【异常】JSON解析错误提示JSON parse error: Cannot deserialize value of type java.lang.String from Object value

一、异常内容

JSON parse error: 
Cannot deserialize value of type java.lang.String from Object value (token JsonToken.START_OBJECT); 
nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: 
Cannot deserialize value of type java.lang.String from Object value (token JsonToken.START_OBJECT)
 at [Source: (org.springframework.util.StreamUtils$NonClosingInputStream); line: 1, column: