Setter Dependency Injection with Array of String

In some scenarios, we may need to inject an array of strings to an object.

Consider the example where Person has hobbies

In this case, we can use Array of String which stores the hobbies

Let us see the same in spring through Setter Dependency Injection

Create a class called Person

It contains 3 attributes id,name and hobbies where hobbies is an array of String.

It contains 3 setter methods one for each attribute

It also contains showHobbies() method to display the hobbies injected to the person object.

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package com.kb.di;
 
public class Person {
    private int id;
    private String name;
    private String[] hobbies;
    
    public void showHobbies() {
        for (int i = 0; i < hobbies.length; i++) {
            System.out.println(hobbies[i]);
        }
 
    }
 
    public void setId(int id) {
        this.id = id;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public void setHobbies(String[] hobbies) {
        this.hobbies = hobbies;
    }
}
package com.kb.di;

public class Person {
	private int id;
	private String name;
	private String[] hobbies;
	
	public void showHobbies() {
		for (int i = 0; i < hobbies.length; i++) {
			System.out.println(hobbies[i]);
		}

	}

	public void setId(int id) {
		this.id = id;
	}

	public void setName(String name) {
		this.name = name;
	}

	public void setHobbies(String[] hobbies) {
		this.hobbies = hobbies;
	}
}

Create a spring bean definition file

In this file, we used < property > tag with < array > to define the hobbies

< array > tag is used to inject the hobbies defined as array of strings in the Person class.

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
 
 
    <bean id="person" class="com.kb.di.Person">
        <property name="id" value="1"></property>
        <property name="name" value="Raj"></property>
        <property name="hobbies">
            <array>
                <value>Playing cricket</value>
                <value>Coding</value>
                <value>Reading books</value>
            </array>
 
        </property>
    </bean>
</beans>
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">


	<bean id="person" class="com.kb.di.Person">
		<property name="id" value="1"></property>
		<property name="name" value="Raj"></property>
		<property name="hobbies">
			<array>
				<value>Playing cricket</value>
				<value>Coding</value>
				<value>Reading books</value>
			</array>

		</property>
	</bean>
</beans>

Create a pom.xml file

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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
 
  <groupId>Spring</groupId>
  <artifactId>SpringCore</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>
 
  <name>SpringCore</name>
  <url>http://maven.apache.org</url>
 
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
 
  <dependencies>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>4.2.4.RELEASE</version>
</dependency>
  
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>Spring</groupId>
  <artifactId>SpringCore</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>SpringCore</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
  <dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-core</artifactId>
	<version>4.2.4.RELEASE</version>
</dependency>
  <dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-context</artifactId>
	<version>4.2.4.RELEASE</version>
</dependency>
  
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

Create a SetterDI class

This class loads the spring beans using application context and calls the person class method to display the hobbies.

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package com.kb.di;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class SetterDI  {
    
    public static void main(String[] args) {
        ApplicationContext applicationContext=new ClassPathXmlApplicationContext("beans.xml");  
        Person person = (Person)applicationContext.getBean("person");
        person.showHobbies();
    
    }
 
}
package com.kb.di;

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

public class SetterDI  {
	
	public static void main(String[] args) {
        ApplicationContext applicationContext=new ClassPathXmlApplicationContext("beans.xml");  
        Person person = (Person)applicationContext.getBean("person");
        person.showHobbies();
    
	}

}

Run the SetterDI class and see the output as below

Download this project SetterDIWithArrayOfString.zip

About the Author

Karibasappa G C (KB)
Founder of javainsimpleway.com
I love Java and open source technologies and very much passionate about software development.
I like to share my knowledge with others especially on technology 🙂
I have given all the examples as simple as possible to understand for the beginners.
All the code posted on my blog is developed,compiled and tested in my development environment.
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