Jackson-动态抑制属性的序列化（写入）

Question

I am trying to convert java object to JSON object in Tomcat/jersey using Jackson. And want to suppress serialization(write) of certain properties dynamically.

I can use JsonIgnore, but I want to make the ignore decision at runtime. Any ideas??

So as an example below, I want to suppress "id" field when i serialize the User object to JSON..

new ObjectMapper.writeValueAsString(user);


class User {

private String id = null;
private String firstName = null;
private String lastName = null;

//getters
//setters

}//end class

Answer 1

Yes, JSON View is the way to go.

If you eg need to let the client to decide which fields to marshal, this example might help: http://svn.codehaus.org/jackson/tags/1.6/1.6.3/src/sample/CustomSerializationView.java

Answer 2

Check

ObjectMapper.configure(SerialiationJson.Feature f, boolean value)

and

org.codehaus.jackson.annotate.JsonIgnore 

annotation

This will work only when you want all instances of a certain type to ignore id on serialization. If you truly want dynamic (aka per instance customization) you will probabily have to hack the jackson library yourself.

Answer 3

I don't see any way of doing that. If you need to dynamically decide which properties are marshalled, then I suggest you manually construct a Map of keys to values for your objects, and then pass that Map to Jackson, rather than passing the User object directly.

Answer 4

Have you tried using JSON Views ? Views allow annotation-based mechanism for defining different profiles, so if you just need slightly differing views for different users, this could work for you.