Add annotation for ignoring unknown properties (@JsonIgnoreProperties?)

One additional use case: this could also be used to prevent binding of sub-trees that are not useful. If such property/-ies are defined using this method, such sub-trees are skipped without binding. This is more efficient than having a dummy set method that ignores its argument.

Thinking bit more about this, I think this can be implemented with just 2 pieces:

1. Add a DeserializationConfig.Feature that will set default handling of unknown properties; (error or ignore), to be used if other methods fails (i.e. for properties that match no other processing)
2. Make @JsonIgnoreProperties take a class that implements interface (IgnorableFilter or whatever), to be used for determining handling of unknown properties (and perhaps couple of standard implementations)

Latter would allow any kind of handling, provided it takes enough information (parser, context; perhaps Bean instance property logically belongs to).

One potential problem: what to do with "deferred" deserialization; that is, cases where bean instantiation occurs after encountering such properties (can happen with non-default constructors (new 1.2 feature) at least).

Given time constraints, I will split this request into 2 issues: one (this one) will deal with annotation(s) to add; and another one (which I will create) that only deals with the global default handling.
Only latter will be implemented for 1.2; annotation will be added to 1.3 so that there is little bit more to hash out details so that the new feature will work well, cover enough use cases, and is consistent with rest of API.

Created JACKSON-147 to cover the global default setting for error reporting.

Will implement a simple solution; annotation (@JsonIgnoreProperties) with just two choices – explicit list of ignorable properties, or "ignore any unknown". But it will apply to both serialization (explicit list) and deserialization (explicit, ignore-unknown).
And finally, if a non-annotation method is desired in future, it can be added based on same internal mechanism.

Implemented

does it support custom annotation?

public class User{
...
@DontIncludeMe
private String getPassword(){ return password; } }

Not by default.
But you could implement support by defining your own AnnotationIntrospector implementation, which overrides methods that are used to find annotation settings. There is a base implementation (NopAnnotationIntrospector) that has dummy implementations for all methods, so you could extend that, just override 2 methods you need.

thanks,I have override JacksonAnnotationIntrospector,actually 3 methods,isHandled(Annotation) must return true

private static ObjectMapper objectMapper = new ObjectMapper()
.setSerializationConfig(new SerializationConfig(
new BasicClassIntrospector(),
new JacksonAnnotationIntrospector() {
public boolean isHandled(Annotation ann) { return true; }

@Override
public boolean isIgnorableField(AnnotatedField f) { return super.isIgnorableField(f) || isIgnorable(f); }

@Override
public boolean isIgnorableMethod(AnnotatedMethod m) { return super.isIgnorableMethod(m) || isIgnorable(m); }

private boolean isIgnorable(Annotated a) { return (a.getAnnotation(NotInJson.class) != null || a .getAnnotation(NotInCopy.class) != null); }
}));

BTW: how to assign serializedName like @SerializedName in google-gson

@SerializedName("outline-colour")// because '-' is not allowed in java syntax
private String outlineColour;

I will move from gson to jackson, hope jackson can handle this.

Ok good. Yes, forgot to mention that isHandled() needs to be implemented; it's ok to just return true, although the idea is to return true just for annotations that your code handles. But that's just an optimization (to ignore annotations used for other purposes).

Naming of JSON properties (fields, methods) can be done using @JsonProperty annotation. That will also serve to indicate serializable/deserializable fields.
Or if you want to customize that, there are separate methods in AnnotationIntrospector.

I hope things work out!

Btw; feel free to send these questions on user or dev lists – that way other users can also suggest ways to do things as well as learn new techniques.

Included in 1.4.0 release.