Spring Dependency Injection via Constructor [IOutputGenerator] | Spring Tutorial

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Spring Dependency Injection via Constructor [IOutputGenerator] | Spring Tutorial

Spring Dependency Injection via Constructor [IOutputGenerator] | Spring Tutorial

pom.xml

<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%20http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.ram.core</groupId>
    <artifactId>SpringDemo</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>SpringDemo</name>
    <url>http://maven.apache.org</url>

    <properties>
        <spring.version>5.0.2.RELEASE</spring.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>

        <!-- Spring 5 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
    </dependencies>
</project>

IOutputGenerator.java

package com.ram.core;

public interface IOutputGenerator
{
    public abstract void generate();
}

JsonOutputGenerator.java

package com.ram.core.impl;

import com.ram.core.IOutputGenerator;

public class JsonOutputGenerator implements IOutputGenerator
{

    public void generate()
    {
        System.out.println("Generate Json file.");
    }

}

CsvOutputGenerator.java

package com.ram.core.impl;

import com.ram.core.IOutputGenerator;

public class CsvOutputGenerator implements IOutputGenerator
{

    public void generate()
    {
        System.out.println("Generate csv file.");
    }

}

OutputHelper.java

package com.ram.core;

public class OutputHelper
{
    private IOutputGenerator outputGenerator;

    public OutputHelper(IOutputGenerator outputGenerator)
    {
        this.outputGenerator = outputGenerator;
    }

    public IOutputGenerator getOutputGenerator()
    {
        return outputGenerator;
    }

}

applicationContext.xml

<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-4.3.xsd">

    <bean id="csvOutputGenerator" class="com.ram.core.impl.CsvOutputGenerator" />
    <bean id="jsonOutputGenerator" class="com.ram.core.impl.JsonOutputGenerator" />

    <bean id="outputHelper" class="com.ram.core.OutputHelper">
        <constructor-arg  ref="jsonOutputGenerator"></constructor-arg>
    </bean>

</beans>

App.java

package com.ram.core;

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

public class App
{
    public static void main(String[] args)
    {
        ApplicationContext context = new ClassPathXmlApplicationContext(
                "applicationContext.xml");

        System.out.println("---------------------------------------");

        OutputHelper outputHelper = (OutputHelper) context.getBean("outputHelper");
        System.out.println(
                "Got outputHelper object from the ApplicationContext(Spring container)");
     
        IOutputGenerator outputGenerator = outputHelper.getOutputGenerator();
     
        System.out.println(outputGenerator.getClass().getName());
     
        outputGenerator.generate();
    }

}

Output

Jun 24, 2018 9:35:03 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@5b37e0d2: startup date [Sun Jun 24 09:35:03 IST 2018]; root of context hierarchy
Jun 24, 2018 9:35:03 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [applicationContext.xml]
---------------------------------------
Got outputHelper object from the ApplicationContext(Spring container)
com.ram.core.impl.JsonOutputGenerator
Generate Json file.

Click the below link to download the code:
https://sites.google.com/site/ramj2eev2/java_basics/SpringDemo_ConsInjection_OutputGenerator.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/javaee/tree/master/Spring_2018/SpringDemo_ConsInjection_OutputGenerator

Bitbucket Link:
https://bitbucket.org/ramram43210/spring/src/2e61326861cb70081e827e56925bac625eae7b3a/Spring_2018/SpringDemo_ConsInjection_OutputGenerator/?at=master

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