如何使用Jackson-MismatchdinPutException反序列化Java字符串中的json字符串
我正在尝试反序列化字符串中的json字符串。我从另一个系统得到这个响应并处理来自卡夫卡的响应,所以我没有选择更改发布代码。额外的引号是个问题,但由于它是来自不同系统的消息,我的输入是固定的如何使用Jackson-MismatchdinPutException反序列化Java字符串中的json字符串,java,jackson,Java,Jackson,我正在尝试反序列化字符串中的json字符串。我从另一个系统得到这个响应并处理来自卡夫卡的响应,所以我没有选择更改发布代码。额外的引号是个问题,但由于它是来自不同系统的消息,我的输入是固定的 @Data @ToString @AllArgsConstructor @NoArgsConstructor public class TestModel { private Model model; } @Data @ToString @AllArgsConstructor @NoArgsCons
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class TestModel {
private Model model;
}
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Model {
private String message;
}
驱动程序代码:
String t = "\"{\\\"model\\\":{\\\"message\\\":\\\"sample\\\"}}\"";
System.out.println(objectMapper.readValue(t, TestModel.class)) //Exception
当我尝试像上面那样反序列化同一个字符串时,我得到以下异常
Exception in thread "main" com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `test.TestModel` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"model":{"message":"sample"}}')
at [Source: (String)""{\"model\":{\"message\":\"sample\"}}""; line: 1, column: 1]
at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1343)
at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1032)
at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371)
at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1373)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3004)
at Sample.main(Sample.java:15)
有人能给我一些建议吗?像这样的办法行得通
String t = "\"{\\\"message\\\":\\\"test\\\"}\"";
ObjectMapper mapper = new ObjectMapper();
mapper.enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
JsonFactory factory = mapper.getFactory();
JsonParser createParser = factory.createParser(t);
JsonNode actualObj1 = mapper.readTree(createParser);
TestModel t11 = mapper.readValue(actualObj1.asText(), TestModel.class);
System.out.println(t11.getMessage());
下面是TestModel类
public class TestModel {
public TestModel() {
}
@JsonProperty("message")
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
}
“没有从字符串值反序列化的字符串参数构造函数/工厂方法”--您认为这意味着什么?向我们展示
TestModel
的代码。您不能反序列化到一个对象-这只是一个字符串,如起始转义引号所示。当您解析时,Javascript可能也会返回一个字符串。为什么要更改输入字符串?问题是,这不可能modified@OneCricketeer我已经更新了答案,请检查。