java
复制代码
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+lambda
dataMap.forEach((k,v)-> System.out.println(k+"->"+v));
// 2. keySet+foreach
for (String key: dataMap.keySet()){
System.out.println(key+"->"+dataMap.get(key));
}
// 3. entry+stream
dataMap.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.EntrySet
for (Map.Entry<String,String> item: dataMap.entrySet()) {
System.out.println(item.getKey()+"->"+item.getValue());
}
// 6.迭代器+Map.Entry
Iterator<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));
}
}
}