pi@raspberrypi:~ $ sudo update-alternatives --query java
Name: java
Link: /usr/bin/java
Slaves:
 java.1.gz /usr/share/man/man1/java.1.gz
Status: auto
Best: /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/jre/bin/java
Value: /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/jre/bin/java

Alternative: /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/jre/bin/java
Priority: 318
Slaves:
 java.1.gz /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/man/man1/java.1.gz