Common database connection pool problems and solutions in Java development

Common database connection pool problems and solutions in Java development

Introduction:
In Java development, using database connection pools is a common technology Means to improve the efficiency and performance of database connections. However, we often encounter some problems when using database connection pools. This article will introduce some common database connection pool problems and provide corresponding solutions and code examples.

Problem 1: Database connection leakage
Database connection leakage means that the application does not correctly release the connection resources after using the database connection, causing the connection to be occupied for a long time and cannot be reused, thus consuming too much Database connection resources eventually lead to system performance degradation or even crash. The following is a sample code for a solution:

public class ConnectionUtil {
    // 定义一个静态变量用于保存连接池对象
    private static DataSource dataSource;

    // 获取数据库连接
    public static Connection getConnection() throws SQLException {
        // 判断连接池是否已经初始化
        if (dataSource == null) {
            // 初始化连接池
            dataSource = createDataSource();
        }
        // 从连接池中获取连接
        return dataSource.getConnection();
    }

    // 释放数据库连接
    public static void releaseConnection(Connection connection) throws SQLException {
        // 判断连接是否为空
        if (connection != null) {
            // 关闭连接
            connection.close();
        }
    }

    // 创建连接池
    private static DataSource createDataSource() {
        // 创建连接池对象
        BasicDataSource dataSource = new BasicDataSource();
        // 设置连接参数
        dataSource.setUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUsername("root");
        dataSource.setPassword("password");
        // 设置连接池参数
        dataSource.setInitialSize(10);
        dataSource.setMaxTotal(100);
        dataSource.setMaxWaitMillis(10000);
        return dataSource;
    }
}

Problem 2: Connection pool exhaustion
Connection pool exhaustion means that under high concurrency conditions, all connections in the connection pool have been occupied and cannot Serve more connection requests. The following is a sample code for a solution:

public class ConnectionUtil {
    // 定义一个静态变量用于保存连接池对象
    private static DataSource dataSource;

    // 获取数据库连接
    public static Connection getConnection() throws SQLException {
        // 判断连接池是否已经初始化
        if (dataSource == null) {
            // 初始化连接池
            dataSource = createDataSource();
        }
        // 从连接池中获取连接
        Connection connection = dataSource.getConnection();
        // 判断连接是否有效
        if (!connection.isValid(3000)) {
            // 关闭无效连接
            connection.close();
            // 重新获取连接
            connection = dataSource.getConnection();
        }
        return connection;
    }

    // 释放数据库连接
    public static void releaseConnection(Connection connection) throws SQLException {
        // 判断连接是否为空
        if (connection != null) {
            // 关闭连接
            connection.close();
        }
    }

    // 创建连接池
    private static DataSource createDataSource() {
        // 创建连接池对象
        BasicDataSource dataSource = new BasicDataSource();
        // 设置连接参数
        dataSource.setUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUsername("root");
        dataSource.setPassword("password");
        // 设置连接池参数
        dataSource.setInitialSize(10);
        dataSource.setMaxTotal(100);
        dataSource.setMaxWaitMillis(10000);
        return dataSource;
    }
}

Problem 3: Connection timeout
Connection timeout means that the connection in the connection pool will be recycled if it is not used for a certain period of time, causing the connection Invalid. The following is a sample code for a solution:

public class ConnectionUtil {
    // 定义一个静态变量用于保存连接池对象
    private static DataSource dataSource;

    // 获取数据库连接
    public static Connection getConnection() throws SQLException {
        // 判断连接池是否已经初始化
        if (dataSource == null) {
            // 初始化连接池
            dataSource = createDataSource();
        }
        // 从连接池中获取连接
        Connection connection = dataSource.getConnection();
        // 设置连接超时时间
        connection.setNetworkTimeout(Executors.newFixedThreadPool(10), 5000);
        return connection;
    }

    // 释放数据库连接
    public static void releaseConnection(Connection connection) throws SQLException {
        // 判断连接是否为空
        if (connection != null) {
            // 关闭连接
            connection.close();
        }
    }

    // 创建连接池
    private static DataSource createDataSource() {
        // 创建连接池对象
        BasicDataSource dataSource = new BasicDataSource();
        // 设置连接参数
        dataSource.setUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUsername("root");
        dataSource.setPassword("password");
        // 设置连接池参数
        dataSource.setInitialSize(10);
        dataSource.setMaxTotal(100);
        dataSource.setMaxWaitMillis(10000);
        return dataSource;
    }
}

Summary:
In Java development, using a database connection pool is a common method to improve the efficiency and performance of database connections. However, we may also encounter problems such as database connection leaks, connection pool exhaustion, and connection timeouts during use. In response to these problems, we can take corresponding solutions to enhance the stability and availability of the connection pool. This article provides solutions to some common problems and code examples, hoping to be helpful to Java developers when using database connection pools.

The above is the detailed content of Common database connection pool problems and solutions in Java development. For more information, please follow other related articles on the PHP Chinese website!