The Techno Journals

It's very common to have the DTO class for a given entity in any application. When persisting data, we use entity objects and when we need to provide the data to end user/application we use DTO class. Due to this we may need to have similar properties on DTO class as we have in our Entity class and to share the data we populate DTO objects using entity objects. To do this we may need to call getter on entity and then setter on DTO for the same data which increases number of code line. Also if number of DTOs are high then we need to write lot of code to just get and set the values or vice-versa. To overcome this problem we are going to use Jackson API and will see how to do it with minimal code only. Maven dependency <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.9</version> </dependency> Entity class Below is ...

Sometimes, we may need to convert the java objet to key-value pairs, for example Map or Properties class. It can be doable in multiple ways like using reflection or jackson library. We are going to use jackson library to achieve it here. Maven dependency <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.9</version> </dependency> Employee.java We will use this class to convert to map and properties class. class Employee{ private long id; private String name; private Integer age; public Employee(long id, String name, Integer age) { super(); this.id = id; this.name = name; this.age = age; } //getter methods //setter methods } Generic method to convert the object Jackson library provides ObjectMapper class which provides "convertValue" method to convert the java objects. Below is the co...