java - 将映射值添加到具有相同关键字段名称的 JSON 对象

Question

我有以下 Java map 。 Map<String, String>包含以下值:

876234876, google
mike@hotmail, hotmail
9879892, google

我需要将其转换为以下 JSON 对象结构，而 Java JSON 对象不是我的 friend 。

"addresses" : [
    { "address":"876234876", "domain":"google" },
    { "address":"mike@hotmail", "domain":"hotmail" },
    { "address":"9879892", "domain":"google" }
]

Answer 1

要创建您要求的 JSON，您需要插入 JSONObject进入JSONArray 。所以对于每个 Entry您的Map<String, String> ，创建一个JSONObject喜欢 {"address": entry.key, "domain": entry.value}并将它们添加到 JSONArray .

让我们使用Stream.map创建该对象并将结果直接插入数组:

public static JSONObject createJson(Map<String, String> value) {
    JSONObject result = new JSONObject();
    JSONArray addresses = new JSONArray();
    result.put("addresses", addresses);

    value.entrySet().stream()       //iterate the map
        .map(e -> {                 //build an object
            JSONObject address = new JSONObject();
            address.put("address", e.getKey());
            address.put("domain", e.getValue());
            return address;
        })
        .forEach(addresses::put);   //insert into the array

    return result;
}

并使用以下命令进行测试:

public static void main(String[] args) {
    Map<String, String> values = new HashMap<>();
    values.put("876234876", "google");
    values.put("mike@hotmail", "hotmail");
    values.put("9879892", "google");
    System.out.println(createJson(values).toString(4));
}

结果:

{"addresses": [
    {
        "address": "9879892",
        "domain": "google"
    },
    {
        "address": "876234876",
        "domain": "google"
    },
    {
        "address": "mike@hotmail",
        "domain": "hotmail"
    }
]}

使用API​​:JSON In Java

<!-- https://mvnrepository.com/artifact/org.json/json -->
<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20180130</version>
</dependency>