问题描述
我需要帮助，如何使用杰克逊和自定义解串器反序列化字典。
现在我有一个与.NET（C＃）服务器的Android应用程序通信。他们使用JSON进行通信。
在JAVA方面，我使用的是Jackson来处理JSON，而在.NET端我正在使用内置的DataContractSerializer我知道，ppl将开始评论我应该使用别的东西，但我不是这样... ;-)）
问题是我从C＃发送字典，我想要将它反序列化为JAVA方面的HashMaps，但是我没有找到一个很好的资源来解决这个问题。
我发送的一个字典的一个例子来自C＃：
//这里，对象设备是关键字，下面的int表示金额
[ DataMember]
public Dictionary< Equipment，int> EquipmentList {get;组;
仅供参考，C＃中的Equipment对象：
[DataContract]
public class Equipment
{
[DataMember]
public uint Id {get;组; }
[DataMember]
public string Name {get;组;
public override bool Equals（object obj）
{
if（obj.GetType（）！= this.GetType（））
return false;
设备e =（设备）obj;
return e.Id == this.Id;
}
}
它在C＃端正确地序列化为体面的JSON ，字典如下所示：
// ....
EquipmentList：[
{
Key：{
EquipmentId：123，
Name：MyName
}，
Value：1
我已经添加了一个自定义序列化程序（CustomMapSerializer），它是一个自定义序列化程序（CustomMapSerializer）像这样： public static ObjectMapper mapper = new ObjectMapper（）;
private static SimpleDeserializers simpleDeserializers = new SimpleDeserializers（）;
private static StdDeserializerProvider sp = new StdDeserializerProvider（）;
public static void InitSerialization（）
{
simpleDeserializers.addDeserializer（String.class，new CustomStringDeserializer（））;
simpleDeserializers.addDeserializer（Map.class，new CustomMapDeserializer（））;
sp.withAdditionalDeserializers（simpleDeserializers）;
mapper.setDeserializerProvider（sp）;
}
并像这样装饰字段：
@JsonDeserialize（using = CustomMapDeserializer.class）
public Map< Equipment，Integer>设备清单;
最后，当我运行它时，我会在定制的deserializer类中休息一下，但我不知道如何从这里进行：
public class CustomMapDeserializer extends JsonDeserializer< Map> {
@Override
public Map deserialize（JsonParser arg0，DeserializationContext arg1）throws IOException，JsonProcessingException
{
return new HashMap< Object，Object>（）; //< - 我可以在这里打破
}
}
所以，我想要的是一些关于如何创建一个具有正确值的HashMap的输入，即反序列化的设备作为键值和Int值。
$ b任何人可以帮助谁？ =）解决方案好的，经过一段时间的测试和研究，这是我想出来的。
$ b
自定义解串器如下所示：
public class CustomMapCoTravellerDeserializer extends JsonDeserializer< Map> {
@Override
public Map deserialize（JsonParser jp，DeserializationContext arg1）throws IOException，JsonProcessingException
{
HashMap&CoTravellers，Integer& myMap = new HashMap&CoTravellers，Integer>（）;
CoTravellers ct = new CoTravellers（）;
jp.nextToken（）; // {
jp.nextToken（）; // Key
jp.nextToken（）; // {
jp.nextToken（）; //CoTravellerId
jp.nextToken（）; // CoTravellerId Id
int coTravellerValue = jp.getIntValue（）;
jp.nextToken（）; // Name
jp.nextToken（）; //名称值
String coTravellerName = jp.getText（）;
jp.nextToken（）; //}
jp.nextToken（）; //Value
jp.nextToken（）; //值
int nbr = jp.getIntValue（）;
ct.CoTravellerId = coTravellerValue;
ct.Name = coTravellerName;
myMap.put（ct，nbr）;
返回myMap;
}
}
我认为这将工作，如果我只能弄清楚我正在获得的JsonMappingException ...但是我会分别发布=）
to sum it up before the wall of text below :-)
I need help with how to deserialize a Dictionary using Jackson and a custom deserializer.
Right now I have an Android app communication with a .NET (C#) server. They use JSON to communicate.
On the JAVA-side, I am using Jackson to handle the JSON and on the .NET-side I am using the built in DataContractSerializer (I know, ppl will start commenting I should use something else, but Im not so... ;-) )
The problem is that I am sending Dictionaries from C# and I want that to be deserialized to HashMaps om the JAVA-side, but I havent found a good resource for how to do that.
One example of a Dictionary I am sending from C#:
// Here, the object Equipment is the key, and the int following indicates the amount
[DataMember]
public Dictionary<Equipment, int> EquipmentList { get; set; }
And just for reference, the Equipment object in C#:
[DataContract]
public class Equipment
{
[DataMember]
public uint Id { get; set; }
[DataMember]
public string Name { get; set; }
public override bool Equals(object obj)
{
if (obj.GetType() != this.GetType())
return false;
Equipment e = (Equipment)obj;
return e.Id == this.Id;
}
}
Its serialized correctly into decent JSON on the C#-side, the Dictionary looks like this:
//....
"EquipmentList":[
{
"Key":{
"EquipmentId":123,
"Name":"MyName"
},
"Value":1
}
//....
I have added a custom serializer (CustomMapSerializer), like this:
public static ObjectMapper mapper = new ObjectMapper();
private static SimpleDeserializers simpleDeserializers = new SimpleDeserializers();
private static StdDeserializerProvider sp = new StdDeserializerProvider();
public static void InitSerialization()
{
simpleDeserializers.addDeserializer(String.class, new CustomStringDeserializer());
simpleDeserializers.addDeserializer(Map.class, new CustomMapDeserializer());
sp.withAdditionalDeserializers(simpleDeserializers);
mapper.setDeserializerProvider(sp);
}
And decorated the field like this:
@JsonDeserialize(using=CustomMapDeserializer.class)
public Map<Equipment, Integer> EquipmentList;
And finally, when I run it I do get a break in the custom deserializer class, but I am not sure how to proceed from here:
public class CustomMapDeserializer extends JsonDeserializer<Map> {
@Override
public Map deserialize(JsonParser arg0, DeserializationContext arg1) throws IOException, JsonProcessingException
{
return new HashMap<Object, Object>(); // <-- I can break here
}
}
So, what I would like is some input on how to create a HashMap with the correct values in it, ie a deserialized Equipment as Key and an Int as value.
Anyone out there who can assist? =)
解决方案 Ok, after a while testing and researching, this is what I came up with.
The custom deserializer looks like this:
public class CustomMapCoTravellerDeserializer extends JsonDeserializer<Map> {
@Override
public Map deserialize(JsonParser jp, DeserializationContext arg1) throws IOException, JsonProcessingException
{
HashMap<CoTravellers, Integer> myMap = new HashMap<CoTravellers, Integer>();
CoTravellers ct = new CoTravellers();
jp.nextToken(); // {
jp.nextToken(); // Key
jp.nextToken(); // {
jp.nextToken(); // "CoTravellerId"
jp.nextToken(); // CoTravellerId Id
int coTravellerValue = jp.getIntValue();
jp.nextToken(); // Name
jp.nextToken(); // Name Value
String coTravellerName = jp.getText();
jp.nextToken(); // }
jp.nextToken(); // "Value"
jp.nextToken(); // The value
int nbr = jp.getIntValue();
ct.CoTravellerId = coTravellerValue;
ct.Name = coTravellerName;
myMap.put(ct, nbr);
return myMap;
}
}
I think this will work, if I can only figure out the JsonMappingException I am getting... but I will post on that separately =)
这篇关于如何使用杰克逊正确地反序列化.NET字典？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！