問題描述

由于最近 Oracle Java SE 支持路線圖 政策更新(特別是在 2019 年 3 月之后來自 Oracle 的免費版本更新結束)，我一直在尋找 Oracle Java 的替代品.我發現 OpenJDK 是一種開源替代方案.我發現 AdoptOpenJDK, 現在稱為 Adoptium，它是一個預構建的二進制文件.它令人困惑.

OpenJDK和Adoptium/AdoptOpenJDK有什么區別?

總之:

• OpenJDK有多種含義，可以參考:
  • Java 平臺標準版 (Java SE) 的免費開源實現
  • 開源存儲庫 — Java 源代碼，即 OpenJDK 項目
  • 由 Oracle 維護的預構建 OpenJDK 二進制文件
  • 由 OpenJDK 社區維護的預構建 OpenJDK 二進制文件
• AdoptOpenJDK — 由社區維護的預構建 OpenJDK 二進制文件(開源許可)

解釋:

Prebuilt OpenJDK(或分發版)- 二進制文件，從 http://hg 構建.openjdk.java.net/，作為存檔或安裝程序提供，適用于各種平臺，可能有支持合同.

OpenJDK，源代碼庫(也稱為 OpenJDK 項目) - 是一個 Mercurial 基于開源存儲庫，托管在http://hg.openjdk.java.net.Java 源代碼.絕大多數 Java 功能(從 VM 和核心庫到編譯器)僅基于此源存儲庫.Oracle 有一個替代分支.

OpenJDK，分發版(請參閱下面的提供者列表)- 免費就像在啤酒中 和那種 像在演講中一樣自由，但是，你沒有得到如果您遇到問題，請致電 Oracle.沒有支持合同.此外，如果 OpenJDK(發行版)版本是最新的 Java 版本，包括 LTS(長期支持)版本，Oracle 只會發布該版本的更新.Oracle 發布 OpenJDK(發行版)12.0 版的當天，即使 OpenJDK(發行版)11.0 版存在安全問題，Oracle 也不會發布 11.0 的更新.由 Oracle 單獨維護.

一些 OpenJDK 項目 - 例如 OpenJDK 8 和 OpenJDK 11 - 由 OpenJDK 社區維護，并為某些平臺的某些 OpenJDK 版本提供發布.社區成員負責為這些 OpenJDK 版本中的安全漏洞發布修復程序.

AdoptOpenJDK，發行版與 Oracle 的 OpenJDK 發行版非常相似(因為它是免費的，并且是通過編譯來自 OpenJDK 源代碼庫的源代碼生成的構建).AdoptOpenJDK 作為一個實體不會向后移植補丁，即不會有與上游有本質不同的 AdoptOpenJDK 'fork/version'(除了一些構建腳本補丁，如 Win32 支持).這意味著，如果社區成員(Oracle 或其他人，但不是 AdoptOpenJDK 作為一個實體)將安全修復程序向后移植到 OpenJDK LTS 版本的更新，那么 AdoptOpenJDK 將為這些版本提供構建.由 OpenJDK 社區維護.

OracleJDK - 又一個發行版.從 JDK12 開始，將不再有 OracleJDK 的免費版本.Oracle 的 JDK 分發產品旨在提供商業支持.您為此付費，但隨后您將依賴 Oracle 提供支持.與 Oracle 的 OpenJDK 產品不同，OracleJDK 為 LTS 版本提供了更長的支持.作為開發人員，您可以獲得僅用于個人/開發使用此特定 JDK 的免費許可證，但這主要是一個紅鯡魚，因為只是二進制文件"與 OpenJDK 二進制文件基本相同.我猜這意味著你可以從 Oracle 的網站下載 LTS JDK 的安全補丁版本，只要你保證不將它們用于商業用途.

注意.最好將 Oracle 的 OpenJDK 構建稱為Oracle OpenJDK 構建".

Donald Smith，Oracle 的 Java 產品經理 寫:

理想情況下，我們會簡單地將所有 Oracle JDK 構建稱為Oracle JDK"，根據 GPL 或商業許可，取決于您的情況.然而，由于歷史原因，雖然剩下的小存在差異，我們將它們分別稱為 Oracle 的OpenJDK 構建和 Oracle JDK.

<小時>

OpenJDK 提供程序和比較

• 采用OpenJDK - https://adoptopenjdk.net
• 亞馬遜 – Corretto - https://aws.amazon.com/corretto
• Azul Zulu - https://www.azul.com/downloads/zulu/
• BellSoft Liberica - https://bell-sw.com/java.html
• IBM - https://www.ibm.com/developerworks/java/jdk
• jClarity - https://www.jclarity.com/adoptopenjdk-支持/
• OpenJDK 上游 - https://adoptopenjdk.net/upstream.html
• Oracle JDK - https://www.oracle.com/technetwork/java/javase/downloads
• Oracle OpenJDK - http://jdk.java.net
• ojdkbuild - https://github.com/ojdkbuild/ojdkbuild
• RedHat - https://developers.redhat.com/products/openjdk/概述
• SapMachine - https://sap.github.io/SapMachine

_{源代碼免費構建 - 分發源代碼是公開可用的，可以組裝自己的構建}

_{免費二進制分發版 - 分發版二進制文件可公開下載和使用}

_{擴展更新 - 又名 LTS(長期支持) - 超過 6 個月發布生命周期的公共更新}

_{商業支持 - 一些提供商為付費客戶提供擴展更新和客戶支持，例如Oracle JDK(支持詳情)}

_{Permissive License - 分發許可證是非保護性的，例如阿帕奇 2.0}

我應該使用哪個 Java 發行版?

