linux 查看java的安裝路徑

在linux下,如何找java的安裝路徑：

[root@VM_0_14_centos share]# whereis java
java: /usr/bin/java /usr/lib/java /etc/java /usr/share/java /usr/share/man/man1/java.1.gz
[root@VM_0_14_centos share]# ls -lrt /usr/bin/java
lrwxrwxrwx 1 root root 22 Jun  2 15:56 /usr/bin/java -> /etc/alternatives/java
[root@VM_0_14_centos share]# ls -lrt /etc/alternatives/java
lrwxrwxrwx 1 root root 73 Jun  2 15:56 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java

jdk配置環境變量：

vim /etc/profile

在文件末尾添加

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

使配置生效 

source /etc/profile

查看JAVA_HOME環境變量

[root@VM_0_14_centos share]# echo $JAVA_HOME
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java