使用jackson objectmapper反序列化时，如果字符串未双引号，则抛出错误

Question

我有一个JSON：

{
    "stringField" : 1234,
    "booleanField": true,
    "numberField": 1200.00
}

我使用对象映射器将json反序列化为：-

@Data
class SomeClass {
    String stringField;
    boolean booleanField;
    float numberField;
}

我希望ObjtMapper抛出错误，因为String字段的值必须根据json规范双引号。如何让ObjtMapper抛出错误？

Answer 1

你只需要这样设置jackson objectmapper

JsonFactory factory = new JsonFactory();
factory.disable(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES);
ObjectMapper mapper = new ObjectMapper(factory)

这将在序列化/反序列化期间引发错误

Answer 2

这应该可以解决您的问题。

class SomeClass {
    @JsonDeserialize(using=ForceStringDeserializer.class)
    public String stringField;
    public boolean booleanField;
    public float numberField;
}


class ForceStringDeserializer extends JsonDeserializer<String> {
    @Override
    public String deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
        if (jsonParser.getCurrentToken() != JsonToken.VALUE_STRING) {
            throw deserializationContext.wrongTokenException(jsonParser, JsonToken.VALUE_STRING, "Attempted to parse Integer to String but this is forbidden");
        }
        return jsonParser.getValueAsString();
    }
}

Answer 3

您可以编写自定义字符串反序列化器。（我假设您正在使用spring）

@Configuration
public class JacksonConfiguration {

    @Bean
    SimpleModule jacksonDeserializerConfiguration() {
        SimpleModule module = new SimpleModule();
        module.addDeserializer(String.class, new StdDeserializer<String>(String.class) {
        @Override
        public String deserialize(JsonParser parser, DeserializationContext context)
                throws IOException {
             if (!parser.hasToken(JsonToken.VALUE_STRING)) {
                //throw ex what do u want
                throw new RuntimeException("String not include quote");
            }
            return StringDeserializer.instance.deserialize(parser, context);
        }
    });
        return module;
    }
}