We Keep Coding

How to connect to Oracle Database with JDBC [duplicate]

This question already has answers here:
java.net.ConnectException: Connection refused
(19 answers)
Closed 1 year ago.
I'm using Eclipse to connect to a remote database with the following details:
name: MSbdd**
Hostname 155.158.xxx.xx
Port: 1521
SID: olt*****
And the authentication type: Default
username: msbd**
password: haslo****
This is the code I have in Eclipse:
package net.codejava;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class JavaOracleTest {
public static void main(String[] args) {
String dbURL = "jdbc:oracle:thin:#localhost:1521:xe";
String username = "msbd**";
String password = "haslo****";
try {
Connection connection = DriverManager.getConnection(dbURL, username, password);
System.out.println("Połączono z serwerem Oracle");
} catch (SQLException e) {
System.out.println("Error");
e.printStackTrace();
}
}
}
And this is the error I get:
java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=yV+3U5v4TK2js7gMFTixxA==)
Error
at oracle.jdbc.driver.T4CConnection.handleLogonNetException(T4CConnection.java:882)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:687)
at oracle.jdbc.driver.PhysicalConnection.connect(PhysicalConnection.java:1086)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:90)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:728)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:649)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:677)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:228)
at net.codejava.JavaOracleTest.main(JavaOracleTest.java:15)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection (CONNECTION_ID=yV+3U5v4TK2js7gMFTixxA==)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:677)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:568)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:953)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:350)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:2155)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:652)
... 7 more
Caused by: java.io.IOException: Connection refused: connect, socket connect lapse 2003 ms. localhost 1521 0 (2/2) true
at oracle.net.nt.TcpNTAdapter.establishSocket(TcpNTAdapter.java:421)
at oracle.net.nt.TcpNTAdapter.doLocalDNSLookupConnect(TcpNTAdapter.java:303)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:265)
at oracle.net.nt.ConnOption.connect(ConnOption.java:238)
at oracle.net.nt.ConnStrategy.executeConnOption(ConnStrategy.java:902)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:638)
... 12 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.base/sun.nio.ch.Net.connect0(Native Method)
at java.base/sun.nio.ch.Net.connect(Net.java:482)
at java.base/sun.nio.ch.Net.connect(Net.java:474)
at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:694)
at java.base/java.nio.channels.SocketChannel.open(SocketChannel.java:194)
at oracle.net.nt.TimeoutSocketChannel.connect(TimeoutSocketChannel.java:184)
at oracle.net.nt.TimeoutSocketChannel.<init>(TimeoutSocketChannel.java:158)
at oracle.net.nt.TcpNTAdapter.establishSocket(TcpNTAdapter.java:380)
... 17 more
I've replaced some details with * because it's a database from school.

Your error is:
Caused by: java.net.ConnectException: Connection refused: connect
Check that you have:
The correct hostname.
For example, you say that the hostname is 155.158.xxx.xx but you are using:
String dbURL = "jdbc:oracle:thin:#localhost:1521:xe";
Should it be:
String dbURL = "jdbc:oracle:thin:#155.158.xxx.xx:1521:xe";
the correct port.
the correct SID.
For example, should it be:
String dbURL = "jdbc:oracle:thin:#155.158.xxx.xx:1521:olt*****";
the correct username and password.
access to the database.
I.e. you are running it on a network that can access the server and not from a network that cannot access the server (your school may require you to be directly connected to or logged in to their network to access the server and may refuse connections from unauthenticated users outside their network).

