Could not read JSON: Can not construct instance of java.util.Date

I have a Rest service which takes a parameter "timestamp"of Date type. I am getting following exception when I make request to this service:

Following is my sample request :

{
"status" : "EMPLOYEE_ADDED",
"timestamp" : "2015-11-04T15:53Z"
}

16:30:37.105 [[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)'] DEBUG o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver -
Resolving exception from handler [public org.springframework.http.HttpEntity<com.test.Response>
com.test.rest.controller.TestRestController.updateStatus(com.test.model.StatusRequest)]:
org.springframework.http.converter.HttpMessageNotReadableException:
Could not read JSON: Can not construct instance of java.util.Date from String value '2015-11-04T15:53Z': not a valid representation (error: Failed
to parse Date value '2015-11-04T15:53Z': Can not parse date "2015-11-04T15:53Z": not compatible with any of standard forms ("yyyy-MM-dd'T'HH:mm:ss.SSSZ", "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", "EEE, dd MMM yyyy HH:mm:ss zzz", "yyyy-MM-dd"))

Solution:

This kind of exception is thrown when passed value can not be parsed to target type. We can override the serilization and deserialization behavior by using @JsonSerialize and @JsonDeserialize annotations.

I created a custom Serializer and Deserializer class and used it with @JsonSerialize and @JsonDeserialize annotation as shown below. I added these annotation in StatusRequest class which the request object for my rest service:

import java.util.Date;

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;

import com.fasterxml.jackson.databind.annotation.JsonSerialize;

import com.custom.DateTimeJsonDeserializer;

import com.custom.DateTimeJsonSerializer;

public class StatusRequest {

         private Date timestamp;

        /**

* @return the timestamp

*/

@JsonSerialize(using = DateTimeJsonSerializer.class)

public Date getTimestamp() {

return timestamp;

}

/**

* @param timestamp the timestamp to set

*/

@JsonDeserialize(using = DateTimeJsonDeserializer.class)

public void setTimestamp(Date timestamp) {

this.timestamp = timestamp;

}

}

• Custom Deserializer :

package com.custom;

import java.io.IOException;

import java.text.ParseException;

import java.util.Date;

import java.util.TimeZone;

import org.apache.commons.lang3.StringUtils;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.core.JsonParser;

import com.fasterxml.jackson.core.JsonProcessingException;

import com.fasterxml.jackson.databind.DeserializationContext;

import com.fasterxml.jackson.databind.JsonDeserializer;

import com.fasterxml.jackson.databind.JsonMappingException;

import com.fasterxml.jackson.databind.util.ISO8601DateFormat;

/**

 * JSON Deserializer to parse dates in ISO-8601 standard date/time format.

 *

 * @author Sanjay Ingole

 */

public class DateTimeJsonDeserializer extends JsonDeserializer<Date> {

private static final Logger LOG = LoggerFactory.getLogger(DateTimeJsonDeserializer.class);

/** UTC (GMT) timezone. */

private static final TimeZone UTC = TimeZone.getTimeZone("UTC");

/**

* Constructor.

*/

public DateTimeJsonDeserializer() {

super();

}

@Override

public Date deserialize(JsonParser p, DeserializationContext ctxt) throws IOException,

JsonProcessingException {

String value = p.getValueAsString();

if (StringUtils.isEmpty(value)) {

return null;

}

try {

ISO8601DateFormat formatter = new ISO8601DateFormat();

formatter.setTimeZone(UTC);

return formatter.parse(value.trim());

} catch (ParseException ex) {

LOG.error("deserialize: An exception occurred", ex);

throw new JsonMappingException("Unable to parse value [" + value

+ "] as a ISO8601 date", ex);

}

}

}

• Custom Serializer :

package com.custom;

import java.io.IOException;

import java.util.Date;

import java.util.TimeZone;

import com.fasterxml.jackson.core.JsonGenerator;

import com.fasterxml.jackson.core.JsonProcessingException;

import com.fasterxml.jackson.databind.JsonSerializer;

import com.fasterxml.jackson.databind.SerializerProvider;

import com.fasterxml.jackson.databind.util.ISO8601DateFormat;

/**

 * JSON Serializer to output dates in ISO-8601 standard date/time format.

 *

 * @author Sanjay Ingole

 */

public class DateTimeJsonSerializer extends JsonSerializer<Date> {

/** UTC (GMT) timezone. */

private static final TimeZone UTC = TimeZone.getTimeZone("UTC");

/**

* Constructor.

*/

public DateTimeJsonSerializer() {

super();

}

@Override

public void serialize(Date value, JsonGenerator gen, SerializerProvider serializers)

throws IOException, JsonProcessingException {

String formattedDate;

if (value == null) {

formattedDate = "";

} else {

ISO8601DateFormat formatter = new ISO8601DateFormat();

formatter.setTimeZone(UTC);

formattedDate = formatter.format(value);

}

gen.writeString(formattedDate);

}

}