Spring動態註冊bean實現動態多數據源

#鏈接數據庫地址，該地址可動態添加，「link.」以後，「.jdbc」以前的名稱爲數據庫鏈接池的名稱，
#其他鏈接池屬性若是不寫，將自動繼承Hummer的數據庫鏈接池配置
link.eagle2.business.jdbc.jdbcUrl=jdbc:oracle:thin:@192.168.0.155:1521:orcl
link.eagle2.business.jdbc.user=eagle2
link.eagle2.business.jdbc.password=eagle2_password
link.eagle2.interface.jdbc.jdbcUrl=jdbc:oracle:thin:@192.168.0.155:1521:interface
link.eagle2.interface.jdbc.user=interface
link.eagle2.interface.jdbc.password=interface22
link.eagle2.ods.jdbc.jdbcUrl=jdbc:oracle:thin:@192.168.0.10:1521:sifen
link.eagle2.ods.jdbc.user=honghe
link.eagle2.ods.jdbc.password=honghe_pwd

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.ChildBeanDefinition;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.core.io.support.ResourcePropertySource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DynamicDataSourceC3p0 implements 
ApplicationContextAware,ApplicationListener {

    private ApplicationContext app;
    @Override
    public void setApplicationContext(ApplicationContext app)
            throws BeansException {
        this.app = app;
    }
    public void onApplicationEvent(ApplicationEvent event) {  
        //若是是容器刷新事件  
        if(event instanceof ContextRefreshedEvent ){//若是是容器關閉事件  
            try {
                regDynamicBean();
            } catch (IOException e) {
                e.printStackTrace();
            }
            //System.out.println(event.getClass().getSimpleName()+" 事件已發生！");
        }
    }  

    private void regDynamicBean() throws IOException{
        // 解析屬性文件，獲得數據源Map
        Map<String, DataSourceInfo> mapCustom=
        parsePropertiesFile("hummer.properties");
        // 把數據源bean註冊到容器中
        addSourceBeanToApp(mapCustom);
        
    }
    /**
     * 功能說明：根據DataSource建立bean並註冊到容器中
     * @param acf
     * @param mapCustom
     */
    private void addSourceBeanToApp(Map<String, DataSourceInfo> mapCustom) {
        DefaultListableBeanFactory acf = (DefaultListableBeanFactory) 
        app.getAutowireCapableBeanFactory();
        BeanDefinition beanDefinition;
        Iterator<String> iter = mapCustom.keySet().iterator();
        while(iter.hasNext()){
            String beanKey = iter.next();
            // 獲得Bean定義，並添加到容器中
            beanDefinition = new ChildBeanDefinition("dataSource");
            // 注意：必須先註冊到容器中，再獲得Bean進行修改，不然數據源屬性不能有效修改
            acf.registerBeanDefinition(beanKey, beanDefinition);
            // 再獲得數據源Bean定義，並修改鏈接相關的屬性
            ComboPooledDataSource cpds = (ComboPooledDataSource)app.getBean( beanKey);

            cpds.setJdbcUrl(mapCustom.get(beanKey).connUrl);
            cpds.setUser(mapCustom.get(beanKey).userName);
            cpds.setPassword(mapCustom.get(beanKey).password);
        }
    }
    /**
     * 功能說明：解析屬性文件，獲得數據源Map
     * @return
     * @throws IOException
     */
    private Map<String, DataSourceInfo> parsePropertiesFile(String fileName) 
    throws IOException {
        // 屬性文件
        ResourcePropertySource props =  new ResourcePropertySource(fileName);
        
        Matcher matcher;
        Pattern pattern = Pattern.compile("^link\\.(eagle2\\.\\w+)\\.jdbc\\.
        (jdbcUrl|user|password)$");
        
        Map<String, DataSourceInfo> mapDataSource = 
        new HashMap<String,DataSourceInfo>();
        // 根據配置文件解析數據源
        for(String keyProp : props.getPropertyNames())
        {
            matcher = pattern.matcher(keyProp);
            if(matcher.find()){
                String dsName = matcher.group(1);
                String dsPropName = matcher.group(2);
                DataSourceInfo dsi;
                
                if(mapDataSource.containsKey(dsName)){
                    dsi = mapDataSource.get(dsName);
                }
                else{
                    dsi = new DataSourceInfo();
                }
                // 根據屬性名給數據源屬性賦值
                if("jdbcUrl".equals(dsPropName)){
                    dsi.connUrl = (String)props.getProperty(keyProp);
                }else if("user".equals(dsPropName)){
                    dsi.userName = (String)props.getProperty(keyProp);
                }else if("password".equals(dsPropName)){
                    dsi.password = (String)props.getProperty(keyProp);
                }
                mapDataSource.put(dsName, dsi);
            }
        }
        return mapDataSource;
    }
    
    private class DataSourceInfo{
        public String connUrl;
        public String userName;
        public String password;
        
        public String toString(){
            
            return "(JcbcUrl:"+connUrl+", user:"+userName+", password:"+password+")";
        }
    }
}

acf.registerBeanDefinition不用判斷容器中是否已經有相應名字的bean，spring會在該名稱的bean存在時覆蓋，

不存在時添加。