Ubuntu Linux下无法切换Java版本的问题求助与解决

我在Ubuntu 22.04.2 LTS系统的.bashrc文件中设置了JAVA_HOME，但执行java -version时仍然显示旧版本：

ruomini@ruomini-XPS-13-9370:~$ echo $JAVA_HOME
/home/ruomini/jdk-17.0.7
ruomini@ruomini-XPS-13-9370:~$ java -version
openjdk version "11.0.18" 2023-01-17
OpenJDK Runtime Environment (build 11.0.18+10-post-Ubuntu-0ubuntu122.04)
OpenJDK 64-Bit Server VM (build 11.0.18+10-post-Ubuntu-0ubuntu122.04, mixed mode, sharing)

尝试解决的过程 #

尝试通过update-alternatives切换Java版本，但发现已放置在/usr/lib/jvm目录下的Java 17并未出现在备选列表中：

ruomini@ruomini-XPS-13-9370:~/android-studio/bin$ update-alternatives --list java

/usr/lib/jvm/java-11-openjdk-amd64/bin/java
/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
ruomini@ruomini-XPS-13-9370:~/android-studio/bin$ ls -al /usr/lib/jvm
total 40
drwxr-xr-x   5 root root  4096 May 15 09:31 .
drwxr-xr-x 159 root root 16384 Feb 23 18:18 ..
lrwxrwxrwx   1 root root    10 May 15 09:16 default-java -> jdk-17.0.7
lrwxrwxrwx   1 root root    21 Jul 18  2019 java-1.11.0-openjdk-amd64 -> java-11-openjdk-amd64
-rw-r--r--   1 root root  2047 Jan 20 10:07 .java-1.11.0-openjdk-amd64.jinfo
drwxr-xr-x   9 root root  4096 Mar  1 06:01 java-11-openjdk-amd64
lrwxrwxrwx   1 root root    20 Mar 12  2018 java-1.8.0-openjdk-amd64 -> java-8-openjdk-amd64
-rw-r--r--   1 root root  2764 Jan 24 20:02 .java-1.8.0-openjdk-amd64.jinfo
drwxr-xr-x   5 root root  4096 Jun 24  2016 java-8-openjdk-amd64
drwxr-xr-x   9 root root  4096 May 15 09:09 jdk-17.0.7

最终解决方案 #

重要更新：经排查，问题根源是Java SDK未正确安装。完成Java 17 SDK的正确安装后，版本显示异常的问题得以解决。

内容的提问来源于stack exchange，提问作者FractalBob