I was writing an Android app for Android SDK 2.3.3 but then I was asked to test it on a device running Android 2.2.1. So I set my target to 8 instead of 10. But then java.util.concurrent.TimeUnit only had the Java 1.5 feature set instead of the Java 1.6/1.7 feature set of java.util.concurrent.TimeUnit. So I put the openjdk 6 implementation of TimeUnit into my package for my Android app and everything works fine.
Does anyone know where I can get some documentation that gives me a chart that tells me, for example, that when using the official SDK, Android 2.2 has to be coded using Java 1.5 keywords/syntax/APIs, Android 2.3.3 can be coded using Java 1.6 keywords/syntax/APIs, etc...?
You are trying to look at Android as a subset of Java which it is not. They are completely separated. Even though Android comes from Java, it as departed from it quite a bit and there is no correlation 'version-wise' anymore between the two.
What you can look at is the Android documentation. For every instruction/command/method/properties, at the top right you'll find the api level at which you are able to access said property.
Clicking on the api level will take you to a page which contains a table that translates api level to Android versions.
The easy way to find out if you are allowed to use a property is using eclipse and doing what you just did : Change the target api level. Then any call to methods or properties that are not available to you will produce fatal errors.