Home|About|Gaming cabinet|Archives|How it works|Starter sites

GeezerVison is showing javaevolved.dev — Generics — java.evolved

Home / Topics / Generics

🏷 Generics 2 patterns

Topic: Generics

All Java patterns related to Generics — java.evolved

Diamond with anonymous classes

Old Map<String, List<String>> map = new HashMap<String, List<String>>(); // anonymous class: no diamond Predicate<String> p = new Predicate<String>() { public boolean test(String s) {..} };

Modern Map<String, List<String>> map = new HashMap<>(); // Java 9: diamond with anonymous classes Predicate<String> p = new Predicate<>() { public boolean test(String s) {..} };

hover to see modern →

JDK 9+ learn more →

Raw collections to generic types

Old List names = new ArrayList(); names.add("Duke"); String name = (String) names.get(0);

Modern List<String> names = new ArrayList(); names.add("Duke"); String name = names.get(0);

hover to see modern →

JDK 5+ learn more →