Not able to access one database in SQL Server using Java

I have an SQL Server 2012 edition. I have two databases on this server. One of these databases named BANKTEST was restored from a backup a few months ago. I have recently restored another database named NEWBANK.
The following is the java program which I had written to access NEWBANK
package com.example.myproject.client;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class ConnectMSSQL {
public static void main(String[] args) throws SQLException, ClassNotFoundException {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
Connection conn = DriverManager.getConnection("jdbc:sqlserver://127.0.0.1;user=sa;password=sa123;Database=NEWBANk");
System.out.println("test");
Statement sta = conn.createStatement();
String Sql = "select TOP 10 CodeType from D001002";
ResultSet rs = sta.executeQuery(Sql);
while (rs.next()) {
System.out.println(rs.getString("CodeType"));
}
}
}
Unfortunately, I am getting an error which I have listed below
> Exception in thread "main" com.microsoft.sqlserver.jdbc.SQLServerException: Cannot open database "NEWBANK" requested by the login. The login failed. ClientConnectionId:69c57dd7-38b1-413c-b8ea-8d53824f74e1
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:216)
at com.microsoft.sqlserver.jdbc.TDSTokenHandler.onEOF(tdsparser.java:254)
at com.microsoft.sqlserver.jdbc.TDSParser.parse(tdsparser.java:84)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.sendLogon(SQLServerConnection.java:2908)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(SQLServerConnection.java:2234)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.access$000(SQLServerConnection.java:41)
at com.microsoft.sqlserver.jdbc.SQLServerConnection$LogonCommand.doExecute(SQLServerConnection.java:2220)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:5696)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:1715)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1326)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:991)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:827)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:1012)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.example.myproject.client.ConnectMSSQL.main(ConnectMSSQL.java:13)
If I replace the name of the database with BANKTEST, I do not get any errors. Can someone advice me on this?
Regards
Sachin

The error shows that the username and password which you are using to login to your database NEWBANK is not valid or does not have the permision to access it.
You need to check your login details with your DBA and then try to login again. You can also check if you can access the database using the SQL Server Management Studio using the login credentails you are using in code.(You will probably find the same error over there as well)
You can also follow the steps given here: SQL SERVER – FIX : ERROR : Cannot open database requested by the login.
Go to SQL Server >> Security >> Logins and right click on NT
AUTHORITY\NETWORK SERVICE and select Properties
In newly opened screen of Login Properties, go to the “User Mapping”
tab. Then, on the “User Mapping” tab, select the desired database –
especially the database for which this error message is displayed. On
the lower screen, check the role db_owner. Click OK.

Connecting with hibernate to a Microsoft SQL 2008 server

I am trying to connect to a Microsoft SQL 2008 server via hibernate.
The following is my hibernate.cfg.xml file:
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.SQLServer2008Dialect</property>
<property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
<property name="connection.url">jdbc:sqlserver://127.0.0.1:1433;databaseName=myDBName;instanceName=myInstanceName;</property>
<property name="hibernate.connection.username">user</property>
<property name="hibernate.connection.password">pass</property>
<mapping resource="Obj.hbm.xml"/>
</session-factory>
</hibernate-configuration>
And here is the code I use to try and establish an connection and do a query :
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
public class SessionsTest {
private static SessionFactory sessionFactory;
private static ServiceRegistry serviceRegistry;
/**
* #param args
*/
#SuppressWarnings({ "unchecked"})
public static void main(String[] args) {
sessionFactory = configureSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
List<Obj> result = (List<Obj>) session.createQuery("FROM Obj").list();
for (Obj obj : result ) {
System.out.println(obj.getObjID());
}
session.getTransaction().commit();
session.close();
if ( sessionFactory != null ) {
sessionFactory.close();
}
}
private static SessionFactory configureSessionFactory() throws HibernateException {
Configuration config = new Configuration();
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
sessionFactory = config.buildSessionFactory(serviceRegistry);
return sessionFactory;
}
}
The stacktrace I get :
2013-04-13 15:02:03,449 [main] WARN org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 0, SQLState: 08S01
2013-04-13 15:02:03,449 [main] ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - The TCP/IP connection to the host 127.0.0.1, port 1433 has failed. Error: "Connection refused: connect. Verify the connection properties, check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port, and that no firewall is blocking TCP connections to the port.".
Exception in thread "main" org.hibernate.exception.JDBCConnectionException: Could not open connection
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:131)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:221)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:157)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1425)
at com.test.test.ObjTest.main(ObjTest.java:24)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host 127.0.0.1, port 1433 has failed. Error: "Connection refused: connect. Verify the connection properties, check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port, and that no firewall is blocking TCP connections to the port.".
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:171)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1033)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:817)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:700)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:842)
at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:204)
at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:292)
at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:214)
... 5 more
I have tried using a different driver(JTDS).
I have tried changing the URL string in various ways.
I have tried changing my dialect to org.hibernate.dialect.SQLServerDialect.
I also tried using windows authentication at one point by adding ;IntegratedSecurity=true to the end of the url string.
Other than this I have been poking around in the server properties to make sure the the instance I am providing is correct aswell as the port.I have tried : telnet localhost 1433 and can't connect that way,but I can connect using SQL Server Management Studio.
Further I used NetStat -o in cmd and TaskList /FI "PID eq 4072" /FO LIST /V to try and track down the sql server to confirm the port aswell.The weird thing is I couldn't track down sql server this way.It does not turn up in the NetStat list,but if I use the PID of the server directly it does show details about it except the Status is Unknown,Session# is 0 and User Name is N/A.
I use Hibernate 4.2.0 and SQLJDBC4,when I used JTDS it was 1.2.7.
The output of java -version :
java version "1.6.0_30"
Java(TM) SE Runtime Environment (build 1.6.0_30-b12)
Java HotSpot(TM) 64-Bit Server VM (build 20.5-b03, mixed mode)
Please tell me if any other info is needed,first time posting here.

