Java 安装指引

Ubuntu

JAVA_HOME

定义在 /etc/environment 中，比如：

JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64"

PPA 

add-apt-repository ppa:linuxuprising/java

sdkman

手动安装的 Oracle JDK 可用 sdkman 注册后配置为默认 JDK：

# SDKman 依赖 zip 命令行
apt install zip
curl -s "https://get.sdkman.io" | bash

sdk list java

sdk install java 11.0.11.hs-adpt # 
sdk install java 8.0.292.j9-adpt # IBM JDK

sdk install java 11.0.13-ms

# Link local version
sdk install java 16.0.2-oracle /usr/lib/jvm/jdk-16.0.2
sdk install java 11.0.12-oracle /usr/lib/jvm/jdk-11.0.12
sdk default java 11.0.12-oracle
sdk use java 11.0.12-oracle

JDK 版本切换

# 查看已安装 JDK
/usr/libexec/java_home -V

macOS 可以配置以下别名快速设置 JAVA_HOME：

alias j15="export JAVA_HOME=`/usr/libexec/java_home -v 15`"
alias j11="export JAVA_HOME=`/usr/libexec/java_home -v 11`"
alias j8="export JAVA_HOME=`/usr/libexec/java_home -v 1.8`"

Ubuntu

sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-16.0.2/bin/java 1000
sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-16.0.2/bin/javac 1000
sudo update-alternatives --install /usr/bin/javadoc javadoc /usr/lib/jvm/jdk-16.0.2/bin/javadoc 1000
sudo update-alternatives --install /usr/bin/javap javap /usr/lib/jvm/jdk-16.0.2/bin/javap 1000
sudo update-alternatives --config java

JRE 添加 CA

sudo keytool -import -alias CERTIFICATE_ALIAS -keystore /usr/lib/jvm/java-7-openjdk-amd64/jre/lib/security/cacerts -file CERTIFICATE.crt

参考