Lazy Init Demo : IoC Init Beans « Spring « Java

1. Java
2. Spring
3. IoC Init Beans

Lazy Init Demo

/*
Pro Spring
By Rob Harrop
Jan Machacek
ISBN: 1-59059-461-4
Publisher: Apress
*/


///////////////////////////////////////////////////////////////////////////////////////
//File: lazy.xml
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="destructiveBean" class="DestructiveBeanWithInterface">
        <property name="filePath">
            <value>c:/test.txt</value>
        </property>
    </bean>
    <bean id="shutdownHook" class="ShutdownHookBean" lazy-init="false"/>
</beans>



///////////////////////////////////////////////////////////////////////////////////////
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;

public class DestructiveBeanWithInterface implements InitializingBean,
        DisposableBean {

    private InputStream is = null;

    public String filePath = null;

    public void afterPropertiesSet() throws Exception {

        System.out.println("Initializing Bean");

        if (filePath == null) {
            throw new IllegalArgumentException(
                    "You must specify the filePath property of " + DestructiveBean.class);
        }

        is = new FileInputStream(filePath);
    }

    public void destroy() {

        System.out.println("Destroying Bean");

        if (is != null) {
            try {
                is.close();
                is = null;
            } catch (IOException ex) {
                System.err.println("WARN: An IOException occured"
                        + " trying to close the InputStream");
            }
        }
    }

    public void setFilePath(String filePath) {
        this.filePath = filePath;
    }
}


///////////////////////////////////////////////////////////////////////////////////////

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

public class ShutdownHookBean implements BeanFactoryAware,
        Runnable {

    private ConfigurableListableBeanFactory factory;

    public void setBeanFactory(BeanFactory factory) throws BeansException {

        if (factory instanceof ConfigurableListableBeanFactory) {
            this.factory = (ConfigurableListableBeanFactory) factory;
            Runtime.getRuntime().addShutdownHook(new Thread(this));
        }
    }

    public void run() {
        if (factory != null) {
            System.out.println("Destroying Singletons");
            factory.destroySingletons();
            System.out.println("Singletons Destroyed");
        }
    }

}

///////////////////////////////////////////////////////////////////////////////////////

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;

public class DestructiveBean implements InitializingBean {

    private InputStream is = null;

    public String filePath = null;

    public void afterPropertiesSet() throws Exception {

        System.out.println("Initializing Bean");

        if (filePath == null) {
            throw new IllegalArgumentException(
                    "You must specify the filePath property of " + DestructiveBean.class);
        }

        is = new FileInputStream(filePath);
    }

    public void destroy() {

        System.out.println("Destroying Bean");

        if (is != null) {
            try {
                is.close();
                is = null;
            } catch (IOException ex) {
                System.err.println("WARN: An IOException occured"
                        + " trying to close the InputStream");
            }
        }
    }

    public void setFilePath(String filePath) {
        this.filePath = filePath;
    }
}

///////////////////////////////////////////////////////////////////////////////////////
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;

public class LazyInitDemo {

    public static void main(String[] args) {
        ApplicationContext ctx = new FileSystemXmlApplicationContext(
                "build/lazy.xml");

        DestructiveBeanWithInterface bean = (DestructiveBeanWithInterface) ctx
                .getBean("destructiveBean");
    }
}

           
       

LazyInitDemo.zip( 1,200 k)

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