BeanFactoryPostProcessor简介:
BeanFactory后处理器，实现BeanFactoryPostProcessor接口，也成为容器后处理器。
容器后处理器在bean创建之前，修改bean的定义属性。
bean的生命周期:
BeanFactoryPostProcessor->代码块->实例化->数据装配->初始化之前->初始化方法->初始化之后->就绪->使用->销毁方法->从容器销毁
实现步骤:
一:定义一个类，实现BeanFactoryPostProcessor
二：将该bean添加到ioc容器中。
三：定义属性编辑器（转换器）实现PropertyEditorJ接口或者实现PropertyEditorSupport;
四：在容器后处理器中注册属性编辑器
先添加jar包
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<!--spring-core-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
</dependency>
<!--spring-bean-->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
</dependency>
<!--spring-context-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</dependency>
<!--spring-expression-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
</dependency>
</dependencies>
第二步创建配置文件spring.xml
<?xml version="1.0" encoding="UTF-8"?>
<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.xsd">
</beans>
第三步书写一个类Address
package com.ioc17.entity;
/**
* package_name:com.ioc17.entity
* Author:徐亚远
* Date:2020/2/16 12:06
* 项目名:springDemo01
* Desription:
**/
public class Address {
private String province;
private String city;
@Override
public String toString() {
return "Address{" +
"province='" + province + '\'' +
", city='" + city + '\'' +
'}';
}
public String getProvince() {
return province;
}
public void setProvince(String province) {
this.province = province;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}
书写RefAddress类
package com.ioc17.entity;
/**
* package_name:com.ioc17.entity
* Author:徐亚远
* Date:2020/2/16 12:07
* 项目名:springDemo01
* Desription:
**/
public class RefAddress {
private Address address;
{
System.out.println("代码块");
}
@Override
public String toString() {
return "RefAddress{" +
"address=" + address +
'}';
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
}
定义一个类，实现BeanFactoryPostProcessor
package com.ioc17.entity;
import com.ioc17.editor.AddressEditor;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
/**
* package_name:com.ioc17.entity
* Author:徐亚远
* Date:2020/2/16 12:21
* 项目名:springDemo01
* Desription:
**/
public class RefAddressBeanPostProcessor implements BeanFactoryPostProcessor {
/**
* Modify the application context's internal bean factory after its standard
* initialization. All bean definitions will have been loaded, but no beans
* will have been instantiated yet. This allows for overriding or adding
* properties even to eager-initializing beans.
*
* @param beanFactory the bean factory used by the application context
* @throws BeansException in case of errors
*/
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
System.out.println("hello");
/**第一个属性是要转换的属性类型，第二个属性是转换器类*/
beanFactory.registerCustomEditor(Address.class,AddressEditor.class);
}
}
将bean添加到ioc容器中配置spring.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<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.xsd">
<bean id="refAddress" class="com.ioc17.entity.RefAddress">
<property name="address" value="[河南-商丘]"/>
</bean>
</beans>
定义属性编辑器（转换器）实现PropertyEditorJ接口或者实现PropertyEditorSupport;
package com.ioc17.editor;
import com.ioc17.entity.Address;
import java.beans.PropertyEditorSupport;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* package_name:com.ioc17.editor
* Author:徐亚远
* Date:2020/2/18 15:18
* 项目名:springDemo01
* Desription:转换器
**/
public class AddressEditor extends PropertyEditorSupport {
/**
* 获取字符串将Address转换成字符串
*/
@Override
public String getAsText() {
Address address = (Address) getValue();
return "["+address.getProvince()+"-"+address.getCity()+"]";
}
/**
* @param text 将字符串转换成Address
*/
@Override
public void setAsText(String text) throws IllegalArgumentException {
Pattern pattern = Pattern.compile("\\[(.*)-(.*)\\]");
Matcher matcher = pattern.matcher(text);
if (matcher.matches()) {
String city = matcher.group(1);
String province = matcher.group(2);
Address address = new Address();
address.setCity(city);
address.setProvince(province);
setValue(address);
}
}
}
在容器后处理器中注册属性编辑器
<?xml version="1.0" encoding="UTF-8"?>
<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.xsd">
<bean id="refAddress" class="com.ioc17.entity.RefAddress">
<property name="address" value="[河南-商丘]"/>
</bean>
<!--在容器后处理器中注册属性编辑器-->
<bean id="postProcessor" class="com.ioc17.entity.RefAddressBeanPostProcessor"></bean>
</beans>
书写测试类
package com.ioc17.controller;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* package_name:com.ioc17.controller
* Author:徐亚远
* Date:2020/2/16 12:08
* 项目名:springDemo01
* Desription:
**/
public class TestRef {
public static void main(String [] args){
ApplicationContext ac = new ClassPathXmlApplicationContext("ioc17/spring.xml");
System.out.println(ac.getBean("refAddress"));
}
}
测试结果：
