mysql动态连接数据库

1.配置xml文件

applicationContext.xml
<bean id="defaultDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
  <property name="driverClassName" value="${default.driver}" />
  <property name="url" value="${default.url}" />
  <property name="username" value="${default.username}" />
  <property name="password" value="${default.password}" />
 </bean>
 <bean id="dataSource" class="com.ceict.ems.common.db.DynamicDataSource">
  <property name="targetDataSources">
   <map>
    <entry key="default" value-ref="defaultDataSource" />
   </map>
  </property>
 </bean>

2.编写动态连接的接口:

public class DynamicDataSource extends AbstractRoutingDataSource {
    private Map<Object, Object> _targetDataSources;
    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceContextHolder.getDataSource();
    }
    public void setTargetDataSources(Map<Object, Object> targetDataSources) {
        this._targetDataSources = targetDataSources;
        super.setTargetDataSources(targetDataSources);
        afterPropertiesSet();
    }
    public String getDbtype(String key) {
        String driver = ((BasicDataSource) _targetDataSources.get(key))
                .getDriverClassName();
        if ("oracle.jdbc.driver.OracleDriver".equals(driver)) {
            return "oracle";
        } else if ("com.mysql.jdbc.Driver".equals(driver)) {
            return "mysql";
        }
        return null;
    }
    public void addTargetDataSource(String key, DataSource dataSource) {
        _targetDataSources.put(key, dataSource);
        this.setTargetDataSources(_targetDataSources);
    }
    public static DataSource 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);
        if ("oracle.jdbc.driver.OracleDriver".equals(driverClassName)) {
            dataSource.setValidationQuery("SELECT 1 FROM DUAL");
        } else if ("com.mysql.jdbc.Driver".equals(driverClassName)) {
            dataSource.setValidationQuery("SELECT NOW()");
        }
        return dataSource;
    }
}

3.测试：

DynamicDataSource dynamicDataSource = ApplicationUtil                .getBean(DynamicDataSource.class);        BasicDataSource dataSource = DynamicDataSource.createDataSource(driverClassName,url,userName,password)                dynamicDataSource.addTargetDataSource("dbkey", dataSource );                      DataSourceContextHolder.setDataSource("dbkey");        // 通过以上语句可以将数据库连接配置修改为当前设置的         //执行自己的DAO方法          DataSourceContextHolder.clearDataSource();//恢复数据库的配置为applicationContext.xml默认的配置