Our compatibility guidelines do not allow dropping support for a Java version in a minor or patch release by introducing code that won't link with the older runtime: http://hbase.apache.org/book.html#hbase.versioning
See the Dependency Compatibility section in particular. An upgrade of HBase will not require an incompatible upgrade of a dependent project, including the Java runtime. > On Sep 8, 2016, at 9:19 PM, 张铎 <[email protected]> wrote: > > So all the asynchronous api will be introduced in 2.0 only? > > And java7 has been end of life for more than one year... > And also, for a upgrade, I do not think it is a good idea to upgrade JDK > and HBase together. So you always need to upgrade to jdk8 or later first at > some time before upgrading to a jdk8 only HBase version, no matter you want > to upgrade to 2.0 or 1.4, this does not change. > > 2016-09-09 12:01 GMT+08:00 Ted Yu <[email protected]>: > >> Yeah, we should keep support for Java 7 in branch-1. >> >> We can use CompletableFuture for 2.0 release. >> >> On Thu, Sep 8, 2016 at 8:56 PM, Andrew Purtell <[email protected]> >> wrote: >> >>> I think we should wait until 2.0 before dropping support for less than >> JDK >>> 8. That's a pretty big deal. But, for 2.0, that would be fine IMHO. >>> >>>> On Sep 8, 2016, at 8:54 PM, Duo Zhang <[email protected]> wrote: >>>> >>>> The main reason is the asynchronous api we want to introduce in HBase >>>> today. See HBASE-13784 and HBASE-16505. >>>> >>>> The CompletableFuture in java8 is very suitable to use as the return >>> value >>>> of a async method. We can not use it if we still want to support java7, >>> and >>>> sadly, there is no candidate which is good enough to replace >>>> CompletableFuture. ListenableFuture in guava or Promise in netty are >>> good, >>>> but we do not want to expose third-party classes in our public >>>> API(especially guava, you know...). And we can also implement our own >>>> ListenableFuture but it just a copy of guava. Or introduce a simple >>>> Callback interface which does not need much code(for us) but this is a >>> code >>>> style around 2000s so people will not like it... >>>> >>>> And luckily, I found that in our documentation >>>> >>>> http://hbase.apache.org/book.html#basic.prerequisites >>>> >>>> We only say that 1.3 will be compatible with jdk7, not all 1.x. >>>> >>>> So here I propose that we drop the support of jdk7 in a future 1.x >>> release, >>>> maybe 1.4? Thus we can use CompletableFuture in both master and >> branch-1. >>>> >>>> Thanks. >>
