Jackson @JsonProperty(required=true) doesn't throw an exception

Question

I am using jackson 2.2 annotation @JsonProperty with required set to true. While deserializing json file which doesn't contain that property via ObjectMapper readValue() method no exception is being thrown. Is it supposed to work in a different way or did I missed something?

My dto class:

public class User {     public enum Gender {MALE, FEMALE}      ;      public static class Name {         private String _first, _last;          public String getFirst() {             return _first;         }          public String getLast() {             return _last;         }          public void setFirst(String s) {             _first = s;         }          public void setLast(String s) {             _last = s;         }     }      private Gender _gender;     private Name _name;     private boolean _isVerified;     private byte[] _userImage;      @JsonProperty(value ="NAAME",required = true)     public Name getName() {         return _name;     }      @JsonProperty("VERIFIED")     public boolean isVerified() {         return _isVerified;     }      @JsonProperty("GENDER")     public Gender getGender() {         return _gender;     }     @JsonProperty("IMG")     public byte[] getUserImage() {         return _userImage;     }      @JsonProperty(value ="NAAME",required = true)     public void setName(Name n) {         _name = n;     }     @JsonProperty("VERIFIED")     public void setVerified(boolean b) {         _isVerified = b;     }     @JsonProperty("GENDER")     public void setGender(Gender g) {         _gender = g;     }     @JsonProperty("IMG")     public void setUserImage(byte[] b) {         _userImage = b;     } } 

This is how do I deserialize the class:

public class Serializer {     private ObjectMapper mapper;      public Serializer() {         mapper = new ObjectMapper();         SimpleModule sm = new SimpleModule("PIF deserialization");         mapper.registerModule(sm);     }      public void writeUser(File filename, User user) throws IOException {         mapper.writeValue(filename, user);     }      public User readUser(File filename) throws IOException {           return mapper.readValue(filename, User.class);       } } 

This is how it is actually called:

    Serializer serializer = new Serializer();     User result = serializer.readUser(new File("user.json")); 

Actuall json looks like:

{"GENDER":"FEMALE","VERIFIED":true,"IMG":"AQ8="} 

I would expect that since _name is not specified in json file and is required that the exception will be thrown.

Answer 1

With Jackson 2.6 you can use required, however you have to do it using JsonCreator

For example:

public class MyClass {      @JsonCreator     public MyClass(@JsonProperty(value = "x", required = true) Integer x, @JsonProperty(value = "value_y", required = true) Integer y) {         this.x = x;         this.y = y;     }      private Integer x;     private Integer y; } 

If x or y are not present an exception will be thrown when trying to deserialize it.

Answer 2

As per Jackson annotations javadocs: "Note that as of 2.0, this property is NOT used by BeanDeserializer: support is expected to be added for a later minor version."

That is: no validation is performed using this settings. It is only (currently) used for generating JSON Schema, or by custom code.