1. Overview

This quick tutorial illustrates how to change the name of a field to map to another JSON property on serialization.

If you want to dig deeper and learn other cool things you can do with the Jackson 2 – head on over to the main Jackson tutorial.

2. Change Name of Field for Serialization

Working with a simple entity:

public class MyDto { private String stringValue; public MyDto() { super(); } public String getStringValue() { return stringValue; } public void setStringValue(String stringValue) { this.stringValue = stringValue; } }

Serializing it will result in the following JSON:

{"stringValue":"some value"}

To customize that output so that, instead of stringValue we get – for example – strVal, we need to simply annotate the getter:

@JsonProperty("strVal") public String getStringValue() { return stringValue; }

Now, on serialization, we will get the desired output:

{"strVal":"some value"}

A simple unit test should verify the output is correct:

@Test public void givenNameOfFieldIsChanged_whenSerializing_thenCorrect() throws JsonParseException, IOException { ObjectMapper mapper = new ObjectMapper(); MyDtoFieldNameChanged dtoObject = new MyDtoFieldNameChanged(); dtoObject.setStringValue("a"); String dtoAsString = mapper.writeValueAsString(dtoObject); assertThat(dtoAsString, not(containsString("stringValue"))); assertThat(dtoAsString, containsString("strVal")); }

3. Conclusion

Marshaling an entity to adhere to a specific JSON format is a common task – and this article shows how to do is simply by using the @JsonProperty annotation.

The implementation of all these examples and code snippets can be found in my github project.