title: Firebase Tools and Java 11
body: <p>This question falls somewhere between Firebase Tools, MacOS and Java. Probably 75% Java, 20% Firebase Tools and 5% MacOS.</p>
  <p>Starting with v10.5, firebase-tools started stating that 'Support for Java version &lt;= 10 will be dropped soon in firebase-tools@11. Please upgrade to Java version 11 or above to continue using the emulators.'</p>
  <p>I run macOS v11.6.5 on a Macbook Pro from mid-2014. When I go to <a href="https://www.java.com/en/download/" rel="noreferrer">Java's Downloads page</a>, it recommends Java 'Version 8 Update 331'. Not Java 11.</p>
  <p>Information on downloading Java 11 seems to be scarce. Oracle's <a href="https://www.oracle.com/java/technologies/javase/products-doc-jdk11certconfig.html" rel="noreferrer">page of certified configurations</a> includes MacOS 11, but I can't find anywhere obvious where Java 11 can be readily downloaded.</p>
  <p>A big part of the problem seems to be the terminology used. If I run <code>java -version</code>, I get:</p>
  <pre><code>java version &quot;1.8.0_331&quot;
  Java(TM) SE Runtime Environment (build 1.8.0_331-b09)
  Java HotSpot(TM) 64-Bit Server VM (build 25.331-b09, mixed mode)
  </code></pre>
  <p>Okay, I have build 1.8 of the Java Runtime Environment, aka the JRE if you are a Java enthusiast. <a href="https://github.com/firebase/firebase-tools/pull/4347/commits/9c2029cd0ed650a0403fb73ffe5bb1a8b989597f#diff-a1ad4cf0c9fac1cb8905b5f41ced4ca7dab42af061d383305738cc514a7923f3R442" rel="noreferrer">That</a> is apparently what is triggering the warning in Firebase Tools.</p>
  <p>There is also a Java product out there called 'Java SE 11'. The product itself is ambiguous, but the <a href="https://www.oracle.com/a/tech/docs/11-0-15-1-checksum.html" rel="noreferrer">checksums</a> all say 'SDK'. (A Software Development Kit: a thing that enables developers to develop Java programs. The name doesn't imply a Runtime Environment: a thing that enables Java to run on an operating system.) There is <a href="https://java.tutorials24x7.com/blog/how-to-install-java-11-on-mac" rel="noreferrer">an article</a> out there which claims that, if you <a href="https://www.oracle.com/java/technologies/downloads/#java11" rel="noreferrer">install Java SE 11</a> and run <code>java -version</code>, it will spit out <code>java version &quot;11.0.7&quot;</code>. That will probably satisfy Firebase Tools.</p>
  <p>But <a href="https://www.oracle.com/java/technologies/javase/11-relnote-issues.html" rel="noreferrer">Oracle's release notes</a> say: 'In Windows and macOS, installing the JDK in previous releases optionally installed a JRE. In JDK 11, this is no longer an option.' No longer an option... as in now you implicitly get JRE 11 with SDK 11? Or as in the SDK and JRE are now fully divorced, and the JRE must be ferreted out of its hiding like a wild beast?</p>
  <p>UPDATE 6/5/22: Java's checksums page now says 'JDK', and I guess that is better than 'SDK' because it implies 'Java Development Kit', which <a href="https://en.wikipedia.org/wiki/Java_Development_Kit" rel="noreferrer">this Wikipedia article</a> claims to include both a JRE ('java') and SDK (most of the other files).</p>