Druid Database Connection Pool Access

Introduction

In this project, you will learn how to set up a Druid database connection pool and use it to retrieve data from a MySQL database. Druid is a popular open-source database connection pool that supports various database connections, including MySQL, PostgreSQL, Oracle, and more.

👀 Preview

🎯 Tasks

In this project, you will learn:

• How to set up the Druid database connection pool
• How to implement the getConn() method to return a database connection from the Druid connection pool
• How to retrieve data from the MySQL database using the Druid connection pool

🏆 Achievements

After completing this project, you will be able to:

• Configure and use the Druid database connection pool
• Interact with a MySQL database using a connection pool
• Apply best practices for managing database connections in a Java web application

Set Up the Druid Database Connection Pool

In this step, you will learn how to set up the Druid database connection pool to connect to a MySQL database.

1. Open the DBUtil.java file located in the org.labex.util package.

2. In the DBUtil class, you need to add the following code:

private static DataSource dataSource;

{
    try {
        // Load the Druid configuration from the properties file
        InputStream inputStream = DBUtil.class.getClassLoader().getResourceAsStream("druid.properties");
        Properties properties = new Properties();
        properties.load(inputStream);

        // Create a DruidDataSource based on the configuration
        dataSource = DruidDataSourceFactory.createDataSource(properties);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

This code is responsible for loading the Druid configuration from the druid.properties file and creating a DruidDataSource object based on the configuration.

3. Implement the getConn() method in the DBUtil class to return a database connection from the Druid connection pool:

public Connection getConn() {
    // Get a connection from the DruidDataSource
    Connection conn = null;
    try {
        conn = dataSource.getConnection();
    } catch (SQLException e) {
        e.printStackTrace();
    }

    return conn;
}

This method will return a database connection from the Druid connection pool.

Start the Web Application

In this step, you will learn how to launch the web application and view user information on your browser.

1. In your terminal, navigate to the project directory using the following command:

cd ~/project/DruidProject

2. Run the following command to start the web application:

mvn clean tomcat7:run

3. Open a web browser and go to http://localhost:8080. You will see an input field and a button, in the input field you can enter either Anya or Ethan and click the search button to retrieve data from the database.

The expected result should look like the figure below:

Summary

Congratulations! You have completed this project. You can practice more labs in LabEx to improve your skills.