wsl 或者window terminal 下出现Java 14 switch expressions unrecognized解决方法：升级java jdk到14 or later

缘由解决方法参考

IDEA中build成功，但是automated build失败

$ ./gradlew

> Task :compileJava FAILED
Wordle/src/game/ui/Wordleframe.java:60: error: illegal start of expression
    var background = switch (tallyResultOfOneLetter) {
                     ^
Wordle/src/game/ui/Wordleframe.java:61: error: : expected
      case EXACT -> COLOR_OF_EXACT;
                                  ^
Wordle/src/game/ui/Wordleframe.java:62: error: : expected
      case MATCH -> COLOR_OF_MATCH;
                                  ^
Wordle/src/game/ui/Wordleframe.java:63: error: : expected
      case NO_MATCH -> COLOR_OF_NO_MATCH;
                                        ^
4 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
2 actionable tasks: 2 executed

后来发现IDEA中用的java JDK是17，而wsl中automated build用的是JDK 11，还没达到JDK14,所以无法识别14的表达式。

那就在wsl中升级JDK即可。

这里升级到Java17.

具体操作过程：wsl2下Ubuntu 20

首先输入

sudo apt update

如果ubuntu命令行出现 wsl ubuntu update显示err: 404 Not Found解决方法，请点击并且处理完之后再回到本文。

具体升级过程：

第一步：

sudo add-apt-repository ppa:linuxuprising/java

第二步：

sudo apt-get update
sudo apt-get install oracle-java17-installer oracle-java17-set-default

结果如下：

$ sudo apt-get install oracle-java17-installer oracle-java17-set-default
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  gsfonts gsfonts-x11 libxfont1 xfonts-encodings xfonts-utils
Suggested packages:
  binfmt-support visualvm ttf-baekmuk | ttf-unfonts | ttf-unfonts-core ttf-kochi-gothic | ttf-sazanami-gothic
  ttf-kochi-mincho | ttf-sazanami-mincho ttf-arphic-uming firefox | firefox-2 | iceweasel | mozilla-firefox
  | iceape-browser | mozilla-browser | epiphany-gecko | epiphany-webkit | epiphany-browser | galeon | midbrowser
  | moblin-web-browser | xulrunner | xulrunner-1.9 | konqueror | chromium-browser | midori | google-chrome
The following NEW packages will be installed:
  gsfonts gsfonts-x11 libxfont1 oracle-java17-installer oracle-java17-set-default xfonts-encodings xfonts-utils
0 upgraded, 7 newly installed, 0 to remove and 1 not upgraded.
Need to get 4158 kB of archives.
After this operation, 6408 kB of additional disk space will be used.
Do you want to continue? [Y/n]

出现的条款，pagedown键划到底下，用上下左右键选择下方的ok

然后按方向键选择yes，按enter回车。

然后就是开始下载

安装完成之后

azheng@lishizheng:/mnt/e/shizheng_coding/software_design_venkat$ java --version
java 17.0.1 2021-10-19 LTS
Java(TM) SE Runtime Environment (build 17.0.1+12-LTS-39)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)

[1]https://github.com/google/google-java-format/issues/535

[2]https://www.debugpoint.com/2021/09/install-java-17-ubuntu-mint/