gson 抛出 MalformedJsonException [英] gson throws MalformedJsonException

问题描述

我正在使用 gson 将 json 字符串转换为 Java 对象.result2 的值与 result1 的值完全相同.(从调试器复制；添加了反斜杠)

I'm using gson to convert a json string to a Java-Object. The value of result2 is exactly the same as the value of result1. (Copied from debugger; Backslashs added)

转换 result1 时抛出以下异常:com.google.gson.JsonSyntaxException:com.google.gson.stream.MalformedJsonException:第 1 行第 170 列的预期 EOF

The following exception is thrown while converting result1: com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Expected EOF at line 1 column 170

转换 result2 工作正常.

json 字符串根据 jsonlint.com 是有效的.

The json string is valid according to jsonlint.com.

public static Userinfo getUserinfo()
{
    String result1 = http.POST("https://www.bitstamp.net/api/balance/",
                                postdata, true);
    String result2 = "{"btc_reserved": "0", "fee": "0.5000", "btc_available": "0.10000000", "usd_reserved": "0", "btc_balance": "0.10000000", "usd_balance": "30.00", "usd_available": "30.00"}";
    Gson gson = new Gson();
    Userinfo userinfo1 = gson.fromJson(result1, Userinfo.class); //throws Exception
    Userinfo userinfo2 = gson.fromJson(result2, Userinfo.class); //works fine

    return userinfo1;
}
private class Userinfo {

    public Userinfo(){
    }

    public float usd_balance;
    public float btc_balance ;
    public float usd_reserved;
    public float btc_reserved;
    public float usd_available;
    public float btc_available;
    public float fee;
    public float last_update;
}

推荐答案

我怀疑 result1 末尾有一些字符，您在调试器中看不到 }特点.result1 与 result2 的长度是多少?我会注意到您引用的 result2 有 169 个字符.

I suspect that result1 has some characters at the end of it that you can't see in the debugger that follow the closing } character. What's the length of result1 versus result2? I'll note that result2 as you've quoted it has 169 characters.

GSON 在对象末尾有额外的不是空格的字符时抛出该特定错误，并且它非常定义了空格(就像 JSON 规范那样) - 只有 、 、 和空格算作空白.特别要注意尾随的 NUL () 字符不算作空格，会导致此错误.

GSON throws that particular error when there's extra characters after the end of the object that aren't whitespace, and it defines whitespace very narrowly (as the JSON spec does) - only , , , and space count as whitespace. In particular, note that trailing NUL () characters do not count as whitespace and will cause this error.

如果您无法轻松找出导致末尾多余字符的原因并消除它们，另一种选择是告诉 GSON 以宽松模式进行解析:

If you can't easily figure out what's causing the extra characters at the end and eliminate them, another option is to tell GSON to parse in lenient mode:

Gson gson = new Gson();
JsonReader reader = new JsonReader(new StringReader(result1));
reader.setLenient(true);
Userinfo userinfo1 = gson.fromJson(reader, Userinfo.class);

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