zbb20181227 map,LinkedHashMap按順序存放key,MultiValueMap 一個key對多個value

MultiValueMap 一個key對多個value 需要引入pom

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>4.2</version>
</dependency>

MultiValueMap multiValueMap = new MultiValueMap();
multiValueMap.put("123", "String");
multiValueMap.put("123", "String");
multiValueMap.put("abc", "String");
multiValueMap.put("abcde", "String");
multiValueMap.put("1234", "String");
multiValueMap.put("abcd", "String");
multiValueMap.put("1234", "String");
System.out.println(multiValueMap.getCollection("123"));
System.out.println(multiValueMap.keySet());

LinkedHashMap按順序存放key,

Map<String, String> multiValueMap = new LinkedHashMap<String, String>();
multiValueMap.put("123", "String");
multiValueMap.put("123", "String");
multiValueMap.put("abc", "String");
multiValueMap.put("abcde", "String");
multiValueMap.put("1234", "String");
multiValueMap.put("abcd", "String");
multiValueMap.put("1234", "String");
System.out.println(multiValueMap.keySet());