operations to save and read clobs, blobs in mysql

SavesAndReadBlobsAndClobs.java

package com.pluralsight.jdbc.course.m6c1;

import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.sql.*;

public class SavesAndReadBlobsAndClobs
{
    private final String URL
        = "jdbc:mysql://localhost:3306/classicmodels?user=root&password=my-secret-pw";

    /**
     *  Stores a text file in a row in a specific column in the database
     *
     * @param columnName The name of the column to which we will assign the data
     * @param inStream One {@link InputStreamReader} with the data to
     * @return True if ok
     * @throws SQLException Any exception occurred
     */
    public boolean storeClob(String columnName, InputStreamReader inStream) throws SQLException
    {
        String query = "UPDATE productlines SET htmlDescription=? WHERE productLine=?";

        try(Connection connection = DriverManager.getConnection(URL);
            PreparedStatement preparedStatement = connection.prepareStatement(query))
        {
            preparedStatement.setString(2, columnName);
            preparedStatement.setCharacterStream(1, inStream);

            preparedStatement.executeUpdate();
            return true;
        }
    }

    public Reader readClob(String productLine) throws SQLException
    {
        String query = "SELECT htmlDescription FROM productlines WHERE productLine=?";

        try(Connection connection = DriverManager.getConnection(URL);
        PreparedStatement preparedStatement = connection.prepareStatement(query))
        {
            preparedStatement.setString(1, productLine);

            try(ResultSet resultSet = preparedStatement.executeQuery())
            {
                if (resultSet.next())
                {
                    return resultSet.getCharacterStream(1);
                } else
                {
                    return null;
                }
            }
        }
    }

    /**
     * Store a file in a specified row in a table in the database
     *
     * @param columnName The name of the column to which the data will be assigned
     * @param file A {@link FileInputStream} with the data
     * @return True if ok
     * @throws SQLException Any occurred exception
     */
    public boolean storeBlob(String columnName, FileInputStream file) throws SQLException
    {
        String query = "UPDATE productlines SET image=? WHERE productLine=?";

        try(Connection connection = DriverManager.getConnection(URL);
        PreparedStatement preparedStatement = connection.prepareStatement(query))
        {
            preparedStatement.setBinaryStream(1, file);
            preparedStatement.setString(2, columnName);

            int result = preparedStatement.executeUpdate();
            return result > 0;
        }
    }

    public InputStream readBlob(String columnName) throws SQLException
    {
        String query = "SELECT image FROM productlines WHERE productLine=?";

        try(Connection connection = DriverManager.getConnection(URL);
        PreparedStatement statement = connection.prepareStatement(query))
        {
            statement.setString(1, columnName);

            try(ResultSet resultSet = statement.executeQuery();)
            {
                if (resultSet.next())
                {
                    return resultSet.getBinaryStream(1);
                }
            }
        }

        return null;
    }
}