背景：
我用MacBookPro开发java应用程序，效果很好。而在我将MacOS从10.x升级到最新版本之后 Big Sur , mvn clean package 引发以下异常：
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project dq-common: Compilation failure
[ERROR] Unable to locate the Javac Compiler in:
[ERROR] /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/../lib/tools.jar
[ERROR] Please ensure you are using JDK 1.4 or above and
[ERROR] not a JRE (the com.sun.tools.javac.Main class is required).
[ERROR] In most cases you can change the location of your Java
[ERROR] installation by setting the JAVA_HOME environment variable.
``` `java -version` :jingxingdeMacBook-Pro:~ kevin$ java -version
java version "1.8.0_271"
Java(TM) SE Runtime Environment (build 1.8.0_271-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.271-b09, mixed mode)
jingxingdeMacBook-Pro:dt-center-valid-4.0 kevin$
``` which java 升级后已更改：
之前：
ingxingdeMacBook-Pro:bin kevin$ which java
/Library/Java/JavaVirtualMachines/jdk1.8.0_251.jdk/Contents/Home/bin/java现在：
jingxingdeMacBook-Pro:~ kevin$ which java
/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java
``` `cat ~/.bash_profile` :jingxingdeMacBook-Pro:~ kevin$ cat ~/.bash_profile
export M2_HOME=/usr/local/apache-maven-3.6.3
Mac OSX 10.5 or later version need this configure
export JAVA_HOME=$(/usr/libexec/java_home)
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_251.jdk/Contents/Home
export MySQL_HOME=/usr/local/mysql
export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar:.
export HADOOP_HOME=/Users/kevin/Desktop/Developments/Software/hadoop-3.3.0
PATH=$M2_HOME/bin:$JAVA_HOME/bin:$MySQL_HOME/bin:$HADOOP_HOME/bin:$PATH:.
export PATH
问题：
为什么？ `which java` 我升级mac操作系统后，输出发生了变化，如何修复它。
2条答案
按热度按时间7z5jn7bk1#
原因：在
~/.bash_profile,JAVA_HOME= $(/usr/libexec/java_home)，升级后，$（/usr/libexec/java\u home）链接到/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java在我的磁盘中不存在，所以jdk丢失了。解决方案：在中删除jdk
/Library/Java/JavaVirtualMachines重新安装jdk8，然后设置JAVA_HOME作为：/Library/Java/JavaVirtualMachines/jdk1.8.0_271.jdk/Contents/Home而不是软链接和source ~/.bash_profile让它工作。我的完整设置：
现在，jdk工作了，在macos升级之后，它确实更新了
$(/usr/libexec/java_home)并且链接到一个不存在的链接，所以我认为您不需要删除您的jdk，只需更新env变量并重新打开终端来检查jdk是否正确重置。i1icjdpr2#
找到你的jdk位置（我的是
/Library/Java/JavaVirtualMachines/jdk1.8.0_162.jdk/Contents/Home).在终端
vim ~/.bash_profile（分别。以您习惯的任何方式编辑文件）添加一行导出jdk位置（在我的例子中是
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_162.jdk/Contents/Home)在终端
source ~/.bash_profile在终端echo $JAVA_HOME确保环境变量设置正确