org.apache.xbean.asm5.commons.package.html Maven / Gradle / Ivy
Provides some useful class and method adapters. The preferred way of using
these adapters is by chaining them together and to custom adapters (instead of
inheriting from them). Indeed this approach provides more combination
possibilities than inheritance. For instance, suppose you want to implement an
adapter MyAdapter than needs sorted local variables and intermediate stack map
frame values taking into account the local variables sort. By using inheritance,
this would require MyAdapter to extend AnalyzerAdapter, itself extending
LocalVariablesSorter. But AnalyzerAdapter is not a subclass of
LocalVariablesSorter, so this is not possible. On the contrary, by using
delegation, you can make LocalVariablesSorter delegate to AnalyzerAdapter,
itself delegating to MyAdapter. In this case AnalyzerAdapter computes
intermediate frames based on the output of LocalVariablesSorter, and MyAdapter
can add new locals by calling the newLocal method on LocalVariablesSorter, and
can get the stack map frame state before each instruction by reading the locals
and stack fields in AnalyzerAdapter (this requires references from MyAdapter
back to LocalVariablesSorter and AnalyzerAdapter).