How to Map Collections Using Dozer in Java

How do I map collections in Dozer?

Dozer is a powerful Java Bean to Java Bean mapper that simplifies the process of converting one object into another. Mapping collections in Dozer allows you to efficiently transform lists, sets, or other collection types from one data structure to another, preserving their contents. In this guide, I will explain how to configure and utilize Dozer for mapping collections effectively.

<mapping>
    <class-a>com.example.SourceClass</class-a>
    <class-b>com.example.TargetClass</class-b>
    <field>
        <a>sourceList</a>
        <b>targetList</b>
    </field>
</mapping> 

// Java classes example
public class SourceClass {
    private List<String> sourceList;
    // getters and setters
}

public class TargetClass {
    private List<String> targetList;
    // getters and setters
}

Causes

• Misconfiguration of Dozer mapping files.
• Incorrect collection types specified in the mapping configuration.
• Failure to include necessary dependencies for Dozer.

Solutions

• Ensure the Dozer mapping XML file is configured correctly to support collection types.
• Use the correct Dozer Collection mapping types such as 'list', 'set', and 'array'.
• Verify that all required Dozer dependencies are included in your project.

Mistake: Not defining the collection type in the mapping file.

Solution: Always specify the collection type in the Dozer mapping. Check your XML definitions.

Mistake: Assuming Dozer can handle collection mapping without configuration.

Solution: Review and define all necessary mappings for collections in your Dozer configuration.