我正在尝试按照此处的教程使用 apache dbcp2 连接池连接到 mysql 数据库:
返回连接的我的数据库连接类如下所示:
public class DbConnection {
private static interface Singleton {
final DbConnection INSTANCE = new DbConnection();
}
private final PoolingDataSource<PoolableConnection> dataSource;
private DbConnection() {
// A ConnectionFactory that the pool will use to create Connections.
DriverManagerConnectionFactory connectionFactory = new DriverManagerConnectionFactory(url, user, pass); //url,user,pass for db connnection
//implement the pooling functionality.
PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory, null);
GenericObjectPoolConfig config = new GenericObjectPoolConfig();
config.setMaxWaitMillis(500);
config.setMaxTotal(20);
config.setMaxIdle(5);
config.setMinIdle(5);
//PoolingDataSource expect an ObjectPool
ObjectPool<PoolableConnection> connectionPool = new GenericObjectPool<>(poolableConnectionFactory, config);
// Set the poolableConnectionFactory's pool property to the owning pool
poolableConnectionFactory.setPool(connectionPool);
this.dataSource = new PoolingDataSource<>(connectionPool);
}
public static Connection getCon() throws SQLException {
return Singleton.INSTANCE.dataSource.getConnection();
}
}
我正在使用 apache jmeter 来测试连接并从我的 mysql 数据库返回一些内容。我创建了 100 个用户，启动周期(以秒为单位)为 2 秒。我创建了一个 Http 请求，当我尝试在查看结果树中查看我的响应时，我成功获得了前 20 个请求的响应。从 (21 到 100) 的后续请求有空白响应。我已经解决了许多问题，涉及:
java.sql.SQLException: Cannot get a connection, pool error Timeout waiting for idle object
我访问我的代码:
try (PreparedStatement ps = DbConnection.getCon().prepareStatement("SELECT id FROM test WHERE id =?;")) {
ps.setString(1, id);
try (
ResultSet rs = ps.executeQuery()) {
return rs.next();
}
} catch (Exception ex) {
}
最佳答案
您没有关闭 Connection 对象，您必须在 try-with-resources block 中声明此类变量:
try (Connection conn = DbConnection.getCon();
PreparedStatement ps = conn.prepareStatement("SELECT id FROM test WHERE id =?;")) {
此外，您还需要关闭ResultSet，可以在方法中调用close方法ResultSet，或者使用a将其添加到try-with-resources block 中返回它的新方法
关于java - Apache dbcp 连接池无法正常工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56412903/