Convert Java Object to Map

You can use ObjectMapper.convertValue to convert a java object to a java map.

The convertValue method in the ObjectMapper class allows you to convert a Java object of one type to another type, without the need for explicit serialization and deserialization steps.

This method takes two parameters: the source object and the target type (specified as a JavaType or TypeReference).

Let’s consider a simple example to demonstrate the usage of convertValue. Suppose we have a Person class, and we want to convert an instance of Person to a Map<String, Object> representation:

Ignoring Null Fields with @JsonInclude

The @JsonInclude annotation is used to specify whether fields with null values should be included in the JSON output. By applying this annotation to fields or at the class level, we can control how Jackson handles null fields during serialization.

Control the Field Order in Serialized JSON Using @JsonPropertyOrder

Jackson provides a @JsonPropertyOrder annotation to specify the order of fields(possibly partial) on serialization. Fields included in annotation declaration will be serialized first in defined order, followed by any fields not included in the definition. This is very helpful when you want to ensure that some fields are output before other fields

Customize Serialization Output with @JsonValue

The @JsonValue annotation is used to indicate that a method in a class should be used for serialization. When you apply this annotation to a method, Jackson will invoke that method to determine how the object should be represented in the JSON output.

Change Field Names with @JsonProperty

In this article, we’ll delve into the versatility of Jackson’s @JsonProperty annotation, which allows you to customize field names during both serialization and deserialization.

Preventing Class Serialization with @JsonIgnoreType

In this article, we’ll dive into an advanced Jackson annotation, @JsonIgnoreType, which allows you to exclude an entire class from being serialized when it’s used as a field within another class. Additionally, we’ll explore other techniques to prevent class serialization in Java.