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H2 Database connection timeout with new computer

I'm using two H2 databases in my Java projects. Recently, I changed my computer and since then I have no problem with connecting to one of those databases using my Java code but problems with the other one. It's exactly the same code (up to PATH_TO_DATABASE) I use to start the connection:
import java.sql.DriverManager;
import java.sql.SQLException;
public class DatabaseConfig {
private static java.sql.Connection connection;
public static void init() {
if (connection == null) {
try {
connection = DriverManager.getConnection("jdbc:h2:tcp://192.168.178.50:9092/C:/Users/PATH_TO_DATABASE", "USER", "PW");
} catch (SQLException e) {
System.err.println("SQLException");
e.printStackTrace();
System.exit(0);
}
}
}
[...]
}
This is the stack trace I get:
SQLException
org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.SocketTimeoutException: connect timed out: 192.168.178.21:9092" [90067-196]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
at org.h2.message.DbException.get(DbException.java:168)
at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:457)
at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:334)
at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:116)
at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:100)
at org.h2.Driver.connect(Driver.java:69)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at data.DatabaseConfig.init(DatabaseConfig.java:20)
...
Caused by: java.net.SocketTimeoutException: connect timed out
at java.net.DualStackPlainSocketImpl.waitForConnect(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.h2.util.NetUtils.createSocket(NetUtils.java:103)
at org.h2.util.NetUtils.createSocket(NetUtils.java:83)
at org.h2.engine.SessionRemote.initTransfer(SessionRemote.java:115)
at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:453)
... 8 more
Using the web interface I can connect to both databases easily.
I'm a little bit lost here since I can't figure out what's going wrong with one of the databases. The strange thing is that everything works fine with the other database.
EDIT: I just realized that the IP address in the error message is different from the one in the code (192.168.178.21:9092 vs. 192.168.178.50:9092). Maybe this is th ereason of the error. The one in the code is the correct IP address. Why do I get a different one in the error message? Is that the reason of my problem?

If it's a remote connection, do an ipconfig to find out if the 192.168.x.x. address is changed.
If it's a local connection, you can simplify your URL as
jdbc:h2:~/PATH_TO_DATABASE

I just solved the problem (it was kind of my stupidity): The project couldn't build on the new computer because the H2 jar was not properly included in the build path. That's why eclipse called all the time the old .class file and hence tried to connect to the old computer (192.168.178.21:9092) instead to the new one (192.168.178.50:9092). I didn't realize that eclipse didn't compile and was executing old stuff.

How to connect DB2 database connectivity using java ?

Am trying to connect DB2 database in java but it throwing error, I can't find what issue was that. I added db2jcc.jar and here I show my complete database connectivity code.
public class ConnectionExample {
public static void main(String[] args) {
String jdbcClassName="com.ibm.db2.jcc.DB2Driver";
String url="jdbc:db2://localhost:50000/TestDb";
String user="user";
String password="pass#123";
Connection connection = null;
try {
//Load class into memory
Class.forName(jdbcClassName);
//Establish connection
connection = DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}finally{
if(connection!=null){
System.out.println("Connected successfully.");
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
}
Am trying to connect DB2 database with the above code but it throws error.
com.ibm.db2.jcc.am.DisconnectNonTransientConnectionException: [jcc][t4][2043][11550][3.63.123] Exception java.net.ConnectException: Error opening socket to server localhost/127.0.0.1 on port 50,000 with message: Connection refused: connect. ERRORCODE=-4499, SQLSTATE=08001
at com.ibm.db2.jcc.am.fd.a(fd.java:321)
at com.ibm.db2.jcc.am.fd.a(fd.java:340)
at com.ibm.db2.jcc.t4.xb.a(xb.java:433)
at com.ibm.db2.jcc.t4.xb.<init>(xb.java:90)
at com.ibm.db2.jcc.t4.a.z(a.java:347)
at com.ibm.db2.jcc.t4.b.a(b.java:1974)
at com.ibm.db2.jcc.am.ib.a(ib.java:691)
at com.ibm.db2.jcc.am.ib.<init>(ib.java:644)
at com.ibm.db2.jcc.t4.b.<init>(b.java:330)
at com.ibm.db2.jcc.DB2SimpleDataSource.getConnection(DB2SimpleDataSource.java:231)
at com.ibm.db2.jcc.DB2SimpleDataSource.getConnection(DB2SimpleDataSource.java:197)
at com.ibm.db2.jcc.DB2Driver.connect(DB2Driver.java:472)
at com.ibm.db2.jcc.DB2Driver.connect(DB2Driver.java:113)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at ConnectionExample.main(ConnectionExample.java:18)
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 com.ibm.db2.jcc.t4.x.run(x.java:38)
at java.security.AccessController.doPrivileged(Native Method)
at com.ibm.db2.jcc.t4.xb.a(xb.java:419)
... 13 more
Hope Someone helps me to find out the solution. Thanks

Actually the port 50000 is not opened that is the reason I got the error after change that port to 51020 it works fine also it connects with database.
String url="jdbc:db2://localhost:51020/TestDb";
Thanks

Cause
A possible cause for this problem is that TCP/IP is not properly enabled on your DB2 database server.
Resolving the problem
Use the db2set DB2COMM command from the DB2 command window to start the TCP/IP connection:
db2set DB2COMM=protocol_names
For example, to set the database manager to start connection managers for the TCP/IP communication protocols, enter the following commands:
db2set DB2COMM=tcpip
db2stop
db2start
Source: https://www-304.ibm.com/support/docview.wss?uid=swg21403644

I found a net connection error while using localhost in jdbc

I wrote this program to connect with my database which is on the same computer but i found a net connection error each time. com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
import java.sql.*;
public class Demo {
public static void main(String[] args) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/db","username","pwd");
Statement stmt = connection.createStatement();
String str="SHOW TABLES";
ResultSet resultSet=stmt.executeQuery(str);
while (resultSet.next()) {
System.out.println(resultSet.getString(1));
}
}catch(Exception e){
e.printStackTrace();
}
}
}
My Stacktrace is:-
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.ConnectException
MESSAGE: Connection refused: connect
STACKTRACE:
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 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:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2771)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at Demo.main(Demo.java:8)
** END NESTED EXCEPTION **
Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2847)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at Demo.main(Demo.java:8)

Try this:
DriverManager.getConnection("jdbc:mysql://localhost:3306/dbname","username","password");
If this is not sorted out go to where you installed Mysql and open MySQL Notifier and check server is running or not if not start it and then try executing your program.

