Java JsonObject 添加属性 - 地图
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JsonObject add property - maps
提问by harsh
I have a class called Test with a String idfield and a HashMap maplike Map<String, String[]>, Map<String, ArrayList<String>>, and Map<String, HashMap>(Here the second HashMapis a <String, Integer>one) I have the following code.
我有一个名为测试与类String id字段和HashMap map像 Map<String, String[]>，Map<String, ArrayList<String>>和Map<String, HashMap>（这里第二个HashMap是<String, Integer>一个）我有下面的代码。
JsonObject jsonObject = new JsonObject();
jsonObject.addProperty("id", test.getId);
Like this, I want to add the Map to this. Adding like jsonObject.addProperty("map", String.valueOf(test.getMap()));does not do the work properly as it add "(commas) to beginning and end. Can somebody tell me what is the correct way to do it?
像这样，我想将地图添加到此。添加 likejsonObject.addProperty("map", String.valueOf(test.getMap()));并不能正常工作，因为它将“（逗号）添加到开头和结尾。有人能告诉我什么是正确的方法吗？
采纳答案by Sotirios Delimanolis
JsonObjecthas addmethod to add primitives, but only a single addmethod to add complex types. This method expects a JsonElementso that's what you have to create.
JsonObject有add添加基元的方法，但只有一个add方法来添加复杂类型。此方法需要 aJsonElement所以这就是您必须创建的。
JsonObject jsonObject = new JsonObject();
Gson gson = new Gson();
JsonElement jsonElement = gson.toJsonTree(test.getMap());
jsonObject.add("map", jsonElement);
I don't know exactly why you're doing this. In your last question, I showed you how to generate full JSON from the Testclass.
我不知道你为什么要这样做。在您的上一个问题中，我向您展示了如何从Test类中生成完整的 JSON 。
You can use
您可以使用
gson.toJsonTree(test);
to get the JSON as a JsonElement, which you can cast to a JsonObject.
将 JSON 作为 a 获取JsonElement，您可以将其强制转换为JsonObject.
