java - Jackson + Builder Pattern?

Question

I'd like Jackson to deserialize a class with the following constructor:

public Clinic(String name, Address address)

Deserializing the first argument is easy. The problem is that Address is defined as:

public class Address {
  private Address(Map<LocationType, String> components)
  ...

  public static class Builder {
    public Builder setCity(String value);
    public Builder setCountry(String value);
    public Address create();
  }
}

and is constructed like this: new Address.Builder().setCity("foo").setCountry("bar").create();

Is there a way to get key-value pairs from Jackson in order to construct the Address myself? Alternatively, is there a way to get Jackson to use the Builder class itself?

Answer 1

As long as you are using Jackson 2+, then there is now built in support for this.

First you need to add this annotation to your Address class:

@JsonDeserialize(builder = Address.Builder.class)

Then you need to add this annotation to your Builder class:

@JsonPOJOBuilder(buildMethodName = "create", withPrefix = "set")

You can skip this second annotation if you are happy to rename your Builder's create method to build, and your Builder's setters to be prefixed to with, instead of set.

Full example:

@JsonDeserialize(builder = Address.Builder.class)
public class Address
{
  private Address(Map<LocationType, String> components)
  ...

  @JsonPOJOBuilder(buildMethodName = "create", withPrefix = "set")
  public static class Builder
  {
    public Builder setCity(String value);
    public Builder setCountry(String value);
    public Address create();
  }
}