download and install the jdk1.8 on ubuntu14.4

1 check the version

uname -a

#62~14.04.1-Ubuntu SMP Fri Mar 11 11:03:15 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

2 download JDK 1.8

go to the blow url to download the java with 64bit of linux
http://www.androiddevtools.cn/
3 extract jdk1.8.0 to /usr/lib/jvm

sudo tar zxvf jdk-8u77-linux-x64.tar.gz -C /usr/lib/jvm

4 export the path and JAVA_HOME

4.1 sudo vim /etc/profile

export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_77

export CLASSPATH=".:$JAVA_HOME/lib:$CLASSPATH"

export PATH="$JAVA_HOME/bin:${ANDROID_NDK}:$PATH"

4.2 . /etc/profile

5 set the java, javac link in usr/bin/

sudo update-alternatives --install /usr/bin/javac javac/usr/lib/jvm/jdk1.8.0_77/bin/javac 300

sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_77/bin/java 300

6 select the default java version

sudo update-alternatives --config java

7 verify it

javac -version