用yum list java-1.8*搜出来一堆JDK
Failed to set locale, defaulting to C
Loaded plugins: langpacks
Available Packages
java-1.8.0-openjdk.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-accessibility.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-accessibility-debug.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-debug.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-demo.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-demo-debug.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-devel.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-devel-debug.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-headless.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-headless-debug.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-javadoc.noarch 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-javadoc-debug.noarch 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-src.x86_64 1:1.8.0.91-0.b14.el7_2 updates
java-1.8.0-openjdk-src-debug.x86_64 1:1.8.0.91-0.b14.el7_2
要选哪一个呢?第一个才是JDK，其他的都不是。
最好装Oracle的jdk，open jdk可能会有些问题。