I'm trying to learn the process of packaging. While using the Jackson ObjectMapper to parse my JSON file, I receive an UnrecognizedPropertyException.
com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "usa" (class com.stateparser.database.StateGroup), not marked as ignorable (one known property: "states"])
at [Source: (File); line: 2, column: 11] (through reference chain: com.stateparser.database.StateGroup["usa"])
at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:61)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:1127)
at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1989)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1700)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownVanilla(BeanDeserializerBase.java:1678)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:319)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:176)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:322)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4674)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3494)
at com.stateparser.Main.main(Main.java:20)
I'm not sure where I created the error. I was attempting to create a list of state objects. With the list of object, loop through it and print the data for each object to the console.
Following the accepted answer of a previous question asked
Jackson ObjectMapper JSON to Java Object RETURNS NULL Values
and the process of packaging by layer; I have laid out my project as follows:
The JSON file which contains the list of States:
{
"usa": [
{
"abbr": "AL",
"name": "Alabama",
"capital": "Montgomery",
"latitude": "32.361538",
"longitude": "-86.279118"
},
{
"abbr": "AK",
"name": "Alaska",
"capital": "Juneau",
"latitude": "58.301935",
"longitude": "-134.419740"
},
{
"abbr": "AZ",
"name": "Arizona",
"capital": "Phoenix",
"latitude": "33.448457",
"longitude": "-112.073844"
},
{
"abbr": "AR",
"name": "Arkansas",
"capital": "Little Rock",
"latitude": "34.736009",
"longitude": "-92.331122"
},
{
"abbr": "CA",
"name": "California",
"capital": "Sacramento",
"latitude": "38.555605",
"longitude": "-121.468926"
},
{
"abbr": "CO",
"name": "Colorado",
"capital": "Denver",
"latitude": "39.7391667",
"longitude": "-104.984167"
},
{
"abbr": "CT",
"name": "Connecticut",
"capital": "Hartford",
"latitude": "41.767",
"longitude": "-72.677"
},
{
"abbr": "DE",
"name": "Delaware",
"capital": "Dover",
"latitude": "39.161921",
"longitude": "-75.526755"
},
{
"abbr": "FL",
"name": "Florida",
"capital": "Tallahassee",
"latitude": "30.4518",
"longitude": "-84.27277"
},
{
"abbr": "GA",
"name": "Georgia",
"capital": "Atlanta",
"latitude": "33.76",
"longitude": "-84.39"
},
{
"abbr": "HI",
"name": "Hawaii",
"capital": "Honolulu",
"latitude": "21.30895",
"longitude": "-157.826182"
},
{
"abbr": "ID",
"name": "Idaho",
"capital": "Boise",
"latitude": "43.613739",
"longitude": "-116.237651"
},
{
"abbr": "IL",
"name": "Illinois",
"capital": "Springfield",
"latitude": "39.783250",
"longitude": "-89.650373"
},
{
"abbr": "IN",
"name": "Indiana",
"capital": "Indianapolis",
"latitude": "39.790942",
"longitude": "-86.147685"
},
{
"abbr": "IA",
"name": "Iowa",
"capital": "Des Moines",
"latitude": "41.590939",
"longitude": "-93.620866"
},
{
"abbr": "KS",
"name": "Kansas",
"capital": "Topeka",
"latitude": "39.04",
"longitude": "-95.69"
},
{
"abbr": "KY",
"name": "Kentucky",
"capital": "Frankfort",
"latitude": "38.197274",
"longitude": "-84.86311"
},
{
"abbr": "LA",
"name": "Louisiana",
"capital": "Baton Rouge",
"latitude": "30.45809",
"longitude": "-91.140229"
},
{
"abbr": "ME",
"name": "Maine",
"capital": "Augusta",
"latitude": "44.323535",
"longitude": "-69.765261"
},
{
"abbr": "MD",
"name": "Maryland",
"capital": "Annapolis",
"latitude": "38.972945",
"longitude": "-76.501157"
},
{
"abbr": "MA",
"name": "Massachusetts",
"capital": "Boston",
"latitude": "42.2352",
"longitude": "-71.0275"
},
{
"abbr": "MI",
"name": "Michigan",
"capital": "Lansing",
"latitude": "42.7335",
"longitude": "-84.5467"
},
{
"abbr": "MN",
"name": "Minnesota",
"capital": "Saint Paul",
"latitude": "44.95",
"longitude": "-93.094"
},
{
"abbr": "MS",
"name": "Mississippi",
"capital": "Jackson",
"latitude": "32.320",
"longitude": "-90.207"
},
{
"abbr": "MO",
"name": "Missouri",
"capital": "Jefferson City",
"latitude": "38.572954",
"longitude": "-92.189283"
},
{
"abbr": "MT",
"name": "Montana",
"capital": "Helana",
"latitude": "46.595805",
"longitude": "-112.027031"
},
{
"abbr": "NE",
"name": "Nebraska",
"capital": "Lincoln",
"latitude": "40.809868",
"longitude": "-96.675345"
},
{
"abbr": "NV",
"name": "Nevada",
"capital": "Carson City",
"latitude": "39.160949",
"longitude": "-119.753877"
},
{
"abbr": "NH",
"name": "New Hampshire",
