes in the new development version before adding to the old version. During the preparation period for releasing this new JDK8, more system integration tests were done than the new version, but this did not make much sense for the release of the new version. Because the new version will change first, it slows down the release of the final release.

Before that, when JDK7 was released, there were no strategies to deal with the problem of parallel change. A member of the Sun or Oracle team will be able to make a semi-automatic merge of the final version until the merge becomes impractical, and the developer's first time is to make improvements to the version that will be released. Developers will be asked to make improvements to these two versions at the same time. Then the data from the previously debugged database will be used to help improve the new version.

Reinhold also said, "This method is not good before, regardless of whether the semi-automatic merger is still in progress, it will require hundreds of developers to the new version of each phase of supervision and contribution." Once these mergers have stopped, they need to change the way they work together immediately. ”

To simplify the process of the final version, Reinhold points out that the development of JDK9 will begin initializing in a particular JDK8 construct. "After the construction is complete, the two versions are no longer allowed to merge. Developers should also make changes to the JDK8 when making changes to the JDK9, if that change applies to JDK9.

Reinhold hopes these changes will rectify the entire development process. "I think the only downside is that it can't reconstruct the JDK8 ga from JDK9 because it was separated from the GA before JDK8 ga." If I can do this, I feel very convenient and cool, which is more aesthetically valuable than technology. This situation is the same as not having a new version of the JDK7 that you can't build from JDK8. ”

To make it easier to encode on multi-core processors, the java-based standard version 8,JDK 8 is designed to support the Lambda project, and the preview build is ready for use. The subsequent JDK versions, expected to be released early in 2016, will add to the features of the project Jigsaw and Java modularity.