Develop Reference

Java issue within connection to Microsoft SQL Server

How can I connect to Microsoft SQL Server from my java code?
Code:
public class insert {
public static void main(String[] args) {
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
String url = "jdbc:microsoft:sqlserver://LENOVO-PC\\SQLEXPRESS;DatabaseName=dbtest";
Connection connection = DriverManager.getConnection(url , "sa" , "Aa123456");
Statement st = connection.createStatement();
st.executeUpdate("INSERT INTO [dbo].[table] VALUES ('come')");
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
System.exit(1);
}
catch (SQLException e)
{
e.printStackTrace();
System.exit(2);
}
}
}
Error:
java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at insert.main(insert.java:12)
Microsoft SQL Server name is: LENOVO-PC\SQLEXPRESS
and sqljdbc.jar is already added to the referenced libraries.

The class name com.microsoft.jdbc.sqlserver.SQLServerDriver you're trying to load is from a very old version of the Microsoft SQL Server 2000 version of the driver. Around 2005, Microsoft changed this to com.microsoft.sqlserver.jdbc.SQLServerDriver (notice the switch in order between jdbc and sqlserver). At that time, they also changed the driver URL prefix from jdbc:microsoft:sqlserver: to jdbc:sqlserver:.
In other words, you need to:
Use Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver") (optional, driver will be loaded automatically)
Change your URL to jdbc:sqlserver://LENOVO-PC\\SQLEXPRESS;databaseName=dbtest (note the prefix change and DatabaseName -> databaseName. See also Building the Connection URL.
With recent JDBC drivers, it is not necessary to explicitly load the driver class in simple Java applications, so instead of step 1, you could also remove the Class.forName line.
Also make sure you are using a recent version of the driver, see the mssql-jdbc project on GitHub (latest stable version at time of writing is 7.0.0).

Correct the driver class name:
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

Connection between a Java application and a database on Cloudera

as the title, I have a problem with the connection between a Java application and the database created on a virtual machine Cloudera.
A sample project application, which I placed, contains files with the extension .jar needed to connect.
Virtual machine network card is set to Host-Only.
Ip this virtual machine: 192.168.56.1.
I have no idea what to do next in order to be able to perform queries to the database.
Please help and sorry for my English.
Java Code:
package p;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.util.Scanner;
public class p{
static Connection connection = null;
static Statement statement = null;
public static void main(String[] args) throws SQLException, ClassNotFoundException {
Class.forName("com.cloudera.hive.jdbc4.HS2Driver");
connection = DriverManager.getConnection("jdbc:hive2://192.168.56.1:10000/przychodnia", "cloudera", "cloudera");
statement = connection.createStatement();
System.out.println("Wybierz");
System.out.println("0 aby dodać do istniejącej tabeli wiersz");
System.out.println("1 aby usunąć z istniejącej tabeli wiersz");
String SQL = "SELECT * FROM pacjenci";
ResultSet rs = statement.executeQuery(SQL);
while (rs.next()){
String imie = rs.getString("imie");
String p = imie;
System.out.println(p);
}
}
}
Warnings:
log4j:WARN No appenders could be found for logger (org.apache.thrift.transport.TSaslTransport).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.sql.SQLException: [Simba][HiveJDBCDriver](500310) Invalid operation: java.net.ConnectException: Connection refused: connect;
at com.cloudera.hive.hivecommon.api.HiveServer2ClientFactory.createTransport(HiveServer2ClientFactory.java:224)
at com.cloudera.hive.hive.api.ExtendedHS2Factory.createClient(ExtendedHS2Factory.java:38)
at com.cloudera.hive.hivecommon.core.HiveJDBCConnection.connect(HiveJDBCConnection.java:597)
at com.cloudera.hive.jdbc.common.BaseConnectionFactory.doConnect(BaseConnectionFactory.java:219)
at com.cloudera.hive.jdbc.common.AbstractDriver.connect(AbstractDriver.java:216)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
Caused by: com.cloudera.hive.support.exceptions.GeneralException: [Simba][HiveJDBCDriver](500310) Invalid operation: java.net.ConnectException: Connection refused: connect;
... 7 more
Caused by: org.apache.thrift.transport.TTransportException: java.net.ConnectException: Connection refused: connect
at org.apache.thrift.transport.TSocket.open(TSocket.java:185)
at org.apache.thrift.transport.TSaslTransport.open(TSaslTransport.java:248)
at org.apache.thrift.transport.TSaslClientTransport.open(TSaslClientTransport.java:37)
at com.cloudera.hive.hivecommon.api.HiveServer2ClientFactory.createTransport(HiveServer2ClientFactory.java:210)
at com.cloudera.hive.hive.api.ExtendedHS2Factory.createClient(ExtendedHS2Factory.java:38)
at com.cloudera.hive.hivecommon.core.HiveJDBCConnection.connect(HiveJDBCConnection.java:597)
at com.cloudera.hive.jdbc.common.BaseConnectionFactory.doConnect(BaseConnectionFactory.java:219)
at com.cloudera.hive.jdbc.common.AbstractDriver.connect(AbstractDriver.java:216)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at p.p.main(p.java:15)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at org.apache.thrift.transport.TSocket.open(TSocket.java:180)
... 10 more

