ubuntu 系统下解决普通用户使用 source /etc/profile 下才能加载java 命令

解决 source /etc/profile 下才能使用java 命令

步骤:

• 在linux系统正常的部署jdk，通过解压压缩包的方式，压缩包，解压完成之后，配置jdk的环境变量

nvidia@tegra-ubuntu:~$ cat /etc/profile
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "$PS1" ]; then
  if [ "$BASH" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi
下面内容是jdk的环境变量

export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_231
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

• 如上配置后，我们输入java。并不能得到java相关提示，。如下

nvidia@tegra-ubuntu:~$ cat /etc/profile
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "$PS1" ]; then
  if [ "$BASH" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_231
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

如下是错误的
nvidia@tegra-ubuntu:~$ java 
-bash: java: command not found
nvidia@tegra-ubuntu:~$ java 
-bash: java: command not found

• 如何解决呢？编辑另外的一个文件，将环境变量加到最后面，就可以不用source /etc/profile, 就可以直接使用了

nvidia@tegra-ubuntu:~$ vim .bashrc 
nvidia@tegra-ubuntu:~$ vim .bashrc 

内容如下：
Xshell 6 (Build 0121)
Copyright (c) 2002 NetSarang Computer, Inc. All rights reserved.

Type `help' to learn how to use Xshell prompt.
[C:\~]$ 

Connecting to 192.168.31.236:22...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.

Welcome to Ubuntu 16.04 LTS (GNU/Linux 4.4.38-tegra aarch64)

 * Documentation:  https://help.ubuntu.com/

686 packages can be updated.
414 updates are security updates.

New release '18.04.3 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

Last login: Tue Nov 19 07:26:12 2019 from 192.168.31.139
nvidia@tegra-ubuntu:~$ ls
Desktop    examples.desktop  libvisionworks-repo_1.6.0.500n_arm64.deb       Music                    Pictures              sht_workdir           Templates       wangman
Documents  jetson_clocks.sh  libvisionworks-sfm-repo_0.90.3_arm64.deb       NVIDIA_CUDA-9.0_Samples  Public                tegra_multimedia_api  test_GFSDetect  weston.ini
Downloads  jy_workdir        libvisionworks-tracking-repo_0.88.1_arm64.deb  OpenCV                   report_ip_to_host.sh  tegrastats            Videos
nvidia@tegra-ubuntu:~$ cat /etc/profile
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "$PS1" ]; then
  if [ "$BASH" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_231
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH


nvidia@tegra-ubuntu:~$ java 
-bash: java: command not found
nvidia@tegra-ubuntu:~$ java 
-bash: java: command not found
nvidia@tegra-ubuntu:~$ vim .bashrc 
nvidia@tegra-ubuntu:~$ vim .bashrc 
nvidia@tegra-ubuntu:~$ cat /etc/profile
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "$PS1" ]; then
  if [ "$BASH" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi

将如下的内容加入到文件中即可
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_231
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

如上就可以解决这个问题了