列出Flink SQL作业中的所有源和汇

import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.TableEnvironment;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;

public class FlinkSQLExample {
    public static void main(String[] args) throws Exception {
        // 创建执行环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        TableEnvironment tableEnv = TableEnvironment.create(env);

        // 注册 Kafka 源
        tableEnv.executeSql("CREATE TABLE kafka_source (" +
                " id INT, " +
                " name STRING, " +
                " event_time TIMESTAMP(3), " +
                " WATERMARK FOR event_time AS event_time - INTERVAL '5' SECOND" +
                ") WITH (" +
                " 'connector' = 'kafka', " +
                " 'topic' = 'test_topic', " +
                " 'properties.bootstrap.servers' = 'localhost:9092', " +
                " 'format' = 'json'" +
                ")");

        // 注册 HDFS 汇
        tableEnv.executeSql("CREATE TABLE hdfs_sink (" +
                " id INT, " +
                " name STRING, " +
                " event_time TIMESTAMP(3)" +
                ") WITH (" +
                " 'connector' = 'filesystem', " +
                " 'path' = 'hdfs://localhost:9000/output/', " +
                " 'format' = 'csv'" +
                ")");

        // 执行 SQL 查询并将结果写入汇
        tableEnv.executeSql("INSERT INTO hdfs_sink " +
                "SELECT id, name, event_time FROM kafka_source");
    }
}