Spring dependency checking with Custom @Required Annotation | Spring Tutorial

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Spring dependency checking with Custom @Required Annotation | Spring Tutorial

Spring dependency checking with Custom @Required Annotation | Spring Tutorial

Spring dependency checking with Custom @Required Annotation | 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>

Mandatory.java

package com.ram.custom;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Mandatory
{
}

Address.java

package com.ram.model;

public class Address
{
    private String city;
    private String state;

    public String getCity()
    {
        return city;
    }

    public void setCity(String city)
    {
        this.city = city;
    }

    public String getState()
    {
        return state;
    }

    public void setState(String state)
    {
        this.state = state;
    }

    @Override
    public String toString()
    {
        return "Address [city=" + city + ", state=" + state + "]";
    }

}

Employee.java

package com.ram.model;

import com.ram.custom.Mandatory;

public class Employee
{
    private int id;
    private String name;
    private Address address;

    public int getId()
    {
        return id;
    }

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

    public String getName()
    {
        return name;
    }

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

    public Address getAddress()
    {
        return address;
    }
   
    @Mandatory
    public void setAddress(Address address)
    {
        this.address = address;
    }

    @Override
    public String toString()
    {
        return "Employee [id=" + id + ", name=" + name + ", address=" + address
                + "]";
    }

}

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.3.xsd">

    <bean id="address" class="com.ram.model.Address">
        <property name="city" value="TamilNadu"></property>
        <property name="state" value="Chennai"></property>
    </bean>


    <bean id="employee" class="com.ram.model.Employee">
        <property name="id" value="100"></property>
        <property name="name" value="Peter"></property>
        <!-- <property name="address" ref="address"></property> -->
    </bean>

    <bean
        class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor">
        <property name="requiredAnnotationType" value="com.ram.custom.Mandatory" />
    </bean>

</beans>

App.java

package com.ram.core;

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

import com.ram.model.Employee;

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

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

        Employee employee = context.getBean("employee", Employee.class);
        System.out.println(
                "Got employee object from the ApplicationContext(Spring Container)");

        System.out.println(employee);

    }

}

Output

Aug 06, 2018 9:47:19 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@5b37e0d2: startup date [Mon Aug 06 09:47:19 IST 2018]; root of context hierarchy
Aug 06, 2018 9:47:19 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [applicationContext.xml]
Aug 06, 2018 9:47:20 AM org.springframework.context.support.AbstractApplicationContext refresh
WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employee' defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanInitializationException: Property 'address' is required for bean 'employee'
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employee' defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanInitializationException: Property 'address' is required for bean 'employee'
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:591)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
    at com.ram.core.App.main(App.java:12)
Caused by: org.springframework.beans.factory.BeanInitializationException: Property 'address' is required for bean 'employee'
    at org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor.postProcessPropertyValues(RequiredAnnotationBeanPostProcessor.java:156)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1344)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
    ... 11 more

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

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

Bitbucket Link:
https://bitbucket.org/ramram43210/spring/src/476437cc0ec4e46c307e790b2c10c4099b1c066b/Spring_2018/SpringDemo_custom_required_annotation/?at=master

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