用java 8 API替换两个嵌套的for循环

我有以下片段，我想知道是否以及如何用Streams / Java 8 API替换它

for (State state : states) { for (City city : cities) { if (state.containsPoint(city.getLocation())) { System.out.printf("%30s is part of %-30s\n", city.getName(), state.getName()); } } } 

Answer 1

会是这样的：

 // first loop states.forEach(state -> { // second loop for filtered elements cities.stream().filter(city -> state.containsPoint(city.getLocation())).forEach(city -> { System.out.printf("%30s is part of %-30s\n", city.getName(), state.getName()); }); });