Create a Data Access Object for MySQL Data using JDBI

JDBI is a SQL convenience library for Java that exposes two different style APIs, a fluent style and a SQL object style. The CData JDBC Driver for MySQL integrates connectivity to live MySQL data in Java applications. By pairing these technologies, you gain simple, programmatic access to MySQL data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read and write MySQL data.

Create a DAO for the MySQL Orders Entity

The interface below declares the desired behavior for the SQL object to create a single method for each SQL statement to be implemented.

public interface MyOrdersDAO {
 //insert new data into MySQL
 @SqlUpdate("INSERT INTO Orders (ShipCountry, Freight) values (:shipCountry, :freight)")
 void insert(@Bind("shipCountry") String shipCountry, @Bind("freight") String freight);

 //request specific data from MySQL (String type is used for simplicity)
 @SqlQuery("SELECT Freight FROM Orders WHERE ShipCountry = :shipCountry")
 String findFreightByShipCountry(@Bind("shipCountry") String shipCountry);

 /*
 * close with no args is used to close the connection
 */
 void close();
}

Open a Connection to MySQL

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to MySQL.

The CData Provider supports connecting to on-premises and cloud-hosted versions of MySQL such as Amazon RDS for MySQL, Google Cloud SQL for MySQL, Azure Database for MySQL, or Oracle MySQL HeatWave. The Server and Port properties must be set to a MySQL server. If IntegratedSecurity is set to false, then User and Password must be set to valid user credentials. Optionally, Database can be set to connect to a specific database. If not set, tables from all databases will be returned.

SSH Connectivity for MySQL

You can use SSH (Secure Shell) to authenticate with MySQL, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

SSH Connections to MySQL in Password Auth Mode

To connect to MySQL via SSH in Password Auth mode, set the following connection properties:

• User: MySQL User name
• Password: MySQL Password
• Database: MySQL database name
• Server: MySQL Server name
• Port: MySQL port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Password"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHPassword: SSH Password

SSH Connections to MySQL in Public Key Auth Mode

To connect to MySQL via SSH in Password Auth mode, set the following connection properties:

• User: MySQL User name
• Password: MySQL Password
• Database: MySQL database name
• Server: MySQL Server name
• Port: MySQL port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Public_Key"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHClientCret: the path for the public key certificate file

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the MySQL JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

java -jar cdata.jdbc.mysql.jar

Fill in the connection properties and copy the connection string to the clipboard.

👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)

A connection string for MySQL will typically look like the following:

jdbc:mysql:User=myUser;Password=myPassword;Database=NorthWind;Server=myServer;Port=3306;

Use the configured JDBC URL to obtain an instance of the DAO interface. The particular method shown below will open a handle bound to the instance, so the instance needs to be closed explicitly to release the handle and the bound JDBC connection.

DBI dbi = new DBI("jdbc:mysql:User=myUser;Password=myPassword;Database=NorthWind;Server=myServer;Port=3306;");
MyOrdersDAO dao = dbi.open(MyOrdersDAO.class);

//do stuff with the DAO

dao.close();

Read MySQL Data

With the connection open to MySQL, simply call the previously defined method to retrieve data from the Orders entity in MySQL.

//disply the result of our 'find' method
String freight = dao.findFreightByShipCountry("USA");
System.out.println(freight);

Write MySQL Data

It is also simple to write data to MySQL, using the previously defined method.

//add a new entry to the Orders entity
dao.insert(newShipCountry, newFreight);

Since the JDBI library is able to work with JDBC connections, you can easily produce a SQL Object API for MySQL by integrating with the CData JDBC Driver for MySQL. Download a free trial and work with live MySQL data in custom Java applications today.