17. More APIs

This chapter gathers a couple of more APIs you can use in your app. First we have the math API that gets used for mathematical calculations. For date and time handling, including transformations between different time representations, and parsing and formatting dates and times, we describe the date and time API. For input and output, which for Android boils down to file handling, we give an overview of the input and output API. For dynamically acquiring class member information the reflection API gets used; this is not a prominent part of object orientation but can help under some circumstances, so we include a treatise on reflection. A very powerful means to investigate and manipulate patterns inside strings is evident if we look at regular expressions, so we finish the chapter with a survey of regular expression constructs.