mysql动态连接数据库

矫情吗；* 2022-08-13 11:54 205阅读 0赞

**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