07点睛Spring 4.1-BeanPostProcessor

7.1 BeanPostProcessor

springは、BeanPostProcessorインタフェースを介して、すべてのbeanまたは指定されたいくつかのbeanの初期化前後のbeanのチェックまたは変更をサポートすることができる.

postProcessBeforeInitializationとpostProcessAfterInitializationを使用してbeanを操作します.

postProcessBeforeInitializationおよびpostProcessAfterInitializationの戻り値はbeanです.

7.2例
7.2.1全ての処理bean
7.2.1.1試験用のbeanを2つ新規作成する

package com.wisely.beanpostprocessor;

import org.springframework.stereotype.Service;

@Service
public class DemoNormal1Service {

}

package com.wisely.beanpostprocessor;

import org.springframework.stereotype.Service;

@Service
public class DemoNormal2Service {

}

7.2.1.2すべてのbeanを処理するBeanPostProcessorを作成する

package com.wisely.beanpostprocessor;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;

@Component
public class DemoAllBeanPostProcessor implements BeanPostProcessor{

    public Object postProcessBeforeInitialization(Object bean, String beanName)
            throws BeansException {
        System.out.println("  DemoAllBeanPostProcessor "
        +postProcessBeforeInitialization     bean: " + beanName
        +" bean    :"+bean.getClass());
        return bean;
    }

    public Object postProcessAfterInitialization(Object bean, String beanName)
            throws BeansException {
        System.out.println("  DemoAllBeanPostProcessor "+
        postProcessAfterInitialization     bean: " + beanName
        +" bean    :"+bean.getClass());
        return bean;
    }

}

7.2.1.3テスト

package com.wisely.beanpostprocessor;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Main {

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context =  
                 new AnnotationConfigApplicationContext("com.wisely.beanpostprocessor");
        context.close();

    }

}

出力結果:

  DemoAllBeanPostProcessor postProcessBeforeInitialization     bean:
demoNormal1Service bean    :class com.wisely.beanpostprocessor.DemoNormal1Service
  DemoAllBeanPostProcessor postProcessAfterInitialization     bean:
demoNormal1Service bean    :class com.wisely.beanpostprocessor.DemoNormal1Service
  DemoAllBeanPostProcessor postProcessBeforeInitialization     bean:
demoNormal2Service bean    :class com.wisely.beanpostprocessor.DemoNormal2Service
  DemoAllBeanPostProcessor postProcessAfterInitialization     bean:
demoNormal2Service bean    :class com.wisely.beanpostprocessor.DemoNormal2Service

7.2.2指定されたbeanの処理
7.2.2.2新規指定処理のbean
OSとnum属性に値が割り当てられており、BeanPostProcessorの実装クラスでクラスの属性が変更されます.

package com.wisely.beanpostprocessor;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class DemoSelectedService {
    @Value("#{systemProperties['os.name']}")
    private String os;
    @Value("123")
    private Long num;

    public String getOs() {
        return os;
    }

    public void setOs(String os) {
        this.os = os;
    }

    public Long getNum() {
        return num;
    }

    public void setNum(Long num) {
        this.num = num;
    }


}

7.2.2.3指定beanのBeanPostProcessorの作成

packagecom.wisely.beanpostprocessor;

importorg.springframework.beans.BeansException;
importorg.springframework.beans.factory.config.BeanPostProcessor;
importorg.springframework.stereotype.Component;
@Component

public class DemoSelectedBeanPostProcessor implements BeanPostProcessor {

    public Object postProcessBeforeInitialization(Objectbean, StringbeanName)
            throwsBeansException {
        if(bean instanceof DemoSelectedService){
            ((DemoSelectedService) bean).setOs("Linux");
            System.out.println(" DemoSelectedBeanPostProcessor "+"postProcessBeforeInitialization  os windows    Linux" );
        }
        return bean;
    }

    public Object postProcessAfterInitialization(Objectbean, StringbeanName)
            throwsBeansException {
        if(bean instanceof DemoSelectedService){
            ((DemoSelectedService) bean).setNum(456);
            System.out.println(" DemoSelectedBeanPostProcessor "+"postProcessBeforeInitialization  num 123    456" );
        }
        return bean;
    }

}

7.2.2.4テスト

package com.wisely.beanpostprocessor;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Main {

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context =
                 new  AnnotationConfigApplicationContext("com.wisely.beanpostprocessor");
        DemoSelectedService dss = context.getBean(DemoSelectedService.class);
        System.out.println("os       "+dss.getOs());
        System.out.println("num       "+dss.getNum());
        context.close();

    }

}

出力結果

 DemoSelectedBeanPostProcessor postProcessBeforeInitialization  os windows    Linux
 DemoSelectedBeanPostProcessor postProcessBeforeInitialization  num 123    456
os       Linux
num       123