In our third Fragment installment, we introduce Josh's second Item: Consider a builder when faced with many constructor parameters.

Stay tuned for more items from our "Effective Java for Android developers" Fragment series.

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Show Notes * Effective Java (2nd Edition) - Joshua Bloch

Consider a builder when faced with many constructor parameters Patterns available for constructing object with parameters: * Telescoping Constructor Pattern - Provideconstructor with only required parameters, another with a single optional param, a third with 2 optional params... and so on. + Advantage: Works well for small number of parameters + Disadvantage: Does NOT scale well * JavaBeans Pattern - Callparameterless constructor to create the object; then call setter methods to set required parameter and each optional param of interest. + Advantage: Scales well, easy (but wordy) to read resulting code + Disadvantage: Allows inconsistency (if all required params not called); impossible to make classes immutable if using this pattern. * Builder pattern - winner! + Advantage: Simulates named optional parameters; allows immutable objects to be constructed; flexible + Disadvantage: more ceremony to actually construct the Builder Class and finally use.

Example usage from Android source: * AlertDialog Builder [androidxref.com]

Tip: * Use IntelliJ to generate your Builders easily

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