jackson - JSON Invalid UTF-8 middle byte

Question

This error happens when the (Jackson, this case) JSON engine tries to parse some JSON that is not encoded in UTF-8.

How to tell the engine that it should expect something different from UTF-8, such as UTF-16?

HttpHeaders requestHeaders = createSomeHeader();
RestTemplate restTemplate = new RestTemplate();
HttpEntity<?> requestEntity = new HttpEntity<Object>(requestHeaders);
String url = "someurl"
ResponseEntity<MyObject[]> arrayResponseEntity = restTemplate.exchange(url, HttpMethod.GET, requestEntity, MyObject[].class);

error log:

Caused by: org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Invalid UTF-8 middle byte 0x20
at [Source: org.apache.http.conn.EofSensorInputStream@44d397b0; line: 92, column: 42]; nested exception is org.codehaus.jackson.JsonParseException: Invalid UTF-8 middle byte 0x20
at [Source: org.apache.http.conn.EofSensorInputStream@44d397b0; line: 92, column: 42]
at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.readInternal(MappingJacksonHttpMessageConverter.java:138)
at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:154)
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:74)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:622)
at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:608)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:449)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:404)
at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:380)
... 4 more
Caused by: org.codehaus.jackson.JsonParseException: Invalid UTF-8 middle byte 0x20
at [Source: org.apache.http.conn.EofSensorInputStream@44d397b0; line: 92, column: 42]
at org.codehaus.jackson.JsonParser._constructError(JsonParser.java:1213)
at org.codehaus.jackson.impl.JsonParserMinimalBase._reportError(JsonParserMinimalBase.java:375)
at org.codehaus.jackson.impl.Utf8StreamParser._reportInvalidOther(Utf8StreamParser.java:2132)
at org.codehaus.jackson.impl.Utf8StreamParser._reportInvalidOther(Utf8StreamParser.java:2139)
at org.codehaus.jackson.impl.Utf8StreamParser._decodeUtf8_3fast(Utf8StreamParser.java:1962)

Answer 1

JSON data must be encoded as UTF-8, UTF-16 or UTF-32. The JSON decoder can determine the encoding by examining the first four octets of the byte stream:

       00 00 00 xx  UTF-32BE
       00 xx 00 xx  UTF-16BE
       xx 00 00 00  UTF-32LE
       xx 00 xx 00  UTF-16LE
       xx xx xx xx  UTF-8

It sounds like the server is encoding data in some illegal encoding (ISO-8859-1, windows-1252, etc.)