在 Sun/Oracle 時代，通常是 Sun/Oracle 生產基于 OpenJDK 源的專有下游 JDK 發行版.最近，Oracle 決定僅在附帶商業支持的情況下進行自己的專有構建.他們還慷慨地在其 https://jdk.java.net/ 站點上發布了 OpenJDK 構建.p>

從 JDK 11 開始發生的事情是從單一供應商 (Oracle) 思維模式轉變為在你喜歡的條件下選擇提供產品分發的供應商的思維模式:他們構建的平臺、頻率和發布的及時性、支持的結構等.如果您不信任任何現有供應商，您甚至可以自己構建 OpenJDK.

OpenJDK 的每個構建通常都來自相同的原始上游源代碼庫(OpenJDK項目").然而，每個構建都非常獨特 - 免費或商業、品牌或非品牌、純或捆綁(例如，BellSoft Liberica JDK 提供捆綁的 JavaFX，從 JDK 11 開始的 Oracle 構建中刪除了它).

如果沒有環境(例如，Linux)和/或許可證要求定義特定的分發，并且如果您想要最標準 JDK 構建，那么最好的選擇可能是使用 Oracle 的 OpenJDK 或 AdoptOpenJDK.

其他信息

是時候超越 Oracle 的 JDK 了斯蒂芬·科爾伯恩(Stephen Colebourne)

Java 仍然免費，由 Java Champions 社區(發布于2018 年 9 月 17 日)

Java 仍然是免費的 2.0.0 由 Java Champions 社區提供(2019 年 3 月 3 日發布)

Aleksey Shipilev 關于 JDK 更新 Opsian 采訪(發布于 2019 年 6 月 27 日)

Due to recent Oracle Java SE Support Roadmap policy update (end of $free release updates from Oracle after March 2019 in particular), I've been searching for alternatives to Oracle Java. I've found that OpenJDK is an open-source alternative. And I've found AdoptOpenJDK, now known as Adoptium, which is a prebuilt binary. It puzzles.

What is the difference between OpenJDK and Adoptium/AdoptOpenJDK?

In short:

• OpenJDK has multiple meanings and can refer to:
  • free and open source implementation of the Java Platform, Standard Edition (Java SE)
  • open source repository — the Java source code aka OpenJDK project
  • prebuilt OpenJDK binaries maintained by Oracle
  • prebuilt OpenJDK binaries maintained by the OpenJDK community
• AdoptOpenJDK — prebuilt OpenJDK binaries maintained by community (open source licensed)

Explanation:

Prebuilt OpenJDK (or distribution) — binaries, built from http://hg.openjdk.java.net/, provided as an archive or installer, offered for various platforms, with a possible support contract.

OpenJDK, the source repository (also called OpenJDK project) - is a Mercurial-based open source repository, hosted at http://hg.openjdk.java.net. The Java source code. The vast majority of Java features (from the VM and the core libraries to the compiler) are based solely on this source repository. Oracle have an alternate fork of this.

OpenJDK, the distribution (see the list of providers below) - is free as in beer and kind of free as in speech, but, you do not get to call Oracle if you have problems with it. There is no support contract. Furthermore, Oracle will only release updates to any OpenJDK (the distribution) version if that release is the most recent Java release, including LTS (long-term support) releases. The day Oracle releases OpenJDK (the distribution) version 12.0, even if there's a security issue with OpenJDK (the distribution) version 11.0, Oracle will not release an update for 11.0. Maintained solely by Oracle.

Some OpenJDK projects - such as OpenJDK 8 and OpenJDK 11 - are maintained by the OpenJDK community and provide releases for some OpenJDK versions for some platforms. The community members have taken responsibility for releasing fixes for security vulnerabilities in these OpenJDK versions.

AdoptOpenJDK, the distribution is very similar to Oracle's OpenJDK distribution (in that it is free, and it is a build produced by compiling the sources from the OpenJDK source repository). AdoptOpenJDK as an entity will not be backporting patches, i.e. there won't be an AdoptOpenJDK 'fork/version' that is materially different from upstream (except for some build script patches for things like Win32 support). Meaning, if members of the community (Oracle or others, but not AdoptOpenJDK as an entity) backport security fixes to updates of OpenJDK LTS versions, then AdoptOpenJDK will provide builds for those. Maintained by OpenJDK community.

