No content to map due to end-of-input jackson parser

Question

I am getting this response from the server {\"status\":\"true\",\"msg\":\"success\"}

I am trying to parse this json string using Jackson parser library

Answer 1

I could fix this error. In my case, the problem was at client side. By mistake I did not close the stream that I was writing to server. I closed stream and it worked fine. Even the error sounds like server was not able to identify the end-of-input.

OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
out.write(jsonstring.getBytes());
out.close() ; //This is what I did

Answer 2

A simple fix could be Content-Type: application/json

You are probably making a REST API call to get the response.

Mostly you are not setting Content-Type: application/json when you the request. Content-Type: application/x-www-form-urlencoded will be chosen which might be causing this exception.

Answer 3

In my case the problem was caused by my passing a null InputStream to the ObjectMapper.readValue call:

ObjectMapper objectMapper = ...
InputStream is = null; // The code here was returning null.
Foo foo = objectMapper.readValue(is, Foo.class)

I am guessing that this is the most common reason for this exception.

Answer 4

import com.fasterxml.jackson.core.JsonParser.Feature;
import com.fasterxml.jackson.databind.ObjectMapper;

StatusResponses loginValidator = null;

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(Feature.AUTO_CLOSE_SOURCE, true);

try {
    String res = result.getResponseAsString();//{"status":"true","msg":"success"}
    loginValidator = objectMapper.readValue(res, StatusResponses.class);//replaced result.getResponseAsString() with res
} catch (Exception e) {
    e.printStackTrace();
}

Don't know how it worked and why it worked? :( but it worked

Answer 5

For one, @JsonProperty("status") and @JsonProperty("msg") should only be there only when declaring the fields, not on the setters and geters.

In fact, the simplest way to parse this would be

@JsonAutoDetect  //if you don't want to have getters and setters for each JsonProperty
public class StatusResponses {

   @JsonProperty("status")
   private String status;

   @JsonProperty("msg")
   private String message;

}

Answer 6

In my case I was reading the stream in a jersey RequestEventListener I created on the server side to log the request body prior to the request being processed. I then realized that this probably resulted in the subsequent read to yield no string (which is what is passed over when the business logic is run). I verified that to be the case.

So if you are using streams to read the JSON string be careful of that.