如果有任何重复的键，如何将键的值添加到哈希图中的另一个键

Question

我正在尝试将 json 数据放入可能包含许多重复键的 HashMap 中。 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"

    },
}

在上面的json文件中，“成员详细信息”被认为是键，括号内的数据被认为是值。但这里的问题是上面的 json 示例中可能存在重复的键，例如“Physician”。

我想将第二个“医生”的值添加到第一个“医生”而不覆盖其值并删除重复的键。 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"
    },
    {
        "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 附带Multimap<K, V>。这正是您正在寻找的：

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相关联。您可以将多重映射的内容可视化为从键到非空值集合的映射：

• a → 1, 2
• b → 3

...或作为单个“扁平化”键值对集合：

• a → 1
• a → 2
• b → 3

---

如果您想使用Jackson，这是一种流行的 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>>() {});

一些相关细节：

• GuavaModule 是 Jackson 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。

  李>

需要以下依赖项：

<!-- 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。

如果你使用类似HashMap<String, List<YourObject>>:

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