spring jdbc

database.properties

subject.driverClassName=oracle.jdbc.driver.OracleDriver
subject.url=jdbc:oracle:thin:@127.0.0.1:instancename
subject.username=username
subject.password=password

context.xml

<bean id="subjectDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">  
    <property name="url" value="${subject.url}" />
    <property name="username" value="${subject.username}" />
    <property name="password" value="${subject.password}" />
    <property name="driverClassName" value="${subject.driverClassName}" />
</bean>

<!-- jdbcTemplate -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="subjectDataSource" />
</bean>

Controller.java

@Controller
public class GeneralRequestController { 
    
    @Autowired
    private JdbcTemplate jdbc;
    
    /**
     * 通用响应请求的方法
     * @return
     */
    @RequestMapping("generalRequest")
    @ResponseBody
    public List<Map<String, String>> generalRequest(HttpServletRequest request) {
        String tableName = request.getParameter("tableName");
        String sql = "select * from " + tableName;

        List<Map<String, String>> resultList = jdbc.query(sql, new RowMapper<Map<String,String>>() {
            public Map<String,String> mapRow(ResultSet rs, int rowNum) throws SQLException {
                Map<String,String> resultMap = new HashMap<String,String>();    
                ResultSetMetaData meta = rs.getMetaData();
                int count = meta.getColumnCount();
                String columnName = "";
                String value = "";
                for(int i=0;i<count;i++) {
                    columnName = meta.getColumnName(i+1);
                    value = rs.getString(columnName);
                    resultMap.put(columnName, value);
                }       
                return resultMap;
            }
        });
        return resultList;
    }
}

context.xml

<bean id="multipleDataSource" class="MultipleDataSource">
    <property name="defaultTargetDataSource" ref="subjectDataSource"></property>
    <property name="targetDataSources">
        <map>
            <entry key="default" value-ref="dataSource" />
            <entry key="subject" value-ref="subjectDataSource" />
        </map>
    </property>
</bean>
    
<!-- JdbcTemplate -->
<bean id="subject" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="multipleDataSource" />
</bean>

MutipleDataSourcce.java

public class MultipleDataSource extends AbstractRoutingDataSource {
    
    /**
     * 默认数据源
     */
    public static final String DEFAULT = "default";
    /**
     * 主题库
     */
    public static final String SUBJECT = "subject";

    private static final ThreadLocal<String> dataSourceKey = new ThreadLocal<String>();

    public static void setDataSourceKey(String dataSource) {
        dataSourceKey.set(dataSource);
    }

    @Override
    protected Object determineCurrentLookupKey() {
        return dataSourceKey.get();
    }

    public static void clear(){
        dataSourceKey.remove();
    }
}

切换数据源

MultipleDataSource.setDataSourceKey(MultipleDataSource.DEFAULT);