有没有人让Deserializer工作？我在方法＆＃34;反序列化＆＃34;中获得完整的JSON表达式而不是元素??
public static void main(String[] args) {
GsonBuilder gb = new GsonBuilder();
gb.registerTypeAdapter(DummyObject.class, new JsonSerializer<Date>() {
public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
System.out.println("serialize...");
return new JsonPrimitive(DateUtil.toString(src));
}
});
gb.registerTypeAdapter(DummyObject.class, new JsonDeserializer<Date>() {
DateFormat format = DateFormat.getInstance();
public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
if (!(json instanceof JsonPrimitive)) {
throw new JsonParseException("The date should be a string value");
}
try {
return format.parse(json.getAsString());
} catch (ParseException e) {
throw new JsonParseException(e);
}
}
});
String jsonExp = "{\"createdDate\":\"2011-12-27T15:21:16\"}";
Gson g = gb.create();
DummyObject tf = g.fromJson(jsonExp, DummyObject.class);
}
答案 0 :(得分：50)
Gson gson = new GsonBuilder()
.setDateFormat("yyyy-MM-dd'T'HH:mm:ssz")
.create();
答案 1 :(得分：2)
在这里，您可以使用自定义Gson构建器来处理几乎所有日期模式 使用JodaTime（如果不想使用它，可以排除它，它只是扩大了可能性）
public class MyGsonBuilder {
public static <T> List<T> toList(String json, Class<T> clazz) {
if (null == json) {
return null;
}
Gson gson = build();
return gson.fromJson(json, new TypeToken<T>() {
}.getType());
}
private static boolean enableLog = false;
private static void log(String log) {
if (enableLog) Log.d("DEBUG_GSON_TIME", log);
}
static List<SimpleDateFormat> knownPatterns = new ArrayList<>(Arrays.asList(
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ"),
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ"),
new SimpleDateFormat("yyyy-MM-dd' 'HH:mm:ss"),
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"),
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss")
));
static JsonSerializer<Date> ser = new JsonSerializer<Date>() {
@Override
public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
return new GsonBuilder().create().toJsonTree(buildIso8601Format().format(src));
}
};
static JsonDeserializer<Date> deser = new JsonDeserializer<Date>() {
@Override
public Date deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
Date date = null;
try {
// Take a try
String dateString = json.getAsJsonPrimitive().getAsString();
log("deserialize date string = " + dateString);
date = buildOddFormat().parse(dateString);
log(" pattern (yyyy-MM-dd HH:mm:ss) = SUCCESS " + dateString + " = " + date.toString());
} catch (Throwable t) {
// Loop on
log(" pattern (yyyy-MM-dd HH:mm:ss) = error = " + t.getMessage());
}
if (date == null) {
try {
// Take a try
String dateString = json.getAsJsonPrimitive().getAsString();
date = buildOldFormat().parse(dateString);
log(" pattern (MMM dd, yyyy HH:mm:ss) = SUCCESS " + dateString + " = " + date.toString());
} catch (Throwable t) {
// Loop on
log(" pattern (MMM dd, yyyy HH:mm:ss) = error = " + t.getMessage());
}
}
if (date == null) {
try {
// Take a try
String dateString = json.getAsJsonPrimitive().getAsString();
date = buildVeryOldFormat().parse(dateString);
log(" pattern (MMM d, yyyy HH:mm:ss) = SUCCESS " + dateString + " = " + date.toString());
} catch (Throwable t) {
// Loop on
log(" pattern (MMM d, yyyy HH:mm:ss) = error = " + t.getMessage());
}
}
if (date == null)
for (SimpleDateFormat pattern : knownPatterns) {
try {
// Take a try
if (!pattern.toPattern().contains("Z"))
pattern.setTimeZone(TimeZone.getTimeZone("UTC"));
String dateString = json.getAsJsonPrimitive().getAsString();
if (!pattern.toPattern().contains("Z"))
pattern.setTimeZone(TimeZone.getTimeZone("UTC"));
date = new Date(pattern.parse(dateString).getTime());
log(" pattern (" + pattern.toPattern() + ") = SUCCESS " + dateString + " = " + date.toString());
break;
} catch (Throwable t) {
// Loop on
log(" pattern (" + pattern.toPattern() + ") = error = " + t.getMessage());
}
}
// }
if (date == null) {
try {
date = new Date(json.getAsJsonPrimitive().getAsLong());
log(" Joda = SUCCESS " + json.getAsJsonPrimitive().getAsString() + " = " + date.toString());
} catch (Throwable t) {
log(" pattern (Long) = error = " + t.getMessage());
}
}
if (date == null) {
try {
date = DateFormat.getInstance().parse(json.getAsJsonPrimitive().getAsString());
log(" Joda = SUCCESS " + json.getAsJsonPrimitive().getAsString() + " = " + date.toString());
} catch (Throwable t) {
log(" pattern ( DateFormat.getInstance().parse()) = error = " + t.getMessage());
}
}
if (date == null) {
DateTimeFormatter fmt = ISODateTimeFormat.dateTime();
try {
String dateString = json.getAsJsonPrimitive().getAsString();
date = fmt.parseDateTime(dateString).toDate();
log(" Joda = SUCCESS " + dateString + " = " + date.toString());
} catch (Throwable t) {
// Loop on
log(" Joda error = " + t.getMessage());
Crashlytics.logException(new Throwable("NON PARSABLE DATE!!! = " + json.toString()));
}
}
if (date == null)
date = new Date();
return date;
}
};
private static DateFormat buildIso8601Format() {
DateFormat iso8601Format = new SimpleDateFormat(
"yyyy-MM-dd'T'HH:mm:ss.SSSZ");
return iso8601Format;
}
private static DateFormat buildOddFormat() {
DateFormat iso8601Format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC"));
return iso8601Format;
}
private static DateFormat buildOldFormat() {
DateFormat iso8601Format = new SimpleDateFormat("MMM dd, yyyy HH:mm:ss");
iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC"));
return iso8601Format;
}
private static DateFormat buildVeryOldFormat() {
DateFormat iso8601Format = new SimpleDateFormat("MMM d, yyyy HH:mm:ss");
iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC"));
return iso8601Format;
}
static public Gson build() {
Gson gson = new GsonBuilder()
//.setDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ")
.registerTypeAdapter(Date.class, deser)
.registerTypeAdapter(Date.class, ser)
.excludeFieldsWithoutExposeAnnotation()
.create();
return gson;
}
}
答案 2 :(得分：-2)
使用原始问题中的代码，使用Gson 1.7.1或Gson 2.0，我得到的是“线程中的异常”main“com.google.gson.JsonParseException：日期应该是字符串值”。这就是我期望编写的代码。
我猜你可能想为java.util.Date注册一个类型适配器，而不是DummyObject。 （这导致了一个不同的错误，但我认为它更接近你想要实现的目标。当然，我正在猜测问题/代码的意图。）
或许您想要沿着以下几行更改反序列化逻辑，理解您只想将JSON的日期部分反序列化为java.util.Date。
gb.registerTypeAdapter(DummyObject.class, new JsonDeserializer<Date>()
{
DateFormat format = DateFormat.getInstance();
public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
throws JsonParseException
{
try
{
return format.parse(((JsonObject)json).get("createdDate").getAsString());
}
catch (ParseException e)
{
throw new JsonParseException(e);
}
}
});
您仍然需要解决（更具体的）日期解析错误。