How can I force Jackson to write numbers as strings when serializing my objects

Question

I have an id that is pretty large on one of my java objects. When it jackson converts it to JSON it sends it down as a number (e.g. {"id":1000110040000000001}) but as soon as it becomes a javascript object the id gets changed to 1000110040000000000. I read about this issue here

It works fine when the id is smaller. My first thought is to just force Jackson to convert all the numbers to strings but I am open to other options as well. If possible I would prefer not to add Jackson annotations to my java objects.

Answer 1

Jackson-databind (at least 2.1.3) provides special ToStringSerializer. That did it for me.

@Id @JsonSerialize(using = ToStringSerializer.class)
private Long id;

Answer 2

com.fasterxml.jackson.core:jackson-core:2.5.4 provides JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS for ObjectMapper configuration.

final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS, true);

Foo foo = new Foo(10);
System.out.println("Output: " + objectMapper.writeValueAsString(foo));

Output: {"a":"1"}

class Foo {
    @XmlElement(name = "a")
    Integer a
}

To include the dependency:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.7.2</version>
</dependency>