spring学习

Posted 2021-01-16 寒潭渡鹤影

 

bean配置

启用注解

<context:annotation-config/>

使用spring的特殊bean

对bean

BeanPostProcessor

spring本身提供的特殊bean

1.实现了BeanPostProcessor的后置处理器

2.PropertyPlaceholderConfigurer.

分散配置（有两种方式引入文件）

使用spring的特殊bean，完成分散配置。

beans.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" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    
    xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
      http://www.springframework.org/schema/context
      http://www.springframework.org/schema/context/spring-context-3.2.xsd
      http://www.springframework.org/schema/aop
      http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
      http://www.springframework.org/schema/tx
      http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
      http://www.springframework.org/schema/mvc
      http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
      ">
<!-- 引入我们的db. -->
<context:property-placeholder location="classpath:com/hsp/dispatch/db.properties,classpath:com/hsp/dispatch/db2.properties"/>

<bean id="dbutil" class="com.hsp.dispatch.DBUtil">
<property name="name" value="${name}"/>
<property name="drivername" value="${drivername}"/>
<property name="url" value="${url}"/>
<property name="pwd" value="${pwd}"/>
</bean>


<bean id="dbutil2" class="com.hsp.dispatch.DBUtil">
<property name="name" value="${name}"/>
<property name="drivername" value="${drivername}"/>
<property name="url" value="${url}"/>
<property name="pwd" value="${pwd}"/>

</bean>
</beans>

说明：当通过context:property-placeholder引入属性文件的时候，有多个需要使用,号间隔。

package com.hsp.dispatch;

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

public class App1 {
    public static void main(String[] args) {
        
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/hsp/dispatch/beans.xml");
        
        DBUtil dbUtil = (DBUtil)ac.getBean("dbutil2");
        System.out.println(dbUtil.getDrivername());
        System.out.println(dbUtil.getName());
        System.out.println(dbUtil.getUrl());
        System.out.println(dbUtil.getPwd());
        
    }
    
}

db2.properties

name=root2
drivername=oracle:jdbc:driverDriver2
url=jdbc:oracle:thin:@127.0.0.1:1521:hsp2
pwd=tiger2

使用占位符变量代替bean装配文件中的硬编码配置。占位符采用${variable}形式。