尝试“ apt install openjdk-8-jre-headless”和“ apt install openjdk-8-jdk”后，java不可用

Question

我尝试安装支持Java 11的最新稳定Jenkins版本。因此，在安装Java 11（JDK）之后，我从Jenkins收到了一个错误消息，即发现了错误的Java版本。

因此，卸载了Java 11并尝试安装Java8。在安装Java 8时，反复出现Jenkins消息“找到了错误的Java版本”。 因此，我完全删除了Java 11（JDK）和Java 8（JDK），并确保Java 11和Java 8的/ usr / bin和/ usr / lib / jvm中都没有文件夹。说安装了JDK 8，但无法在我的系统中找到任何Java版本。 为什么？

我尝试了sudo apt install openjdk-8-jre-headless和sudo apt install openjdk-8-jdk但在/ usr / bin中没有java并且/ usr / lib / jvm中有java8jdk但在bin中没有java夹。 请参见下面的命令和控制台输出。

sudo apt install openjdk-8-jdk
Reading package lists... Done
Building dependency tree 
Reading state information... Done
The following packages were automatically installed and are no longer required:
daemon net-tools
Use 'sudo apt autoremove' to remove them.
Suggested packages: openjdk-8-demo openjdk-8-source visualvm
The following NEW packages will be installed
openjdk-8-jdk
0 upgraded, 1 newly installed, 0 to remove and 14 not upgraded.
Need to get 0 B/1,435 kB of archives. After this operation, 1,538 kB of additional disk space will be used.
Selecting previously unselected package openjdk-8-jdk:amd64. (Reading database ... 168837 files and directories currently installed.)
Preparing to unpack .../openjdk-8-jdk_8u191-b12-2ubuntu0.18.04.1_amd64.deb ...
Unpacking openjdk-8-jdk:amd64 (8u191-b12-2ubuntu0.18.04.1) ...
Setting up openjdk-8-jdk:amd64 (8u191-b12-2ubuntu0.18.04.1) ..
update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/bin/appletviewer to provide /usr/bin/appletviewer (appletviewer) in auto mode
update-alternatives: using /usr/lib/jvm/java-8-openjdk-amd64/bin/jconsole to provide /usr/bin/jconsole (jconsole) in auto mode

当我尝试openjdk-jre-headless时，我得到了以下内容

sudo apt install openjdk-8-jre-headless
Reading package lists... Done
Building dependency tree Reading state information... Done
openjdk-8-jre-headless is already the newest version (8u191-b12-2ubuntu0.18.04.1).
The following packages were automatically installed and are no longer required:
daemon libice-dev libpthread-stubs0-dev libsm-dev libx11-dev libx11-doc libxau-dev libxcb1-dev libxdmcp-dev libxt-dev net-tools openjdk-8-jdk-headless x11proto-core-dev x11proto-dev xorg-sgml-doctools xtrans-dev 
Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 14 not upgraded

还是没用。 我找不到Java。 which java什么都不返回。 java -version返回以下内容。... Command 'java' not found, but can be installed with: sudo apt install default-jre sudo apt install openjdk-11-jre-headless sudo apt install openjdk-8-jre-headless

有人可以帮我解决这个问题吗？ 如何正确安装Java？ 删除/卸载Jenkins之后，我也尝试安装Java，但是没有用。 我先前安装的jenkins是否阻止任何Java安装？

Answer 1

您是否尝试过将Java添加到环境变量中？

1. 检查您安装的Java版本并选择所需的版本sudo update-alternatives --config java

2. 将Java路径导出为环境变量export PATH=$PATH:/usr/java/jrex.x.x_xxx/bin/

3. 将此行添加到家庭目录中的.bashrc文件中。 打开bash时，这将更新您的环境变量

也许这个答案可以帮助您。