How do I inject collections properties in Spring?

Beside injecting a simple value (using the value attribute) and a reference to other bean (using the ref attribute). We can also inject collections properties into a bean.

Spring provides four ways to inject collections. There are <list> and <set> that can be used to inject arrays or any implementation of java.util.Collection. The <map> that can be used to inject property of type java.util.Map. And the <props> can be used to inject property of type java.util.Properties.

Here is a table that summarize the collection configuration support in Spring.

Collection Element Description
<list> Wiring a list of values, where the values might have duplicates.
<set> Wiring a set of values, where the values can not have duplicates.
<map> Wiring a key-value pairs collection, where the key and value can be any type
<props> Wiring a key-value pairs property, where the key and value are both type of String

You can see the following example on how to use each type of this collection configuration:

Wayan Saryada

Wayan Saryada

A programmer, runner, recreational diver, currently living in the island of Bali, Indonesia. Mostly programming in Java, creating web based application with Spring Framework, JPA, etc. If you need help on Java programming you can hire me on Fiverr.
Wayan Saryada

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