GSON将JSON对象标识为Primitive

我正在编写一个相对简单的消息应用程序,它将日志保存为JSON格式,并使用GSON库来解析这些日志。我从服务器加载一个JSON文件,并将其放入 Gson.toJsonTree() 作用我不确定这是预期的,但当我用 isJsonSomething() 函数( isJsonObject , isJsonAray , isJsonNull , isJsonPrimitive ), isJson基元 返回true,我无法将其解析为对象。这是我的JSON文件的内容:

{
    "users": [
        {
            "picture": "", 
            "type": "user", 
            "name": "kroltan"
        }
    ], 
    "description": "No description", 
    "messages": [

        {
            "content": "something", 
            "time": "2013-08-30 00:38:17.212000", 
            "type": "message", 
            "author": "someone"
        }
    ], 
    "type": "channel", 
    "name": "default"
}

下面是用于将其解析为POJO的类:(CLEANUP注释是我从帖子中删除不相关代码的地方)

package com.example.testapp;

//CLEANUP: All needed imports

import com.example.testapp.data.*;
import com.google.gson.*;

public class JSONConverter {
    public interface JsonTypeLoadedListener {
        public void onSucess(JSONType jsonType);
        public void onFailure(Exception e);
    }
    public static final String DATE_FORMAT = "dd-MM-yyyy HH:mm:ss.SSS";
    public static final HashMap<String, Class<?>> JSON_TYPES = new HashMap<String, Class<?>>();
    public JSONConverter() {
        JSON_TYPES.clear();
        JSON_TYPES.put("channel", Channel.class);
        JSON_TYPES.put("user", User.class);
        JSON_TYPES.put("message", Message.class);
    }
    public void loadFromURL(final URL url, final JsonTypeLoadedListener listener) {
        new Thread(new Runnable() {

            @Override
            public void run() {
                JsonObject result = null;
                Gson gson = new GsonBuilder().setDateFormat(DATE_FORMAT).create();
                if (url.getProtocol().equals("http")) {
                    try {
                        String content = //Loads from a server, omitted for clarity
                        result = gson.toJsonTree(content).getAsJsonObject();
                        conn.disconnect();
                    } catch (Exception e) {
                        e.printStackTrace();
                        listener.onFailure(e);
                        return;
                    }
                } else if (url.getProtocol().equals("file")) {
                    try {
                        String content = //Loads from a file, omitted for clarity
                        result = gson.toJsonTree(content).getAsJsonObject();
                        br.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                        listener.onFailure(e);
                        return;
                    }
                }
                listener.onSucess((JSONType) gson.fromJson(result, JSON_TYPES.get(result.get("type").getAsString())));
            }

        }, "URLLoader").start();
    }
    public JSONType loadFromString(String s) {
        Gson gson = new Gson();
        JsonObject result = gson.toJsonTree(s).getAsJsonObject();
        return (JSONType) gson.fromJson(result, JSON_TYPES.get(result.get("type").getAsString()));
    }
}

课程 Message , User 和 Channel all继承自JSONType(一个自定义类,具有一个名为type的字段和一些实用程序方法),并包含上述JSON文件中存在的所有值。

当它到达时 gson.toJsonTree(content).getAsJsonObject() ,我在Logcat中得到了这个错误(为了清晰起见,省略了字符串,它只是完整的文件):

java.lang.IllegalStateException: Not a JSON Object: "String containing all the file with tabs represented as \t"