Centos7安装Oracle JDK8

Centos7自带了OpenJDK1.8，我们不想要。想用JDK8，怎么办：

• Download JDK1.8 rpm:
  wget http://download.oracle.com/otn-pub/java/jdk/8u101-b13/jdk-8u101-linux-x64.rpm
• Install JDK1.8:
  sudo rpm -ivh jdk-8u101-linux-x64.rpm
• Switch from Open JDK to Oracle JDK:
  sudo alternatives --config java* (Select the item for jdk1.8) *
• Check it:

which java
java -version
which javac
javac -version