[tt@vddd conf]$ java -versionopenjdk version "1.8.0_65"OpenJDK Runtime Environment (build 1.8.0_65-b17)OpenJDK 64-Bit Server VM (build 25.65-b01, mixed mode)[tt@vddd conf]$ echo $JAVA_HOME[tt@vddd conf]$ echo $PATH/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/app/tt/.local/bin:/app/tt/bin[tt@vddd conf]$ whereis javajava: /usr/bin/java /usr/lib/java /etc/java /usr/share/java /usr/share/man/man1/java.1.gz[tt@vddd conf]$ which java/usr/bin/java[tt@vddd conf]$ cd /usr/bin/java-bash: cd: /usr/bin/java: Not a directory[tt@vddd conf]$ ls -lrt /usr/bin/javalrwxrwxrwx. 1 root root 22 Oct 18 11:19 /usr/bin/java -> /etc/alternatives/java[tt@vddd conf]$  ls -lrt /etc/alternatives/javalrwxrwxrwx. 1 root root 70 Oct 18 11:19 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64/jre/bin/java[tt@vddd conf]$ cd /usr/lib/jvm[tt@vddd jvm]$ lsjava-1.7.0-openjdk-1.7.0.91-2.6.2.3.el7.x86_64  jre-1.7.0                                      jre-1.8.0                                    jre-openjdkjava-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64    jre-1.7.0-openjdk                              jre-1.8.0-openjdkjre                                             jre-1.7.0-openjdk-1.7.0.91-2.6.2.3.el7.x86_64  jre-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64[tt@vddd jvm]$