In this example, we are using the DatabaseMetaData to retrieve table’s column names. The metadata information can be obtained by calling the connection.getMetaData(). Next, we can then get a ResultSet object by calling metadata.getColumns() method and passing the catalog name, schema pattern, table name pattern, and column name pattern.

From this result set COLUMN_NAME, TYPE_NAME, COLUMN_SIZE and other information can be read.

package org.kodejava.jdbc;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DbMetadataExample {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "kodejava";
    private static final String PASSWORD = "s3cr*t";

    public static void main(String[] args) {
        try (Connection connection =
                     DriverManager.getConnection(URL, USERNAME, PASSWORD)) {

            DatabaseMetaData metadata = connection.getMetaData();
            ResultSet resultSet =
                    metadata.getColumns("kodejava", null, "book", null);

            while (resultSet.next()) {
                String name = resultSet.getString("COLUMN_NAME");
                String type = resultSet.getString("TYPE_NAME");
                int size = resultSet.getInt("COLUMN_SIZE");

                System.out.println("Column name: [" + name + "]; " +
                        "type: [" + type + "]; size: [" + size + "]");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

A bit information of book table described below:

Column name: [id]; type: [BIGINT UNSIGNED]; size: [20]
Column name: [isbn]; type: [VARCHAR]; size: [50]
Column name: [title]; type: [VARCHAR]; size: [100]
Column name: [published_year]; type: [INT]; size: [10]
Column name: [price]; type: [DECIMAL]; size: [10]

Maven Dependencies

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.4.0</version>
</dependency>