Sometimes we need to convert from Java Properties to a Java Object or vise versa. JavaPropsMapper from Jackson library class provides an easy way to do the conversion.

A BiMap is useful in scenarios where you need to look up data in both directions.

For example, if you have a mapping between employee IDs and names, and you want to quickly retrieve an employee’s ID based on their name or vice versa, a BiMap can provide this functionality.

Guava provides an implementation of the BiMap interface called HashBiMap. Let’s see you can use it.

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:

In this article, let’s find the various ways to get the number of occurrences of elements in a Java List.

The Multiset class in Google’s Guava library provides a powerful data structure that extends the capabilities of a traditional Set by allowing multiple occurrences of the same element. This makes Multiset particularly useful for counting elements and solving problems where element frequency matters.

The Stopwatch class in Google’s Guava library is a powerful utility for measuring elapsed time in our applications. It simplifies the process of tracking how long operations take, which can be useful for performance monitoring, debugging, and optimization.

In this article, we’ll delve into the usage of SimpleBeanPropertyFilter in Jackson, a feature that allows you to filter and control the properties included in the JSON output during serialization. This filter provides fine-grained control over which properties are included, making it useful for customizing your JSON output.

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.

The @JsonAlias annotation is used to specify alternate names for properties during deserialization. This allows us to map properties from JSON data to corresponding fields in our Java class, even if the property names don’t match exactly.

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