"capital": "Concord",
"latitude": "43.220093",
"longitude": "-71.549127"
},
{
"abbr": "NJ",
"name": "New Jersey",
"capital": "Trenton",
"latitude": "40.221741",
"longitude": "-74.756138"
},
{
"abbr": "NM",
"name": "New Mexico",
"capital": "Santa Fe",
"latitude": "35.667231",
"longitude": "-105.964575"
},
{
"abbr": "NY",
"name": "New York",
"capital": "Albany",
"latitude": "42.659829",
"longitude": "-73.781339"
},
{
"abbr": "NC",
"name": "North Carolina",
"capital": "Raleigh",
"latitude": "35.771",
"longitude": "-78.638"
},
{
"abbr": "ND",
"name": "North Dakota",
"capital": "Bismarck",
"latitude": "48.813343",
"longitude": "-100.779004"
},
{
"abbr": "OH",
"name": "Ohio",
"capital": "Columbus",
"latitude": "39.962245",
"longitude": "-83.000647"
},
{
"abbr": "OK",
"name": "Oklahoma",
"capital": "Oklahoma City",
"latitude": "35.482309",
"longitude": "-97.534994"
},
{
"abbr": "OR",
"name": "Oregon",
"capital": "Salem",
"latitude": "44.931109",
"longitude": "-123.029159"
},
{
"abbr": "PA",
"name": "Pennsylvania",
"capital": "Harrisburg",
"latitude": "40.269789",
"longitude": "-76.875613"
},
{
"abbr": "RI",
"name": "Rhode Island",
"capital": "Providence",
"latitude": "41.82355",
"longitude": "-71.422132"
},
{
"abbr": "SC",
"name": "South Carolina",
"capital": "Columbia",
"latitude": "34.000",
"longitude": "-81.035"
},
{
"abbr": "SD",
"name": "South Dakota",
"capital": "Pierre",
"latitude": "44.367966",
"longitude": "-100.336378"
},
{
"abbr": "TN",
"name": "Tennessee",
"capital": "Nashville",
"latitude": "36.165",
"longitude": "-86.784"
},
{
"abbr": "TX",
"name": "Texas",
"capital": "Austin",
"latitude": "30.266667",
"longitude": "-97.75"
},
{
"abbr": "UT",
"name": "Utah",
"capital": "Salt Lake City",
"latitude": "40.7547",
"longitude": "-111.892622"
},
{
"abbr": "VT",
"name": "Vermont",
"capital": "Montpelier",
"latitude": "44.26639",
"longitude": "-72.57194"
},
{
"abbr": "VA",
"name": "Virginia",
"capital": "Richmond",
"latitude": "37.54",
"longitude": "-77.46"
},
{
"abbr": "WA",
"name": "Washington",
"capital": "Olympia",
"latitude": "47.042418",
"longitude": "-122.893077"
},
{
"abbr": "WV",
"name": "West Virginia",
"capital": "Charleston",
"latitude": "38.349497",
"longitude": "-81.633294"
},
{
"abbr": "WI",
"name": "Wisconsin",
"capital": "Madison",
"latitude": "43.074722",
"longitude": "-89.384444"
},
{
"abbr": "WY",
"name": "Wyoming",
"capital": "Cheyenne",
"latitude": "41.145548",
"longitude": "-104.802042"
}
]
}
The Java class file which describes a state:
package com.stateparser.database;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class State {
private String abbr;
private String name;
private String capital;
private String latitude;
private String longitude;
public State() {
// DEFAULT CONSTRUCTOR
}
public State(String abbr, String name, String capital, String latitude, String longitude) {
this.abbr = abbr;
this.name = name;
this.capital = capital;
this.latitude = latitude;
this.longitude = longitude;
}
@Override
public String toString() {
return name + "{" +
"name='" + name + "'" +
"capital='" + capital + "'" +
"abbr='" + abbr + "'" +
"latitude='" + latitude + "'" +
"longitude='" + longitude + "'}";
}
public String getAbbr() {
return abbr;
}
public void setAbbr(String abbr) {
this.abbr = abbr;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCapital() {
return capital;
}
public void setCapital(String capital) {
this.capital = capital;
}
public String getLatitude() {
return latitude;
}
public void setLatitude(String latitude) {
this.latitude = latitude;
}
public String getLongitude() {
return longitude;
}
public void setLongitude(String longitude) {
this.longitude = longitude;
}
}
The Java class which creates a list of objects based on my state class:
package com.stateparser.database;
import java.util.List;
public class StateGroup {
private List<State> states;
public List<State> getStates() {
return states;
}
public void setStates(List<State> states) {
this.states = states;
}
}
The main Java class:
package com.stateparser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.stateparser.database.State;
import com.stateparser.database.StateGroup;
import java.io.File;
import java.io.IOException;
import java.util.List;
public class Main {
public static void main(String[] args) {
File file = new File("src/main/resources/States.json");
ObjectMapper mapper = new ObjectMapper();
try {
StateGroup States = mapper.readValue(file, StateGroup.class);
List<State> allTerritories = States.getStates();
allTerritories.forEach(states -> {
System.out.println(states);
});
} catch (JsonProcessingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
I'm looking for some help to understand why I receive the UnrecognizedPropertyException.
