Filter nested objects using Jackson's BeanPropertyFilter - jackson

Question

I have the following objects:
#JsonFilter("myFilter")
public class Person {
private Name name;
private int age;
public Name getName() {return name;}
public void setName(Name name) {this.name = name;}
public int getAge() {return age;}
public void setAge(int age) {this.age = age;}
}
#JsonFilter("myFilter")
public class Name {
private String firstName;
private String lastName;
public String getFirstName() {return firstName;}
public void setFirstName(String firstName) {this.firstName = firstName;}
public String getLastName() {return lastName;}
public void setLastName(String lastName) {this.lastName = lastName;}
}
I wrote a method to marshall a Person object like this:
#Test
public void test() throws Exception {
Person person = new Person();
person.setAge(10);
Name name = new Name();
name.setFirstName("fname");
name.setLastName("lastname");
person.setName(name);
ObjectMapper mapper = new ObjectMapper();
FilterProvider filters = new SimpleFilterProvider().addFilter("myFilter",
SimpleBeanPropertyFilter.filterOutAllExcept("name.firstName"));
System.out.println(mapper.filteredWriter(filters).writeValueAsString(person));
}
What I'd like to see is JSON like this:
{"name":{"firstName":"fname"}}
Is something like that possible?

Answer 1

Ok, figured it out. Varargs would have made this a bit prettier, but oh well. Just hope I don't have two inner beans which have properties with the same name. I wouldn't be able to make the distinction between the two
FilterProvider filters = new SimpleFilterProvider()
.addFilter("myFilter", SimpleBeanPropertyFilter
.filterOutAllExcept(new HashSet<String>(Arrays
.asList(new String[] { "name", "firstName" }))));

Answer 2

There's a better way that solves problem with property name conflicts. Just add another filter to class Name ("nameFilter"):
#JsonFilter("personFilter")
public class Person {
private Name name;
private int age;
public Name getName() {return name;}
public void setName(Name name) {this.name = name;}
public int getAge() {return age;}
public void setAge(int age) {this.age = age;}
}
#JsonFilter("nameFilter")
public class Name {
private String firstName;
private String lastName;
public String getFirstName() {return firstName;}
public void setFirstName(String firstName) {this.firstName = firstName;}
public String getLastName() {return lastName;}
public void setLastName(String lastName) {this.lastName = lastName;}
}
And then add 2 filters, one for Person and one for Name:
FilterProvider filterProvider = new SimpleFilterProvider()
.addFilter("personFilter", SimpleBeanPropertyFilter.filterOutAllExcept("name"))
.addFilter("nameFilter", SimpleBeanPropertyFilter.filterOutAllExcept("firstName"));