ubuntu命令安装jdk

1.ubuntu使用的是openjdk，所以我们需要先找到合适的jdk版本。在命令行中输入命令：

apt-cache search openjdk

返回结果列表(因个人电脑而有所不同)：

default-jdk-doc - Standard Java or Java compatible Development Kit (documentation) 
…(省略部分显示结果) 
openjdk-6-source - OpenJDK Development Kit (JDK) source files 
openjdk-7-jre-dcevm - Alternative VM for OpenJDK 7 with enhanced class redefinition 
openjdk-7-jre-lib - OpenJDK Java runtime (architecture independent libraries) 
openjdk-7-jre-zero - Alternative JVM for OpenJDK, using Zero/Shark 
openjdk-8-dbg - Java runtime based on OpenJDK (debugging symbols) 
openjdk-8-demo - Java runtime based on OpenJDK (demos and examples) 
openjdk-8-doc - OpenJDK Development Kit (JDK) documentation 
openjdk-8-jdk - OpenJDK Development Kit (JDK) 
openjdk-8-jre - OpenJDK Java runtime, using Hotspot JIT 
openjdk-8-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless) 
openjdk-8-jre-jamvm - Alternative JVM for OpenJDK, using JamVM 
openjdk-8-jre-zero - Alternative JVM for OpenJDK, using Zero/Shark 
openjdk-8-source - OpenJDK Development Kit (JDK) source files 
uwsgi-app-integration-plugins - plugins for integration of uWSGI and application 
uwsgi-plugin-jvm-openjdk-7 - Java plugin for uWSGI (OpenJDK 7)

2.从搜索的列表里找到我们需要安装的jdk版本，如上面标黑的 

openjdk-8-jdk - OpenJDK Development Kit (JDK)

3.输入安装命令，进行安装：

apt-get install openjdk-8-jdk

等待命令行显示“done”，即安装成功过。

4.查看安装结果。输入命令：

java -version

显示结果如下：

openjdk version "1.8.0_222"
OpenJDK Runtime Environment (build 1.8.0_222-8u222-b10-1~deb9u1-b10)
OpenJDK Client VM (build 25.222-b10, mixed mode)

则说明安装成功。