Gson如何获取序列化名称

Question

When we define a class with following format

public class Field {
    @SerializedName("name")
    public String name;
    @SerializedName("category")
    public String category;

}

for the JsonObject content

{
    "name" : "string",
    "category" : "string",
}

and using Gson to parse the content

Field field = new GsonBuilder().create().fromJson(
                content, Field.class);

So,my question is can we use Gson to get the @Serialized name. For in this instance I want to know what @Serialized name is used for field.name ,which is name and for field.category which is category .

As per suggested by @Sotirios Delimanolis, using Reflection we can get the Serialized name

java.lang.reflect.Field fields = Field.class.getDeclaredField("name");             
SerializedName sName =fields.getAnnotation(SerializedName.class);            
System.out.println(sName.value()); 

Answer 1

Use reflection to retrieve the Field object you want. You can then use Field#getAnnotation(Class) to get a SerializedName instance on which you can call value() to get the name.

Answer 2

Instead of parsing with Field.class , can't you parse it into a JsonObject.class instead? Then use JsonObject.get() :

import com.google.gson.JsonObject;

Gson gson = new GsonBuilder().create();
JsonObject jsonObject = gson.fromJson(content, JsonObject.class);
String serializedName = jsonObject.get("name").getAsString();

Note that .getAsString() will return it as a String without embedded double quotes, compare this to when you call toString() .

---

One thing I was trying to do was serialize an enum field, which is not an object. In that case, you can serialize using JsonElement.class , since it's just a primitive:

import com.google.gson.JsonElement;

Gson gson = new GsonBuilder().create();
JsonElement jsonElement = gson.fromJson("\"a\"", JsonElement.class);
String serializedName = jsonElement.getAsString();

Answer 3

Thats a way with alternate for example for a more complex example

Enum class

public enum SomeStatusCd {

    @SerializedName(
        value = "status_1",
        alternate = {"an alternate 1", "an alternate 2"}
    )
    STATUS_1("status_1")
    ....
}

get the enum from alternate

public static SomeStatusCd getFromAlternate(String alternateFieldName){
    SomeStatusCd result = null;
    Field[] statusDeclaredFields = SomeStatusCd.class.getDeclaredFields();
    String foundEnumName = null;
    for (Field statusDeclaredField : statusDeclaredFields) {
        SerializedName annotation = statusDeclaredField.getAnnotation(SerializedName.class);
        if (annotation != null){
            String[] declaredFieldAlternates = annotation.alternate();
            for (String declaredFieldAlternate : declaredFieldAlternates) {
                if (declaredFieldAlternate.equals(alternateFieldName)){
                    foundEnumName = statusDeclaredField.getName();
                }
            }
        }
    }
    if (foundEnumName != null){
        for (SomeStatusCd enumConstant : SomeStatusCd.class.getEnumConstants()) {
            if (enumConstant.name().equals(foundEnumName)){
                result = enumConstant;
            }
        }
    }

    return result;
}

Test it

    SomeStatusCd fromAlternate = getFromAlternate("an alternate 1");
    assertSame(fromAlternate, SomeStatusCd.STATUS_1);