java - com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of TestAcceptanceCriteria out of START_ARRAY token -

given following json file:

 [       {"name":"test_12345_54321",               "acceptancecriteria":                   [                     {                       "given":"i developer",                       "and":"i have test case write",                       "when":"i run test",                       "then":"i report generated details."                     }                   ]        },        {"name":"test_2",                "acceptancecriteria":                    [                      {                       "given":"i developer test 2",                       "and":"i have test case write test 2",                       "when":"i run test test 2",                       "then":"i report generated details.2"                      }                    ]         }     ] 

i trying access values within json file using jackson object mapper. follows:

file jsonfile = new file("results/acceptancecriteria.json");          objectmapper mapper = new objectmapper();         testacceptancecriteria acceptancecriteria = null;         acceptancecriteria = mapper.readvalue(jsonfile, testacceptancecriteria.class);         system.out.println(acceptancecriteria.getacceptancecriteria()); 

each time try access variable following error:

com.fasterxml.jackson.databind.jsonmappingexception: can not deserialize instance of file.readers.testacceptancecriteria out of start_array token @ [source: results\acceptancecriteria.json; line: 1, column: 1] @ com.fasterxml.jackson.databind.jsonmappingexception.from(jsonmappingexception.java:270) @ com.fasterxml.jackson.databind.deserializationcontext.reportmappingexception(deserializationcontext.java:1234) @ com.fasterxml.jackson.databind.deserializationcontext.handleunexpectedtoken(deserializationcontext.java:1122) @ com.fasterxml.jackson.databind.deserializationcontext.handleunexpectedtoken(deserializationcontext.java:1075) @ com.fasterxml.jackson.databind.deser.beandeserializerbase.deserializefromarray(beandeserializerbase.java:1374) @ com.fasterxml.jackson.databind.deser.beandeserializer._deserializeother(beandeserializer.java:174) @ com.fasterxml.jackson.databind.deser.beandeserializer.deserialize(beandeserializer.java:150) @ com.fasterxml.jackson.databind.objectmapper._readmapandclose(objectmapper.java:3798) @ com.fasterxml.jackson.databind.objectmapper.readvalue(objectmapper.java:2740) @ file.readers.acceptancecriteriajsonreader.main(acceptancecriteriajsonreader.java:51)

my classes follows:

 public class acceptancecriteria{     private string given;     private string and;     private string when;     private string then;      public string getgiven(){         return given;     }     public void setgiven(string given){         this.given = given;     }     public string getand(){         return and;     }     public void setand(string and){         this.and = and;     }     public string getwhen(){         return when;     }     public void setwhen(string when){         this.when = when;     }     public string getthen(){         return then;     }     public void setthen(string then){         this.then = then;     } } 

...

    import java.util.list;     public class testacceptancecriteria {     private string name;     private list<acceptancecriteria> acceptancecriteria;      public string getname(){         return name;     }     public void setname(string name){         this.name = name;     }     public list<acceptancecriteria> getacceptancecriteria(){         return acceptancecriteria;     }     public void setacceptancecriteria(list<acceptancecriteria> acceptancecriteria){         this.acceptancecriteria = acceptancecriteria;     } } 

you trying deserialize array of entities single object, cause problem. let's try:

list<testacceptancecriteria> acceptancecriteria = null; acceptancecriteria = mapper.readvalue(json, new typereference<list<testacceptancecriteria>>(){});