七种遍历Map的方法

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;public class Wan {public static void main(String[] args) {Map<String,String> dataMap = new HashMap<>();dataMap.put("A","Abb");dataMap.put("B","Bcc");dataMap.put("C","Cdd");// 1. forEach+lambdadataMap.forEach((k,v)-> System.out.println(k+"->"+v));// 2. keySet+foreachfor (String key: dataMap.keySet()){System.out.println(key+"->"+dataMap.get(key));}// 3. entry+streamdataMap.entrySet().stream().forEach(entry ->System.out.println(entry.getKey()+"->"+entry.getValue()));// 4. stream并行处理dataMap.entrySet().stream().parallel().forEach(entry ->System.out.println(entry.getKey()+"->"+entry.getValue()));// 5. foreach Map.EntrySetfor (Map.Entry<String,String> item: dataMap.entrySet()) {System.out.println(item.getKey()+"->"+item.getValue());}// 6.迭代器+Map.EntryIterator<Map.Entry<String,String>> item2 = dataMap.entrySet().iterator();while (item2.hasNext()){Map.Entry<String,String> next = item2.next();System.out.println(next.getKey()+"->"+next.getValue());}// 7. keyset+迭代器Iterator<String> item3 = dataMap.keySet().iterator();while (item3.hasNext()){String key = item3.next();System.out.println(key+"->"+dataMap.get(key));}}
}