Java – JDBC connection failed, error: TCP/IP connection to host failed

javajdbcsql server

I want to connect Java class file with SQL server 2012. I have logged in with SQL server authentication, but I am receiving an error when connecting.

Error:

The TCP/IP connection to the host 127.0.0.1, port 1433 has failed.
Error: "Connection refused: connect. Verify the connection properties.
Make sure that an instance of SQL Server is running on the host and
accepting TCP/IP connections at the port. Make sure that TCP
connections to the port are not blocked by a firewall.".

My code:

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");  //1. Register your driver
//2. get the connection object
//Connection con = DriverManager.getConnection("jdbc:sqlserver://localhost;databaseName=aysha","sa","admin");
Connection con = DriverManager.getConnection("jdbc:sqlserver://127.0.0.1;databaseName=aysha","user=sa","password=admin");
 //"jdbc:sqlserver://127.0.0.1:1433; Instance=SQL2008;" +       "databaseName=MB;user=sa;password=123;";
//Connection con = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=aysha","sa" , "password");
//3. Prepare a statement
Statement stmt = con.createStatement();
//4. Write the query`
String sql = "Select * from employee";
//5. Execute the statement and 
ResultSet rs = stmt.executeQuery(sql);
//6. Process the result set

while (rs.next())
{
    System.out.println(rs.getInt(1));
}

Best Answer

Open SQL Server Configuration Manager, and then expand SQL Server 2012 Network Configuration.
Click Protocols for InstanceName, and then make sure TCP/IP is enabled in the right panel and double-click TCP/IP.
On the Protocol tab, notice the value of the Listen All item.
Click the IP Addresses tab: If the value of Listen All is yes, the TCP/IP port number for this instance of SQL Server 2012 is the value of the TCP Dynamic Ports item under IPAll. If the value of Listen All is no, the TCP/IP port number for this instance of SQL Server 2012 is the value of the TCP Dynamic Ports item for a specific IP address.
Make sure the TCP Port is 1433.
Click OK.

Related Solutions

Java – JDBC Example for java

That's caused by many probabilities like 1- IP is worong 2- Port is wrong 3- There is firewall prevent machine to go out and connect to another IP 4- SQL server down .

try to use

    public class JdbcSQLServerDriverUrlExample
{
  public static void main(String[] args)
  {
    Connection connection = null;
    try
    {
      // the sql server driver string
      Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

      // the sql server url
      String url = "jdbc:microsoft:sqlserver://HOST:1433;DatabaseName=DATABASE";

      // get the sql server database connection
      connection = DriverManager.getConnection(url,"THE_USER", "THE_PASSWORD");

      // now do whatever you want to do with the connection
      // ...

    }
    catch (ClassNotFoundException e)
    {
      e.printStackTrace();
      System.exit(1);
    }
    catch (SQLException e)
    {
      e.printStackTrace();
      System.exit(2);
    }
  }
}

What i need to explain is there is very good technology called " Persistence " is better than JDBC and is more than brilliant and easy to use .

Java – JDBC connection Url for SQLServer express R2

Try running some Java code to test it. Replace {computer-name}\SQLEXPRESS with the domain that you see in the root node of SQL Server Management Studio. When installing SQL Express, you had the option to change the name of "SQLEXPRESS" to something custom, so that might also be different. To get the port number, go to Windows Start Menu > SQL Server 2008 R2 > Configuration Tools > SQL Server Configuration Manager > expand "SQL Server Network Configuration" > Click "Protocols for SQLEXPRESS" > right click "TCP/IP" and choose Properties > click "IP Addresses" tab/menu > in Windows XP, you will see "IPAll" .. look at the port there. It should default to 1433. If you have 2 version of SQL Express, then it might be different. Also make sure your service is running (has status of "Started") in Windows Control Panel > Administrative Tools > Services > SQL Server (SQLEXPRESS). Windows 7 is slightly different, but you'll find it.

The double backslashes need to be in a Java string. That just prints a single backslash during run time because it's an escape sequence.

import java.sql.*;

public class TestConnection
{
    public static void main(String[] args)
    {
        DB db = new DB();
        db.dbConnect("jdbc:sqlserver://{computer-name}\\SQLEXPRESS:1433;databaseName=abc;integratedSecurity=true;","sa","password");
    }
}

class DB
{
    public DB() {}

    public void dbConnect(String db_connect_string, String db_userid, String db_password)
    {
        try
        {
            Connection conn = DriverManager.getConnection(db_connect_string, db_userid, db_password);
            System.out.println("connected");
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
};

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