利用calcite实现多数据源分布式join

public static void main(String[] args) throws Exception{

    // 测试 demo，未设置 ideaMaxTime（超过空闲时间释放jdbc连接）

    while (true){

        long start= System.currentTimeMillis();

        Class.forName("org.apache.calcite.jdbc.Driver");

        Properties info= new Properties();

        info.setProperty("lex", "JAVA");

        Connection connection= DriverManager.getConnection("jdbc:calcite:", info);

        CalciteConnection calciteConnection= connection.unwrap(CalciteConnection.class);

        SchemaPlus rootSchema= calciteConnection.getRootSchema();

        //db1

        Class.forName("com.mysql.cj.jdbc.Driver");

        BasicDataSource ds1= new BasicDataSource();

        ds1.setUrl("jdbc:mysql://localhost:3310/fire_control_acceptance?useUnicode=true&serverTimezone=UTC&allowMultiQueries=true&characterEncoding=utf-8&useSSL=false&nullNamePatternMatchesAll=true");

        ds1.setUsername("root");

        ds1.setPassword("winsion123");

        Schema schema1= JdbcSchema.create(rootSchema, "fire_control_acceptance",

                ds1, null, "fire_control_acceptance");

        rootSchema.add("fire_control_acceptance", schema1);

        //db2

        Class.forName("com.mysql.cj.jdbc.Driver");

        BasicDataSource ds2= new BasicDataSource();

        ds2.setUrl("jdbc:mysql://localhost:3310/fire_maintenance?useUnicode=true&serverTimezone=UTC&allowMultiQueries=true&characterEncoding=utf-8&useSSL=false&nullNamePatternMatchesAll=true");

        ds2.setUsername("root");

        ds2.setPassword("winsion123");

        Schema schema2= JdbcSchema.create(rootSchema, "fire_maintenance",

                ds2, null, "fire_maintenance");

        rootSchema.add("fire_maintenance", schema2);

        Statement statement= calciteConnection.createStatement();

        ResultSet resultSet= statement.executeQuery(

                "select f.factory_id, fc.factory_name, f.name " +

                        "from fire_maintenance.cf_fac f " +

                        "join fire_control_acceptance.f_factory fc " +

                        "on f.factory_id = fc.factory_id");

        // resultSet 转list

        List list= new ArrayList();

        int columnCount= resultSet.getMetaData().getColumnCount();

        Map rowData;

        while (resultSet.next()) {

            rowData= new HashMap(columnCount);

            for (int i= 1; i<= columnCount; i++) {

                rowData.put(resultSet.getMetaData().getColumnName(i), resultSet.getObject(i));

}

            list.add(rowData);

}

        System.out.println(list);

        resultSet.close();

        statement.close();

        connection.close();

        long end= System.currentTimeMillis();

        System.out.println(end- start);

    }