Java 解析日期Gson:NumberFormatException

我对java和Gson相当陌生，我一直在尝试解析nobelprize.org api中的一些数据。我能够解析一些信息，但当我包含日期时，我似乎总是出错。我将如何着手修复此错误

我尝试了.setDateFormatyyyy-MM-dd，但仍然出现相同的错误

Gson mainparser = new GsonBuilder()
.setDateFormat("yyyy-MM-dd")
.create();

mainparser.fromJson(line, ParsedJson.class);

*编辑：示例Json

    "laureates": [
        {
            "id": "1",
            "firstname": "Wilhelm Conrad",
            "surname": "Röntgen",
            "born": "1845-03-27",
            "died": "1923-02-10",
            "bornCountry": "Prussia (now Germany)",
            "bornCountryCode": "DE",
            "bornCity": "Lennep (now Remscheid)",
            "diedCountry": "Germany",
            "diedCountryCode": "DE",
            "diedCity": "Munich",
            "gender": "male",
            "prizes": [
                {
                    "year": "1901",
                    "category": "physics",
                    "share": "1",
                    "motivation": "\"in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him\"",
                    "affiliations": [
                        {
                            "name": "Munich University",
                            "city": "Munich",
                            "country": "Germany"
                        }
                    ]
                }
            ]
        },
]

您可以尝试对日期属性使用JsonDeserializer

public class DateDeserializer implements JsonDeserializer<Date> {

   public DateDeserializer() {
   }

    @Override
    public Date deserialize(JsonElement element, Type arg1, JsonDeserializationContext arg2) throws JsonParseException {
        String dateStr = element.getAsString();
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
        try {
            return format.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
}

---

你能把这封信寄出去吗response@Nomanaliabbasi在编辑复选框中添加了此选项。我建议您不要使用日期。那门课设计得很糟糕，而且早已过时。改为使用localdatefrom。您确定id:1有效吗？在您的代码中，它被定义为int。这是一个愚蠢的问题，但如何根据您的答案实现JsonDeserializer类呢。我似乎得到了这样的结论：DateDeserializer不是抽象的，也不会重写抽象方法，而且@override:method也不会重写或实现超类型的方法。我不确定我是否理解您的问题，但是。我想你认为JsonDeserializer是一个自定义类，但它是gson的类。哦，很抱歉，我想说的是如何包含DateDeserializer类，因为目前它似乎没有覆盖JsonDeserializer中的方法，并且给了我上面的非抽象/不覆盖错误。JsonDeserializer不是一个抽象类。这是一个接口。你不应该有任何错误。我不知道你为什么会犯这样的错误。您只需要创建一个java文件并复制粘贴上面的DateDeserializer类。

java.lang.reflect.InvocationTargetException

Caused by: com.google.gson.JsonSyntaxException: java.lang.NumberFormatException: For input string: "1845-03-27"

Caused by: java.lang.NumberFormatException: For input string: "1845-03-27"

    "laureates": [
        {
            "id": "1",
            "firstname": "Wilhelm Conrad",
            "surname": "Röntgen",
            "born": "1845-03-27",
            "died": "1923-02-10",
            "bornCountry": "Prussia (now Germany)",
            "bornCountryCode": "DE",
            "bornCity": "Lennep (now Remscheid)",
            "diedCountry": "Germany",
            "diedCountryCode": "DE",
            "diedCity": "Munich",
            "gender": "male",
            "prizes": [
                {
                    "year": "1901",
                    "category": "physics",
                    "share": "1",
                    "motivation": "\"in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him\"",
                    "affiliations": [
                        {
                            "name": "Munich University",
                            "city": "Munich",
                            "country": "Germany"
                        }
                    ]
                }
            ]
        },
]

public class DateDeserializer implements JsonDeserializer<Date> {

   public DateDeserializer() {
   }

    @Override
    public Date deserialize(JsonElement element, Type arg1, JsonDeserializationContext arg2) throws JsonParseException {
        String dateStr = element.getAsString();
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
        try {
            return format.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
}

public class Laureates {
    int id;
    String firstname;
    String surname;
    @JsonAdapter(DateDeserializer.class)
    Date born;
    @JsonAdapter(DateDeserializer.class)
    Date died;
    String bornCountry;
    String bornCountryCode;
    String bornCity;
    String diedCountry;
    String diedCountryCode;
    String diedCity;
    String gender;
    List<Prizes> prizes;
...Getters/Setters

}