I think your SQL Server instance is not serving at 1433 for TCP connections.
To identify the port:
Go to SQL Server configuration manager.
Choose SQL Server Network Configuration
Go for Protocols for Your Instance
Click on TCP IP (Enable it if not enabled, then clients could connect with TCP/IP)
On the popup which results, Choose IP Addresses Tab
Scroll Down
You'll see TCP Dynamic ports in Section IPAll
Grab that value and that's the port you should be using

Really, really, really check if the TCP/IP protocol is enabled in your SQL Server instance.
Follow these steps (tested for SS2012) to make sure:
Open "Sql Server Configuration Manager" in "Start Menu\Programs\Microsoft SQL Server 2012\Configuration Tools\"
Expand "SQL Server Network Configuration"
Go in "Protocols for <YourInstance>"
Enable TCP/IP
If you have any problem, check this blog post for details, as it contains screenshots and much more info.
Also check if the "SQL Server Browser" windows service is activated and running:
Go to Control Panel -> Administrative Tools -> Services
Open "SQL Server Browser" service and enable it (make it manual or automatic, depends on your needs)
Start it.
That's it.
After I installed a fresh local SQL Server, all I had to do was to enable TCP/IP and start the SQL Server Browser service.
Below a code I use to test the connection to a SQLEXPRESS local instance. Of course, you should change the IP, DatabaseName and user/password as needed.:
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JtdsSqlExpressInstanceConnect {
public static void main(String[] args) throws SQLException {
Connection conn = null;
ResultSet rs = null;
String url = "jdbc:jtds:sqlserver://127.0.0.1;instance=SQLEXPRESS;DatabaseName=master";
String driver = "net.sourceforge.jtds.jdbc.Driver";
String userName = "user";
String password = "password";
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, userName, password);
System.out.println("Connected to the database!!! Getting table list...");
DatabaseMetaData dbm = conn.getMetaData();
rs = dbm.getTables(null, null, "%", new String[] { "TABLE" });
while (rs.next()) { System.out.println(rs.getString("TABLE_NAME")); }
} catch (Exception e) {
e.printStackTrace();
} finally {
conn.close();
rs.close();
}
}
}
And if you use Maven, add this to your pom.xml:
<dependency>
<groupId>net.sourceforge.jtds</groupId>
<artifactId>jtds</artifactId>
<version>1.2.4</version>
</dependency>

