spring 动态创建数据源

public class DynamicDataSource extends AbstractRoutingDataSource {
    private Logger log = Logger.getLogger(this.getClass());
    
    @Autowired
    private CenterDatebaseManager centerDatebaseManager;
    // 默认数据源，也就是主库
    protected DataSource masterDataSource;
    // 保存动态创建的数据源
    private static final Map targetDataSource = new HashMap<>();
    
    @Override
    protected DataSource determineTargetDataSource() {
        // 根据数据库选择方案，拿到要访问的数据库
        String dataSourceName = determineCurrentLookupKey();
        if("dataSource".equals(dataSourceName)) {
            // 访问默认主库
            return masterDataSource;
        }
        
        // 根据数据库名字，从已创建的数据库中获取要访问的数据库
        DataSource dataSource = (DataSource) targetDataSource.get(dataSourceName);
        if(null == dataSource) {
            // 从已创建的数据库中获取要访问的数据库，如果没有则创建一个
            dataSource = this.selectDataSource(dataSourceName);
        }
        return dataSource;
    }
    
    @Override
    protected String determineCurrentLookupKey() {
        // TODO Auto-generated method stub
        String dataSourceName = Dbs.getDbType();
        if (dataSourceName == null || dataSourceName == "dataSource") {
            // 默认的数据源名字
            dataSourceName = "dataSource";
        }
        log.debug("use datasource : " + dataSourceName);
        return dataSourceName;
    }

    /*public void setTargetDataSource(Map targetDataSource) {
        this.targetDataSource = targetDataSource;
        super.setTargetDataSources(this.targetDataSource);
    }*/

    /*public Map getTargetDataSource() {
        return this.targetDataSource;
    }*/

    public void addTargetDataSource(String key, BasicDataSource dataSource) {
        this.targetDataSource.put(key, dataSource);
        //setTargetDataSources(this.targetDataSource);
    }

    
    /**
     * 该方法为同步方法，防止并发创建两个相同的数据库
     * 使用双检锁的方式，防止并发
     * @param dbType
     * @return
     */
    private synchronized DataSource selectDataSource(String dbType) {
        // 再次从数据库中获取，双检锁
        DataSource obj = (DataSource)this.targetDataSource.get(dbType);
        if (null != obj) {
            return obj;
        } 
        // 为空则创建数据库
        BasicDataSource dataSource = this.getDataSource(dbType);
        if (null != dataSource) {
            // 将新创建的数据库保存到map中
            this.setDataSource(dbType, dataSource);
            return dataSource;
        }else {
            throw new SystemException("创建数据源失败！");
        }
    }
    
    /**
     * 查询对应数据库的信息
     * @param dbtype
     * @return
     */
    private BasicDataSource getDataSource(String dbtype) {
        String oriType = Dbs.getDbType();
        // 先切换回主库
        Dbs.setDbType("dataSource");
        // 查询所需信息
        CenterDatebase datebase = centerDatebaseManager.getById(dbtype);
        // 切换回目标库
        Dbs.setDbType(oriType);
        
        String url = "jdbc:sqlserver://" + datebase.getIp() + ":1433"
                + ";DatabaseName=" + datebase.getDatabaseName();
        BasicDataSource dataSource = createDataSource(url,datebase.getUserName(),datebase.getPassword());
        return dataSource;
    }
    
    //创建SQLServer数据源
    private BasicDataSource createDataSource(String url,String userName,String password) {
        return createDataSource("com.microsoft.sqlserver.jdbc.SQLServerDriver", url, userName, password);
    }
    
    //创建数据源
    private BasicDataSource createDataSource(String driverClassName, String url,
            String username, String password) {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setTestWhileIdle(true);

        return dataSource;
    }

    public void setDataSource(String type, BasicDataSource dataSource) {
        this.addTargetDataSource(type, dataSource);
        Dbs.setDbType(type);
    }

/*    @Override
    public void setTargetDataSources(Map targetDataSources) {
        // TODO Auto-generated method stub
        super.setTargetDataSources(targetDataSources);
        // 重点：通知container容器数据源发生了变化
        afterPropertiesSet();
    }*/
    
    
    /**
     * 该方法重写为空，因为AbstractRoutingDataSource类中会通过此方法将，targetDataSources变量中保存的数据源交给resolvedDefaultDataSource变量
     * 在本方案中动态创建的数据源保存在了本类的targetDataSource变量中。如果不重写该方法为空，会因为targetDataSources变量为空报错
     * 如果仍然想要使用AbstractRoutingDataSource类中的变量保存数据源，则需要在每次数据源变更时，调用此方法来为resolvedDefaultDataSource变量更新
     */
    @Override
    public void afterPropertiesSet() {
    }

    public DataSource getMasterDataSource() {
        return masterDataSource;
    }

    public void setMasterDataSource(DataSource masterDataSource) {
        this.masterDataSource = masterDataSource;
    }
    
    
}

public class Dbs {
    private static final ThreadLocal<String> local = new ThreadLocal<String>();
       
    public static String getDbType(){
        return local.get();
    }
   
    public static void setDbType(String dbName){
        local.set(dbName);
    }
   
    public static void clear(){
        local.remove();
    }
}

<!-- 引入jdbc配置文件 -->  
    <context:property-placeholder location="classpath:jdbc.properties" /> 
    
    <!--创建jdbc数据源 -->  
    <bean id="masterDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">  
        <property name="driverClassName" value="${jdbc.driverClassName}" />  
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />  
        <property name="password" value="${jdbc.password}" />  
        <property name="initialSize" value="10" /> 
        <property name="maxActive" value="50" /> 
        <property name="maxIdle" value="15" /> 
        <property name="minIdle" value="5" /> 
        <property name="removeAbandoned" value="true" /> 
        <property name="removeAbandonedTimeout" value="60" /> 
        <property name="maxWait" value="10000" /> 
        <property name="logAbandoned" value="true" /> 
    </bean>


<!--多数据源  -->
    <bean id="multipleDataSource"  class="com.zoneking.basis.dynamicDB.DynamicDataSource">
          <property name="masterDataSource"  ref="masterDataSource"></property>
    </bean>