org.codehaus.jackson.map.JsonMappingException: No suitable constructor found for type

org.codehaus.jackson.map.JsonMappingException: No suitable constructor found for type

 

org.codehaus.jackson.map.JsonMappingException: No suitable constructor found  for type [simple type,  class test.jackson.Employee]: can not instantiate from JSON object (need to add/enable type information?)
 at [Source: c:\temp\employee.json; line:  1 , column:  2 ]
    at org.codehaus.jackson.map.JsonMappingException.from(JsonMappingException.java: 163 )
    at org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java: 483 )
    at org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java: 350 )
    at org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java: 2395 )
    at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java: 1549 )
    at test.jackson.JSONToJavaExample.main(JSONToJavaExample.java: 19 )

一般来说，解决上面问题从下面几个方面入手：

1、是否缺少默认构造函数

2、是否是类的访问修饰符问题，即jackson访问不到。