gson使用注释排除超类的字段

Question

当我使用一些ORM库(如LitePal )时，它要求我扩展它的类DataSupport，当我使用Gson将POJO转换成JSON字符串时，它会得到

{
    "age": 25,
    "sex": false,
    "height": 178,
    "username": "test",
    "weight": 65,
    "associatedModelsMapForJoinTable": {},
    "associatedModelsMapWithFK": {},
    "associatedModelsMapWithoutFK": {},
    "baseObjId": 2,
    "listToClearAssociatedFK": [],
    "listToClearSelfFK": []
}

我只需要子类(它是我的POJO-User)字段，例如：

{
    "age": 25,
    "sex": false,
    "height": 178,
    "weight": 65,
    "username": "test"
}

我的Gson版本是2.7

compile group: 'com.google.code.gson', name: 'gson', version: '2.7' 

这是DataSupport的字段

/**
 * The identify of each model. LitePal will generate the value
 * automatically. Do not try to assign or modify it.
 */
private long baseObjId;

/**
 * A map contains all the associated models' id with M2O or O2O
 * associations. Each corresponding table of these models contains a foreign
 * key column.
 */
private Map<String, Set<Long>> associatedModelsMapWithFK;

/**
 * A map contains all the associated models' id with M2O or O2O association.
 * Each corresponding table of these models doesn't contain foreign key
 * column. Instead self model has a foreign key column in the corresponding
 * table.
 */
private Map<String, Long> associatedModelsMapWithoutFK;

/**
 * A map contains all the associated models' id with M2M association.
 */
private Map<String, Set<Long>> associatedModelsMapForJoinTable;

/**
 * When updating a model and the associations breaks between current model
 * and others, if current model holds a foreign key, it need to be cleared.
 * This list holds all the foreign key names that need to clear.
 */
private List<String> listToClearSelfFK;

/**
 * When updating a model and the associations breaks between current model
 * and others, clear all the associated models' foreign key value if it
 * exists. This list holds all the associated table names that need to
 * clear.
 */
private List<String> listToClearAssociatedFK;

/**
 * A list holds all the field names which need to be updated into default
 * value of model.
 */
private List<String> fieldsToSetToDefault;

这是我的POJO类字段

public class User extends DataSupport {
    public static final String TAG = User.class.getSimpleName();
    @SerializedName("username")
    private String userName = "";
    @SerializedName("sex")
    private boolean female = false;
    @SerializedName("age")
    private int age = UserDataUtil.DEFAULT_AGE;
    @SerializedName("height")
    private int height = UserDataUtil.DEFAULT_HEIGHT;
    @SerializedName("weight")
    private int weight = UserDataUtil.DEFAULT_WEIGHT;

如何使用Gson注释排除超类DataSupport字段？

当我使用GsonBuilder.serExclusionStrategies时，例如

.setExclusionStrategies(new ExclusionStrategy() {
                @Override
                public boolean shouldSkipField(FieldAttributes f) {
                    if (f.getDeclaringClass() == DataSupport.class) {
                        String fName = f.getName();
                        if (fName.equals("associatedModelsMapForJoinTable")
                                || fName.equals("associatedModelsMapWithFK")
                                || fName.equals("associatedModelsMapWithoutFK")
                                || fName.equals("baseObjId")
                                || fName.equals("listToClearAssociatedFK")
                                || fName.equals("listToClearSelfFK")) {
                            return true;
                        }
                    }
                    return false;
                }

                @Override
                public boolean shouldSkipClass(Class<?> clazz) {
                    return false;
                }
            })

它确实有效，但我只想知道我能不能解决同样的问题，并且只在可能的情况下使用Gson的注释。

但是我不想在子类的每个字段中使用@Expose，我只想通过在超类中使用@Expose注释来排除超类的字段。

我试着用生活的方式，但它行不通：

public class DataSupport {

/**
 * The identify of each model. LitePal will generate the value
 * automatically. Do not try to assign or modify it.
 */
@Expose(serialize = false,deserialize = false)
private long baseObjId;

我的英语很差，如果我的描述让你困惑了，请告诉我，我会尽力改正的，谢谢。

Answer 1

简单，在字段的定义中使用瞬态，例如：

private transient Map<String, Set<Long>> associatedModelsMapWithFK;

这是文档。