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To retrieve table names along with their join columns using JSQLProcessor, you can use the following steps:

1. Create a JSQLProcessor instance by providing a Connection object to the constructor.

2. Use the "select" method to select the table names and join columns from the database. You can use the "AS" keyword to assign aliases to the table names and join columns.

3. Use the "from" method to specify the tables you want to select from.

4. Use the "joinOn" method to specify the join conditions.

5. Use the "executeQuery" method to execute the query and retrieve the results.

6. Iterate over the ResultSet object to retrieve the results and print them to the console or do other processing as required.

Here's an example code snippet that demonstrates how to retrieve table names along with their join columns using JSQLProcessor:

import java.sql.*;
import com.jsql.*;

public class JoinQuery {
   public static void main(String[] args) {
      try {
         // Create a JSQLProcessor instance by providing a Connection object
         JSQLProcessor jsql = new JSQLProcessor(DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "password"));

         // Select the table names and join columns using aliases
         String query = "SELECT t1.*, t2.col2 AS t2_col2 FROM table1 t1 JOIN table2 t2 ON t1.col1 = t2.col1";

         // Specify the tables to select from and join conditions
         jsql.select(query).from("table1", "table2").joinOn("table1.col1", "=", "table2.col1");

         // Execute the query and retrieve the results
         ResultSet resultSet = jsql.executeQuery();

         // Iterate over the results and print them to the console
         while (resultSet.next()) {
            System.out.println(resultSet.getString("t1_col1") + ", " + resultSet.getString("t1_col2") + ", " + resultSet.getString("t2_col2"));
         }

         // Close the ResultSet and JSQLProcessor
         resultSet.close();
         jsql.close();
      } catch (SQLException e) {
         e.printStackTrace();
      }
   }
}

In this example, the query selects all columns from table1 and column "col2" from table2, with an alias "t2_col2". The query then specifies the tables to select from and join condition. Finally, it retrieves the ResultSet from jsql and prints the results retrieved from the ResultSet.