OracleJDK - is yet another distribution. Starting with JDK12 there will be no free version of OracleJDK. Oracle's JDK distribution offering is intended for commercial support. You pay for this, but then you get to rely on Oracle for support. Unlike Oracle's OpenJDK offering, OracleJDK comes with longer support for LTS versions. As a developer you can get a free license for personal/development use only of this particular JDK, but that's mostly a red herring, as 'just the binary' is basically the same as the OpenJDK binary. I guess it means you can download security-patched versions of LTS JDKs from Oracle's websites as long as you promise not to use them commercially.

Note. It may be best to call the OpenJDK builds by Oracle the "Oracle OpenJDK builds".

Donald Smith, Java product manager at Oracle writes:

Ideally, we would simply refer to all Oracle JDK builds as the "Oracle JDK", either under the GPL or the commercial license, depending on your situation. However, for historical reasons, while the small remaining differences exist, we will refer to them separately as Oracle’s OpenJDK builds and the Oracle JDK.

OpenJDK Providers and Comparison

• AdoptOpenJDK - https://adoptopenjdk.net
• Amazon – Corretto - https://aws.amazon.com/corretto
• Azul Zulu - https://www.azul.com/downloads/zulu/
• BellSoft Liberica - https://bell-sw.com/java.html
• IBM - https://www.ibm.com/developerworks/java/jdk
• jClarity - https://www.jclarity.com/adoptopenjdk-support/
• OpenJDK Upstream - https://adoptopenjdk.net/upstream.html
• Oracle JDK - https://www.oracle.com/technetwork/java/javase/downloads
• Oracle OpenJDK - http://jdk.java.net
• ojdkbuild - https://github.com/ojdkbuild/ojdkbuild
• RedHat - https://developers.redhat.com/products/openjdk/overview
• SapMachine - https://sap.github.io/SapMachine

----------------------------------------------------------------------------------------
|     Provider      | Free Builds | Free Binary   | Extended | Commercial | Permissive |
|                   | from Source | Distributions | Updates  | Support    | License    |
|--------------------------------------------------------------------------------------|
| AdoptOpenJDK      |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Amazon – Corretto |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Azul Zulu         |    No       |    Yes        |   Yes    |   Yes      |   Yes      |
| BellSoft Liberica |    No       |    Yes        |   Yes    |   Yes      |   Yes      |
| IBM               |    No       |    No         |   Yes    |   Yes      |   Yes      |
| jClarity          |    No       |    No         |   Yes    |   Yes      |   Yes      |
| OpenJDK           |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Oracle JDK        |    No       |    Yes        |   No**   |   Yes      |   No       |
| Oracle OpenJDK    |    Yes      |    Yes        |   No     |   No       |   Yes      |
| ojdkbuild         |    Yes      |    Yes        |   No     |   No       |   Yes      |
| RedHat            |    Yes      |    Yes        |   Yes    |   Yes      |   Yes      |
| SapMachine        |    Yes      |    Yes        |   Yes    |   Yes      |   Yes      |
----------------------------------------------------------------------------------------

_{Free Builds from Source - the distribution source code is publicly available and one can assemble its own build}

_{Free Binary Distributions - the distribution binaries are publicly available for download and usage}

_{Extended Updates - aka LTS (long-term support) - Public Updates beyond the 6-month release lifecycle}

_{Commercial Support - some providers offer extended updates and customer support to paying customers, e.g. Oracle JDK (support details)}

_{Permissive License - the distribution license is non-protective, e.g. Apache 2.0}

Which Java Distribution Should I Use?

In the Sun/Oracle days, it was usually Sun/Oracle producing the proprietary downstream JDK distributions based on OpenJDK sources. Recently, Oracle had decided to do their own proprietary builds only with the commercial support attached. They graciously publish the OpenJDK builds as well on their https://jdk.java.net/ site.

What is happening starting JDK 11 is the shift from single-vendor (Oracle) mindset to the mindset where you select a provider that gives you a distribution for the product, under the conditions you like: platforms they build for, frequency and promptness of releases, how support is structured, etc. If you don't trust any of existing vendors, you can even build OpenJDK yourself.

Each build of OpenJDK is usually made from the same original upstream source repository (OpenJDK "the project"). However each build is quite unique - $free or commercial, branded or unbranded, pure or bundled (e.g., BellSoft Liberica JDK offers bundled JavaFX, which was removed from Oracle builds starting JDK 11).

If no environment (e.g., Linux) and/or license requirement defines specific distribution and if you want the most standard JDK build, then probably the best option is to use OpenJDK by Oracle or AdoptOpenJDK.

Additional information

Time to look beyond Oracle's JDK by Stephen Colebourne

Java Is Still Free by Java Champions community (published on September 17, 2018)

Java is Still Free 2.0.0 by Java Champions community (published on March 3, 2019)

Aleksey Shipilev about JDK updates interview by Opsian (published on June 27, 2019)

這篇關于OpenJDK 和 Adoptium/AdoptOpenJDK 的區別的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！