方法多种多样，其实大差不差~

1. 通过 键值集（entrySet）遍历

System.out.println("Ⅰ、使用 entrySet() 方法遍历：");
for (Map.Entry<String, String> entry : map.entrySet()) {String key = entry.getKey();String value = entry.getValue();System.out.println("Key: " + key + ", Value: " + value);
}

2. 通过 键集（keySet）遍历

System.out.println("----------------------------");
System.out.println("Ⅱ、使用 keySet() 方法遍历：");
for (String key : map.keySet()) {String value = map.get(key);System.out.println("Key: " + key + ", Value: " + value);
}

3. 通过 值集（values），只能获取到值，不能获取到键

System.out.println("----------------------------");
System.out.println("Ⅲ、也可以使用 values() 方法遍历所有值，但这种方式无法获取对应的键：");
for (String value : map.values()) {System.out.println("Value: " + value);
}

4. EntrySet迭代器的遍历

System.out.println("----------------------------");
System.out.println("EntrySet迭代器的遍历，在IDEA中会推荐替换while为增强for");
Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {Map.Entry<String, String> entry = iterator.next();System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue());
}

5. KeySet迭代器的遍历

System.out.println("----------------------------");
System.out.println("Ⅴ、KeySet迭代器的遍历，在IDEA中会推荐替换while为增强for");
Iterator<String> iterator2 = map.keySet().iterator();
while (iterator2.hasNext()) {String key = iterator2.next();System.out.println("Key: " + key + ", Value: " + map.get(key));
}

6. StreamAPI

System.out.println("----------------------------");
System.out.println("Ⅵ、StreamAPI，IDEA会推荐替换stream().forEach()为map.entrySet().forEach()");
System.out.println("IDEA会推荐替换map.entrySet().forEach()为map.forEach()，见最后一个");

7. EntrySet的forEach()

System.out.println("----------------------------");
System.out.println("Ⅶ、EntrySet的forEach()");
map.entrySet().forEach(entry -> System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue()));

8. Java 8引入的Map接口中的forEach()方法

System.out.println("----------------------------");
System.out.println("Ⅷ、Java 8引入的Map接口中的forEach()方法");
System.out.println("简介且易阅读");
map.forEach((key, value) -> System.out.println("Key: " + key + ", Value: " + value));

测试代码

public class Main {public static void main(String[] args) {Map<String, String> map = new HashMap<>();map.put("1", "111");map.put("2", "222");map.put("3", "test");System.out.println("Ⅰ、使用 entrySet() 方法遍历：");for (Map.Entry<String, String> entry : map.entrySet()) {String key = entry.getKey();String value = entry.getValue();System.out.println("Key: " + key + ", Value: " + value);}System.out.println("----------------------------");System.out.println("Ⅱ、使用 keySet() 方法遍历：");for (String key : map.keySet()) {String value = map.get(key);System.out.println("Key: " + key + ", Value: " + value);}System.out.println("----------------------------");System.out.println("Ⅲ、也可以使用 values() 方法遍历所有值，但这种方式无法获取对应的键：");for (String value : map.values()) {System.out.println("Value: " + value);}System.out.println("----------------------------");System.out.println("EntrySet迭代器的遍历，在IDEA中会推荐替换while为增强for");Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();while (iterator.hasNext()) {Map.Entry<String, String> entry = iterator.next();System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue());}System.out.println("----------------------------");System.out.println("KeySet迭代器的遍历，在IDEA中会推荐替换while为增强for");Iterator<String> iterator2 = map.keySet().iterator();while (iterator2.hasNext()) {String key = iterator2.next();System.out.println("Key: " + key + ", Value: " + map.get(key));}System.out.println("----------------------------");System.out.println("values迭代器的遍历，在IDEA中会推荐替换while为增强for");Iterator<String> iterator3 = map.values().iterator();while (iterator3.hasNext()) {String value = iterator3.next();System.out.println("Value: " + value);}System.out.println("----------------------------");System.out.println("StreamAPI，IDEA会推荐替换stream().forEach()为map.entrySet().forEach()，见倒二");System.out.println("IDEA会推荐替换map.entrySet().forEach()为map.forEach()，见最后一个");map.entrySet().stream().forEach(entry -> System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue()));System.out.println("----------------------------");System.out.println("EntrySet的forEach()");map.entrySet().forEach(entry -> System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue()));System.out.println("----------------------------");System.out.println("Java 8引入的Map接口中的forEach()方法");System.out.println("简介且易阅读");map.forEach((key, value) -> System.out.println("Key: " + key + ", Value: " + value));}}