Create a jTDS connection string

my sql server instance name is MYPC\SQLEXPRESS and I'm trying to create a jTDS connection string to connect to the database 'Blog'. Can anyone please help me accomplish that?
I'm trying to do like this:
DriverManager.getConnection("jdbc:jtds:sqlserver://127.0.0.1:1433/Blog", "user", "password");
and I get this:
java.sql.SQLException: Network error IOException: Connection refused: connect
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.<init>(ConnectionJDBC2.java:395)
at net.sourceforge.jtds.jdbc.ConnectionJDBC3.<init>(ConnectionJDBC3.java:50)
at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:184)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at SqlConnection.Connect(SqlConnection.java:19)
at main.main(main.java:11)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.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 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.sourceforge.jtds.jdbc.SharedSocket.createSocketForJDBC3(SharedSocket.java:305)
at net.sourceforge.jtds.jdbc.SharedSocket.<init>(SharedSocket.java:255)
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.<init>(ConnectionJDBC2.java:323)
... 6 more

As detailed in the jTDS Frequenlty Asked Questions, the URL format for jTDS is:
jdbc:jtds:<server_type>://<server>[:<port>][/<database>][;<property>=<value>[;...]]
So, to connect to a database called "Blog" hosted by a MS SQL Server running on MYPC, you may end up with something like this:
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS;user=sa;password=s3cr3t
Or, if you prefer to use getConnection(url, "sa", "s3cr3t"):
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS
EDIT: Regarding your Connection refused error, double check that you're running SQL Server on port 1433, that the service is running and that you don't have a firewall blocking incoming connections.

Really, really, really check if the TCP/IP protocol is enabled in your local SQLEXPRESS instance.
Follow these steps to make sure:
Open "Sql Server Configuration Manager" in "Start Menu\Programs\Microsoft SQL Server 2012\Configuration Tools\"
Expand "SQL Server Network Configuration"
Go in "Protocols for SQLEXPRESS"
Enable TCP/IP
If you have any problem, check this blog post for details, as it contains screenshots and much more info.
Also check if the "SQL Server Browser" windows service is activated and running:
Go to Control Panel -> Administrative Tools -> Services
Open "SQL Server Browser" service and enable it (make it manual or automatic, depends on your needs)
Start it.
That's it.
After I installed a fresh local SQLExpress, all I had to do was to enable TCP/IP and start the SQL Server Browser service.
Below a code I use to test the SQLEXPRESS local connection. Of course, you should change the IP, DatabaseName and user/password as needed.:
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JtdsSqlExpressInstanceConnect {
public static void main(String[] args) throws SQLException {
Connection conn = null;
ResultSet rs = null;
String url = "jdbc:jtds:sqlserver://127.0.0.1;instance=SQLEXPRESS;DatabaseName=master";
String driver = "net.sourceforge.jtds.jdbc.Driver";
String userName = "user";
String password = "password";
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, userName, password);
System.out.println("Connected to the database!!! Getting table list...");
DatabaseMetaData dbm = conn.getMetaData();
rs = dbm.getTables(null, null, "%", new String[] { "TABLE" });
while (rs.next()) { System.out.println(rs.getString("TABLE_NAME")); }
} catch (Exception e) {
e.printStackTrace();
} finally {
conn.close();
rs.close();
}
}
}
And if you use Maven, add this to your pom.xml:
<dependency>
<groupId>net.sourceforge.jtds</groupId>
<artifactId>jtds</artifactId>
<version>1.2.4</version>
</dependency>

jdbc:jtds:sqlserver://x.x.x.x/database replacing x.x.x.x with the IP or hostname of your SQL Server machine.
jdbc:jtds:sqlserver://MYPC/Blog;instance=SQLEXPRESS
or
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS
If you are wanting to set the username and password in the connection string too instead of against a connection object separately:
jdbc:jtds:sqlserver://MYPC/Blog;instance=SQLEXPRESS;user=foo;password=bar
(Updated my incorrect information and add reference to the instance syntax)

