Ubuntu under JDK installation (update old version of Java)

1.sudo apt-get install openjdk-8-jre openjdk-8-jdk

2. The default is installed under the path of/USR/LIB/JVM/JAVA-7-OPENJDK-AMD64

3. Configuring Environment variables

Vim ~/.BASHRC

Export java_home =/usr/lib/jvm/openjdk-8-jdk-i386 (mine is 32 bits)

SOURCE ~/.BASHRC

4. Test that the Java version is configured correctly

Java-version

$JAVA _home/bin/java-version

Inconsistent results can be performed with the following code for version switching

sudo update-alternatives--config java

sudo update-alternatives--config javac

At this time to execute, found the version has been!!
Congratulations, UPDATE success!!!

Ubuntu under JDK installation (update old version of Java)