How to Inject Array of String using Spring dependency injection by constructor? | Spring Tutorial

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Introduction

When developing Spring applications, you frequently encounter requirements where a bean needs a collection or array of basic values such as strings. Spring makes it simple to inject arrays directly through the constructor.

In this guide, you will learn how to configure and inject a String Array (String[]) using constructor dependency injection in your Spring XML configuration.

1. Create the Java Bean Class

Create a class named FruitShop that has an array of strings (e.g., fruitsName) and a constructor to receive it:

import java.util.Arrays;

public class FruitShop {
    private String shopName;
    private String[] fruitsName;

    public FruitShop(String shopName, String[] fruitsName) {
        this.shopName = shopName;
        this.fruitsName = fruitsName;
    }

    public void displayFruitShopInfo() {
        System.out.println("Shop Name: " + shopName);
        System.out.println("Fruits: " + Arrays.toString(fruitsName));
    }
}
  

2. Configure Spring XML with <array>

In your Spring configuration file (applicationContext.xml), define the bean and pass the array elements using the <array> and <value> tags:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="fruitShop" class="FruitShop">
        <constructor-arg value="Daily Fresh Fruit Mart" />
        <constructor-arg>
            <array value-type="java.lang.String">
                <value>Apple</value>
                <value>Orange</value>
                <value>Banana</value>
                <value>Mango</value>
            </array>
        </constructor-arg>
    </bean>

</beans>
  

3. Load ApplicationContext and Execute

Finally, initialize the Spring container, fetch the configured bean, and invoke the method to verify the array injection:

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        FruitShop shop = (FruitShop) context.getBean("fruitShop");
        shop.displayFruitShopInfo();
    }
}
  

Watch More Spring Tutorials

• How to Inject Set Collection using Spring dependency injection by constructor? | Spring Tutorial
• How to Inject Array of String using Spring dependency injection by Setter method? | Spring Tutorial
• How to create a concrete List collection (ArrayList and LinkedList) using ListFactoryBean in Spring

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How to Inject Array of String using Spring dependency injection by constructor? | Spring Tutorial

How to Inject Array of String using Spring dependency injection by constructor? | Spring Tutorial

How to Inject Array of String using Spring dependency injection by constructor? | Spring Tutorial