Ask HN: Why is “advice in Effective Java considered inappropriate for Android”?

13 points by amolgupta 9 years ago | 7 comments

I came across this statement on Dagger's documentation at [http://google.github.io/dagger/android.html]. Also there is a discussion on reddit [https://reddit.com/r/androiddev/comments/4smncj/is_this_true/] but it does not cover much.

ng12 9 years ago |

Android uses Dalvik/ART, which is an alternative to the JVM that has an entirely different set of optimizations for mobile. The most important one is that object creation is significantly more expensive -- if your code is allocating lots of objects it will significantly impact performance. This is why Android has the whole Recycler paradigm. My gut reaction is that Effective Java recommends a lot of heavy-OO practices which may impact Android performance.

jpetitto 9 years ago |

I would say most of it IS appropriate. A lot of the advice is good for Java development in general, regardless of platform. Enums are one area that is hotly debated in the Android community, but there is no consensus on it.

Generally, I would say follow the advice in Effective Java, but be aware of some potential performance issues and how you can avoid/fix them if need be.

Edit: I noticed there is a chapter on serialization. This can be ignored by Android developers in favor of Parcelable.

mamon 9 years ago |

Simple answer: because Android is not Java. It's a compeletely different platform, that just happens to use a programming language similar to Java to write programs for it's virtual machine.

Something1234 9 years ago | |

It's java, but it has a different standard library and different api.

edblarney 9 years ago | |

It is de-facto Java.

It uses java syntax, java libraries.

To say it is 'not Java' is borderline disingenuous.

Technically, there are differences which are real, and it's very fair to point them out.

But - Java syntax + java.lang/java.io/java.net/java.reflect/java.util + a vm, can use a JAVA IDE and java build chain, use 3rd party java libs ...

=> it's java.

hhandoko 9 years ago | | |

I don't think this analogy is accurate.

It uses Java as the development language, but it has different runtime, not simply a different platform / target, and thus different rules apply.

In regards with the Java libraries, I think this is pretty much already covered in the Google vs Oracle case. Android provides a system implementation that matches the interface, thus these code can work almost seamlessly. Similar to how .NET and Mono works.