This error was mainly due to Mysql server not reachable or not running. Check with below points:
1. Check your DB Connection whether MYSQL is up and running.
2. Check if you are able to connect from command prompt
3. Restart the mysql server and try again.

Database not found error when connecting to Derby network server

I'm having problems initializing my javadb network server and setting a connection to it. It's a JavaFX program.
This is what I have so far:
try {
Class.forName("org.apache.derby.jdbc.ClientDriver").newInstance();
javadbserver = new NetworkServerControl();
javadbserver.start(null);
} catch (ClassNotFoundException e) {
Logger.getLogger(MainGuiController.class.getName()).log(Level.SEVERE, null, ex);
System.out.println("Where is your JavaDB embedded Driver?");
return;
}
String dbName = "mydb";
String dbUser = "auser";
String dbPass = "password";
PreparedStatement prepstmt;
try {
this.conn = DriverManager.getConnection("jdbc:derby://localhost:1527/mydb;user=auser;password=password");
System.out.println("Went through!");
} catch (SQLException ex) {
Logger.getLogger(MainGuiController.class.getName()).log(Level.SEVERE, null, ex);
}
I always catch the second exception.
If I right click on the javadb service in netbeans and choose connect, everything runs smoothly. [Actually it'd be nice to know what code or program java runs in the background when I select that]
In my projects list under libraries I see derby.jar, derbyclient.jar and derbynet.jar
What am I doing wrong? Please help!
Here's the error I get
java.sql.SQLNonTransientConnectionException: The connection was refused because the database mydb was not found.
at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.jdbc.ClientDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:579)
at java.sql.DriverManager.getConnection(DriverManager.java:243)
at mydb.MainGuiController.initialize(MainGuiController.java:105)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2152)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2028)
at mydb.mydb.start(mydb.java:37)
at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:215)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:176)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:176)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:73)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.apache.derby.client.am.DisconnectException: The connection was refused because the database mydb was not found.
at org.apache.derby.client.net.NetConnectionReply.parseRDBNFNRM(Unknown Source)
at org.apache.derby.client.net.NetConnectionReply.parseAccessRdbError(Unknown Source)
at org.apache.derby.client.net.NetConnectionReply.parseACCRDBreply(Unknown Source)
at org.apache.derby.client.net.NetConnectionReply.readAccessDatabase(Unknown Source)
at org.apache.derby.client.net.NetConnection.readSecurityCheckAndAccessRdb(Unknown Source)
at org.apache.derby.client.net.NetConnection.flowSecurityCheckAndAccessRdb(Unknown Source)
at org.apache.derby.client.net.NetConnection.flowUSRIDPWDconnect(Unknown Source)
at org.apache.derby.client.net.NetConnection.flowConnect(Unknown Source)
at org.apache.derby.client.net.NetConnection.<init>(Unknown Source)
at org.apache.derby.client.net.NetConnection40.<init>(Unknown Source)
at org.apache.derby.client.net.ClientJDBCObjectFactoryImpl40.newNetConnection(Unknown Source)

By the JDBC url, it's looks like you're trying to connect to a Derby server vs. an embedded instance. If you are trying to connect to a server instance, here are some considerations:
did you start the server yourself, did mydb already exists?
if not, did you pass in the correct params to create (e.g. ;create=true)
example: jdbc:derby://localhost:1527/dbname;create=true
if mydb did exists, are you pointing the server to the correct location?
also, depending on what was used to start derby (e.g. embedded vs network driver) default database locations are different as well. You can read about it here
Basically the exception you're getting is that Derby's saying it can't find your database - it's basically a path issue.

If you're using netbeans, you should fix this by going into the connection properties and adding a property. Under "property" type "create" and under "value" type "true".

JDBC | SQL Server connection error

I'm trying to generate some reports to my system using Jasper reports. I'm suing basic JDBC connection method to establish a connection to my SQL Server 2000. Here is my code snippet:
public static Connection getConnection()throws ClassNotFoundException, SQLException
{
Class.forName(driver);
Connection conn = DriverManager.getConnection(connectString, user, password);
return conn;
}
But I'm getting a SQL incorrect syntax exception.
Caused by: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]Line 2: Incorrect syntax near '|'.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processErrorToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processReplyToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSExecuteRequest.processReplyToken(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processReply(Unknown Source)
at com.microsoft.jdbc.sqlserver.SQLServerImplStatement.getNextResultType(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.commonTransitionToState(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.postImplExecute(Unknown Source)
at com.microsoft.jdbc.base.BasePreparedStatement.postImplExecute(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.commonExecute(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.executeQueryInternal(Unknown Source)
at com.microsoft.jdbc.base.BasePreparedStatement.executeQuery(Unknown Source)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:478)
Thanks.

The first line of the exception you get says:
Line 2: Incorrect syntax near '|'.
Check to see where you have the '|' in your source. In case of doubt try these:
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433", user, password);
Make also sure your jars are at the right place.