1. Take 1.6 as an example to find the corresponding version
$ yum --showduplicate list java* |grep 1.6 java-1.6.0-openjdk.x86_64 1:1.6.0.41-1.13.13.1.el6_8 base java-1.6.0-openjdk-demo.x86_64 1:1.6.0.41-1.13.13.1.el6_8 base java-1.6.0-openjdk-devel.x86_64 1:1.6.0.41-1.13.13.1.el6_8 base java-1.6.0-openjdk-javadoc.x86_64 1:1.6.0.41-1.13.13.1.el6_8 base java-1.6.0-openjdk-src.x86_64 1:1.6.0.41-1.13.13.1.el6_8 base
2. Install the corresponding version
$ yum install java-1.6.0-openjdk.x86_64