无法用List使用Gson反序列化对象 [英] Failed to deserialize an object with List using Gson

问题描述

使用Gson将JSON反序列化为对象时，出现以下异常：

I have the following exception while deserializing an JSON to object using Gson:

com.google.gson.JsonParseException：JsonDeserializer com .google.gson.DefaultTypeAdapters $ CollectionTypeAdapter @ 588722d6无法反序列化json对象[{time：1378911600000，total：0}，{time：1378912500000，total：0}，{time：1378913400000 ，total：2，sum：130000，avgLen：65000.0}]给定类型com.google.gson.ParameterizedTypeImpl@490ca2fa

com.google.gson.JsonParseException: The JsonDeserializer com.google.gson.DefaultTypeAdapters$CollectionTypeAdapter@588722d6 failed to deserialized json object [{"time":1378911600000,"total":0},{"time":1378912500000,"total":0},{"time":1378913400000,"total":2,"sum":130000,"avgLen":65000.0}] given the type com.google.gson.ParameterizedTypeImpl@490ca2fa

应该代表JSON的类是：

The class which should represent the JSON is:

public class Api{

   private List<ApiData> avgEngLength;

   public Api() {
   }
}

public class ApiData{

private Long time;
private Long total;
private Long sum;
private Double avgLen;

public ApiData(Long time, Long total, Long sum, Double avgLen) {
    this.time = time;
    this.total= total;
    this.sum= sum;
    this.avgLen= avgLen;
 }
}

反序列化的代码是：

 String json = "{\"avgEngLength\":[{\"time\":1378905300000,\"total\":0},{\"time\":1378906200000,\"total\":2,\"sum\":130000,\"avgLen\":65000.0}]}";
 Gson gson = new GsonBuilder().create();
 return gson.fromJson(json, Api.class);

奇怪的是，它可以在一些机器上运行，而不是在其他机器上运行。
任何想法？

The odd thing is that it works on some machines and not on others. Any idea?

推荐答案

我尝试过你的例子：

I tried your example with this:

public static void main(String[] args) {

    String s = "{\"avgEngLength\":[{\"time\":1378905300000,\"total\":0},{\"time\":1378906200000,\"total\":2,\"sum\":130000,\"avgLen\":65000.0}]}";

    Gson gson = new GsonBuilder().create();
    Api a = gson.fromJson(s, Api.class);
    System.out.println(a);
    }

它的工作原理（请注意，您的示例中的字符串没有转义引号） 。

and it worked (pay attention that your string in example has no escaped quotes).

Api [avgEngLength=[ApiData [time=1378905300000, total=0, sum=null, avgLen=null], ApiData [time=1378906200000, total=2, sum=130000, avgLen=65000.0]]]

猜测你的团队正在使用不同版本的图书馆。我正在使用Gson 2.2.4，并检查了源代码：库中没有该错误字符串。

So my best guess it that your team is working with different versions of the library. I'm using Gson 2.2.4 and I checked the source code: that error string is not present in the library.

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