import java.util.HashMap; import java.util.Map; public class Test { private Map<Class<?>, Object> contents = new HashMap<Class<?>, Object>(); private <T> T getContent(Class<T> type){ return type.cast(contents.get(type)); } public static void main(String[] args) { Test test = new Test(); test.contents.put(String.class, "メモですよ"); String newMemo = test.getContent(String.class); System.out.println(new
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