Gson忽略映射中键的自定义序列化程序

Question

HashMap<Test, List<Something>> map = 
  new HashMap<>();

class Test {
 public Test(){}
 public Test(String str){test = str;}
 String test;
}

class Something {
 public Something(){}
 public Something(String str){something = str;}
 String something;
}

List<Something> somelist = new ArrayList<Something>();

somelist.add(new Something("something1"));
somelist.add(new Something("something2"));

map.put(new Test("test1"), somelist);

{
  "test.TestJsonClass$Test@15db9742": [
    {
      "string": "something1"
    },
    {
     "string": "something2"
    }
  ]
}

Gson gson = new GsonBuilder().setPrettyPrinting()
    .registerTypeAdapter(Test.class, new JsonSerializer<Test>() {
      public JsonElement serialize(Test arg0, Type arg1,
          JsonSerializationContext arg2) {
        return new JsonPrimitive(arg0.test);
      }
    }).registerTypeAdapter(Something.class, new JsonSerializer<Something>() {

      @Override
      public JsonElement serialize(Something arg0, Type arg1,
          JsonSerializationContext arg2) {
        return new JsonPrimitive(arg0.something);
      }
    }).create();

{
  "test.TestJsonClass$Test@15db9742": [
    "something1",
    "something2"
 ]
}

如何使Gson正确序列化我的密钥？

Answer 1

我发现的最简单的方法似乎是在最初构建Gson对象时设置enableComplexMapKeySerialization（）选项。

这迫使Gson使用标准规则序列化键，而不仅仅是调用toString（）。然后，您可以根据需要添加自己的序列化/反序列化程序，或者让Gson处理它。

更多信息请参见