A shot in the dark, but
From the looks of your error message, it seems that either the sqlserver instance is not running on port 1433 or something is blocking the requests to that port

SQLServer runs the default instance over port 1433. If you specify the port as port 1433, SQLServer will only look for the default instance. The name of the default instance was created at setup and usually is SQLEXPRESSxxx_xx_ENU.
The instance name also matches the folder name created in Program Files -> Microsoft SQL Server. So if you look there and see one folder named SQLEXPRESSxxx_xx_ENU it is the default instance.
Folders named MSSQL12.myInstanceName (for SQLServer 2012) are named instances in SQL Server and are not accessed via port 1433.
So if your program is accessing a default instance in the database, specify port 1433, and you may not need to specify the instance name.
If your program is accessing a named instance (not the default instance) in the database DO NOT specify the port but you must specify the instance name.
I hope this clarifies some of the confusion emanating from the errors above.

ORA-12505 :TNS listener does not currently know of SID given in connect descriptor

I am using Oracle database. I've written a small JDBC connection program in Java but I am facing an issue with the listener.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JdbcConnection {
public static void main(String[] args) throws SQLException,ClassNotFoundException {
String url = "jdbc:oracle:thin:#localhost:1521:orcl";
String user = "system";
String password = "password";
Connection connection = null;
Class.forName("oracle.jdbc.driver.OracleDriver");
connection = DriverManager.getConnection(url, user, password);
if(connection!=null){
System.out.println("Success in connnection");
} else {
System.out.println("failure in connection ");
}
}
}
I am getting the following exception:
C:\Users\Administrator\Desktop>java JdbcConnection
Exception in thread "main" java.sql.SQLException: Listener refused the connectio
n with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
localhost:1521:orcl
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java
:112)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java
:261)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:
441)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtensio
n.java:35)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at JdbcConnection.main(JdbcConnection.java:18)
This is the output of lsnrctl status
LSNRCTL for 64-bit Windows: Version 12.1.0.1.0 - Production on 16-JUN-2015 13:43
:41
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Welcome to LSNRCTL, type "help" for information.
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 64-bit Windows: Version 12.1.0.1.0 - Produ
ction
Start Date 16-JUN-2015 12:02:52
Uptime 0 days 1 hr. 40 min. 52 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File C:\app\orauser\product\12.1.0\dbhome_1\network\admin\l
istener.ora
Listener Log File C:\app\orauser\diag\tnslsnr\hydwemvm\listener\alert\lo
g.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=hydwemvm)(PORT=1521)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

If you know your oracle database SID, then use
jdbc:oracle:thin:#localhost:1521:orcl
otherwise use below in case you have service name
jdbc:oracle:thin:#localhost:1521/orcl
Also, make sure service name with the name ORCL should be up and running. If still doesn't work, then you need to restart your machine and try again above.
Still, not working ? Then, try following :
Login with SYSTEM user and register LOCAL_LISTENER by running below SQLs.
alter system set local_listener = '(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))' scope = both;
alter system register;
How to check oracle SID and service name :
SELECT sys_context('USERENV', 'SID') FROM DUAL; -- It will return your oracle database SID
SELECT sys_context('USERENV', 'SERVICE_NAME') FROM DUAL; -- It will return your oracle database service name

If you want to know the default SID of your database use this query in sqlplus:
SELECT sys_context('USERENV', 'SID') FROM DUAL;
Use this value in the JDBC URL instead of "orcl".

Can you use the below URL?
Note the difference, this is to use the SERVICENAME instead of a SID.
jdbc:oracle:thin:#localhost:1521/orclservice

I am facing the same problem.
Try removing the LAN cable or disconnect your net connectivity and
restart the services of Listener and run the code.
It worked for me.