Ip this virtual machine: 192.168.56.1.
Your image that says "Column name not found" is using IP 192.168.56.101

Communications link failure when connecting to remote MySQL database

I'm trying to make a Java program communicate with a MySQL server hosted with A Small Orange. The IP and port they provided me with are 129.121.106.234:3306. The user has been given full permissions to the database, and in my CPanel I've allowed all remote hosts to connect to the MySQL database by adding the access host "%".
I'm using Eclipse, and I've downloaded and added the JDBC driver to the build path.
As near as I can tell, the user I'm trying to use has full permissions to the database, and the MySQL server is open to any request from any IP. I've also tried my admin MySQL credentials, with the same error, so I'm decently confident the issue is with my code. Not absolutely sure though, since I'm not hosting the MySQL server myself.
My code:
package com.package.IPBounce;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Main {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
/*
* Isaac the Support Ninja says: The MySQL port is 3306. The IP you use
* is 129.121.106.234.
*/
URL whatismyip;
String IP;
try {
whatismyip = new URL("http://checkip.amazonaws.com");
BufferedReader in = new BufferedReader(new InputStreamReader(
whatismyip.openStream()));
IP = in.readLine();
System.out.println(IP);
Connection con = null;
Statement st = null;
ResultSet rs = null;
//this is just testing code until I get the connection working
String url = "jdbc:mysql://129.121.106.234:3306/db_name";
String user = "user_name";
String password = "small_password";
Class.forName("com.mysql.jdbc.Driver").newInstance();
con = DriverManager.getConnection(url, user, password);//error is on this line
st = con.createStatement();
rs = st.executeQuery("SELECT VERSION()");
if (rs.next()) {
System.out.println(rs.getString(1));
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
The error text:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1137)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:356)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2504)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2541)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2323)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.package.IPBounce.Main.main(Main.java:39)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:258)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:306)
... 15 more
Edit: I found the solution. My hosting service was blocking the MySQL requests at the firewall. Cleared that up, now it works wonderfully.

The only thing I see as a possible issue is the "newInstance()" call. Try remove that and see if that works.
From:
Class.forName("com.mysql.jdbc.Driver").newInstance();
To:
Class.forName("com.mysql.jdbc.Driver");

This question has been answered here:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
Please try the steps in the accepted answer and see if your issue is resolved.
From my experience, I had this issue when my MySql configuration file allowed only localhost access. Replace localhost with the ip address.

Error in connecting oracle 11G in localhost using JDBC

import java.sql.*;
public class one {
public static void main(String[] args)
{
Connection conn=null;
Statement stmt=null;
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
conn=DriverManager.getConnection("jdbc:oracle:thin:#//localhost:1521/ecom","system","manager");
stmt=conn.createStatement();
String str="insert into country values(3,'bangladesh');";
int k=stmt.executeUpdate(str);
System.out.println(k);
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
The only jar file I added to the class path is ojdbc6.jar is there any other jar required for connecting with oracle 11g(11.2.0.1.0) I am using eclipse as IDE
here are the errors
java.sql.SQLException: The Network Adapter could not establish the connection
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at one.main(one.java:17)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:359)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:422)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:672)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:237)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
... 7 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocket`Impl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:141)

1) Please be sure database host name, port number, or database instance name are correct.
2) Be sure the TNSListener has been started ( run lsnrctl start)

The connection string is malformed. It should be
"jdbc:oracle:thin://#localhost:1521/ecom"
Notice the transposition of // and #.

MySQL jdbc driver and Eclipse problems

I am having problems loading the MySQL JDBC driver. I have tried everything mentioned here, but am still running into problems.
The error I get is this:
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.driver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at Main.main(Main.java:12)
My code is as follows:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class Main {
public static void main(String args[]) throws Exception {
//accessing the driver
Class.forName("com.mysql.jdbc.driver");
// creating variable to pass the connection information into
Connection dbcon = DriverManager.getConnection(
"jdbc:mysql//localhost:3306/test", "root", "root");
PreparedStatement statement = dbcon
.prepareStatement("select * from names");
ResultSet result = statement.executeQuery();
while (result.next()) {
System.out.println(result.getString(2));
}
}
}
As you can see above I have placed the driver in the lib folder and I have also put it into the Apache tomcat lib folder, because that was suggested as well.
Thank you for any help you can give me.
Andrew

The class name inside the MySql connectorJ JAR file is Driver. so you need to change
Class.forName("com.mysql.jdbc.driver");
to
Class.forName("com.mysql.jdbc.Driver");

It tells you the problem on the first line of your stacktrace:
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.driver
The driver name is com.mysql.jdbc.Driver (capital D).

problem in loading the mysql connection library.please check the proper mysql library is load successfully.because when library load successfully then the library package display all the external loaded library.