Question

我正在尝试将json数据放入HashMap中，其中可能包含很多重复的键。例如：

    {
    "member Detial": {
        "firstname": "jhon",
        "lastName": "wick",
        "Address": "New York",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "Password": "newyorkcitizen",
        "confirm password": "newyorkcitizen",
        "NationalProviderIdentifier": "Apollo",
        "PartyID": "1"
    },


    "Physician": {
        "firstname": "jhon",
        "lastName": "wick",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "NationalProviderIdentifier": "Apollo",
        "PartyID": "1"

    },

    "PhysicianGroup": {
        "Address": "New York",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "NationalProviderIdentifier": "Apollo",
        "Hospital name": "Apollo",
        "Tax ID": "12345",
        "PartyID": "1"

    },
            "Physician": {
        "Address": "New York",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "NationalProviderIdentifier": "Apollo",
        "Hospital name": "Apollo",
        "Tax ID": "12345",
        "PartyID": "1"

    },
}

上面的json文件中的

被认为是“成员详细信息”，而括号内的数据被视为值。但是这里的问题是上面的json示例中可能有重复的键，例如“ Physician”。

我想将第二个“医师”的值添加到第一个“医师”而不覆盖其值，并删除重复键。例如：`

   {

"member Detial": {
    "firstname": "jhon",
    "lastName": "wick",
    "Address": "New York",
    "Email": "jhonwick@boogiman.com",
    "Fax Number": "09876543",
    "Contact Number": "9876543210",
    "Password": "newyorkcitizen",
    "confirm password": "newyorkcitizen",
    "NationalProviderIdentifier": "Apollo",
    "PartyID": "1"
},


"Physician": [{
        "firstname": "jhon",
        "lastName": "wick",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "NationalProviderIdentifier": "Apollo",
        "PartyID": "1"
    },
    {
        "Address": "New York",
        "Email": "jhonwick@boogiman.com",
        "Fax Number": "09876543",
        "Contact Number": "9876543210",
        "NationalProviderIdentifier": "Apollo",
        "Hospital name": "Apollo",
        "Tax ID": "12345",
        "PartyID": "1"
    }
],
"PhycianGroup": {
    "Address": "New York",
    "Email": "jhonwick@boogiman.com",
    "Fax Number": "09876543",
    "Contact Number": "9876543210",
    "NationalProviderIdentifier": "Apollo",
    "Hospital name": "Apollo",
    "Tax ID": "12345",
    "PartyID": "1"

  }
}

`

Answer 1

Guava与Multimap<K, V>一起提供。这正是您要寻找的：

将键映射到值的集合，类似于Map，但其中每个键可能与多个值关联。您可以将多图的内容可视化为从键到值的非空集合的映射：


a→1，2

b→3


...或作为键值对的单个“扁平化”集合：


a→1

a→2

b→3

如果您想使用Jackson（一种流行的Java JSON解析器），请执行以下操作：

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new GuavaModule());
mapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);

Multimap<String, Object> data =
        mapper.readValue(json, new TypeReference<Multimap<String, Object>>() {});

一些相关详细信息：

GuavaModule是杰克逊datatype collection module，用于支持Guava类型。
通过启用ACCEPT_SINGLE_VALUE_AS_ARRAY，Jackson将执行从非JSON数组值到单元素数组的自动转换，这是将JSON解析为Multimap<K, V>所必需的。

以下依赖项是必需的：

<!-- Guava -->
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>${guava.version}</version>
</dependency>

<!-- Jackson Core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>${jackson.version}</version>
</dependency>

<!-- Jackson Databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>${jackson.version}</version>
</dependency>

<!-- Jackson module for Guava integration -->
<dependency>
  <groupId>com.fasterxml.jackson.datatype</groupId>
  <artifactId>jackson-datatype-guava</artifactId>
  <version>${jackson.version}</version>
</dependency>

要将地图转换回JSON文档，请使用：

String output = mapper.writeValueAsString(data);

Answer 2

首先检查map是否已经包含该密钥，如果是，则添加它。

如果您使用的是类似HashMap<String, List<YourObject>>的内容：

if (map.containsKey(key)) {
    map.get(key).add(yourObject);
}

如果有重复的密钥，如何在哈希映射中将密钥的值添加到另一个密钥

2 个答案: