Closing the Database Connection - con.close()

This section describes how to close database connections.

When you obtained a connection object with DriverManager.getConnection() successfully, you can create statement objects and execute them with this connection object. But when you are done with this connection, you should close it to free resources associated this connection on the SQL server. To close a connection, you should call the close() method on this connection object.

The tutorial program below shows you how to call close() on a connection object. isClosed() method is called to verify the status of the connection object.

 * Copyright (c) All Rights Reserved.
import java.sql.*;
public class CloseConnection {
  public static void main(String [] args) {
    Connection con = null;
    try {

// Obtaining a connection to SQL Server
      con = DriverManager.getConnection(
        + "user=herong;password=T0pSecret");

// Connection is ready to use
      DatabaseMetaData meta = con.getMetaData();
      System.out.println("Server name: "
        + meta.getDatabaseProductName());
      System.out.println("Server version: "
        + meta.getDatabaseProductVersion());

// Closing the connection
      if (con.isClosed())
        System.out.println("Connection closed.");

    } catch (Exception e) {

If you run this program, you will get:

herong> java -cp .;mssql-jdbc-9.4.1.jre16.jar

Server name: Microsoft SQL Server
Server version: 15.00.2000
Connection closed.

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 Microsoft SQL Server Express Edition

Microsoft JDBC Driver for SQL Server

 Installing Microsoft JDBC Driver for SQL Server

 Loading Driver Class Automatically

 Loading Driver Class with Class.forName()

 DriverManager.getConnection() and Connection URL

 Enable TCP/IP with SQL Server Configuration Manager

 Specifying Port Number in Connection URL

 Instance Name Better than Port Number

 Specifying Instance Name in Connection URL

Closing the Database Connection - con.close()

 Specifying Database Name in Connection URL

 Incorrect Database Name in Connection URL

 Creating Connections with DataSource Class

 Microsoft JDBC Driver - Query Statements and Result Sets

 Microsoft JDBC Driver - DatabaseMetaData Object

 Microsoft JDBC Driver - DDL Statements

 Microsoft JDBC Driver - DML Statements

 SQL Server - PreparedStatement

 SQL Server CLOB (Character Large Object) - TEXT

 SQL Server BLOB (Binary Large Object) - BLOB

 JDBC-ODBC Bridge Driver - sun.jdbc.odbc.JdbcOdbcDriver

 JDBC-ODBC Bridge Driver - Flat Text Files

 JDBC-ODBC Bridge Driver - MS Access

 JDBC-ODBC Bridge Driver - MS SQL Server

 Archived Tutorials


 Full Version in PDF/EPUB