how to use mysql table's regular expression match spark real time date by java

To match real-time date in a MySQL table using regular expressions in Java in Apache Spark, you can follow these steps:

1. Create a SparkSession object to connect to the Spark cluster.

2. Load the MySQL table into a Spark DataFrame using the JDBC connector. You can specify the regular expression pattern for the date column in the SQL query.

3. Use the filter() method of the DataFrame to apply the regular expression pattern on the date column. This will return a new DataFrame containing only the rows that match the pattern.

4. Finally, use the show() method of the filtered DataFrame to display the matching rows.

Here's an example code snippet that demonstrates this approach:

import org.apache.spark.sql.SparkSession

public class MyApp {
  public static void main(String[] args) {
    // Create a SparkSession object
    SparkSession spark = SparkSession.builder()
      .appName("MyApp")
      .master("local[*]")
      .getOrCreate();

    // Load the MySQL table into a DataFrame
    String url = "jdbc:mysql://localhost:3306/mydb";
    String query = "SELECT * FROM mytable WHERE date_column REGEXP '^[0-9]{4}-[0-9]{2}-[0-9]{2}$'";
    Dataset<Row> df = spark.read().format("jdbc")
      .option("url", url)
      .option("query", query)
      .load();

    // Filter the DataFrame using regular expression match
    Dataset<Row> filteredDf = df.filter("date_column REGEXP '^[0-9]{4}-[0-9]{2}-[0-9]{2}$'");

    // Display the filtered DataFrame
    filteredDf.show();
  }
}

In this example, we're assuming that the date column in the MySQL table is named "date_column". The regular expression pattern used in the query and filter method matches the standard YYYY-MM-DD format for dates. You can modify the regular expression pattern to match your specific date format.