I am trying to connect from Java program to impala using the below driver
com.cloudera.impala.jdbc4.Driver
but i am getting a sql exception, bellow stack-trace
java.sql.SQLException: [Simba][ImpalaJDBCDriver](500310) Invalid operation: java.net.ConnectException: Connection refused: connect;
at com.cloudera.impala.hivecommon.api.HiveServer2ClientFactory.createTransport(HiveServer2ClientFactory.java:224)
at com.cloudera.impala.hivecommon.api.HiveServer2ClientFactory.createClient(HiveServer2ClientFactory.java:52)
at com.cloudera.impala.hivecommon.core.HiveJDBCConnection.connect(HiveJDBCConnection.java:597)
at com.cloudera.impala.jdbc.common.BaseConnectionFactory.doConnect(BaseConnectionFactory.java:219)
at com.cloudera.impala.jdbc.common.AbstractDriver.connect(AbstractDriver.java:216)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.gcs.virdict.InsertImpala.generateValue(InsertImpala.java:86)
Caused by: com.cloudera.impala.support.exceptions.GeneralException: [Simba][ImpalaJDBCDriver](500310) Invalid operation: java.net.ConnectException: Connection refused: connect;
I am also attaching the code below for reference
private void connectionImpala() {
try {
Class.forName(IMPALA_DRIVER_NAME);
} catch (ClassNotFoundException e) {
e.printStackTrace();
System.exit(1);
}
Connection con = null;
Statement stmt = null;
try {
con = DriverManager.getConnection( "jdbc:impala://IP:21050/default;user=abcde;password=abcde");
stmt = con.createStatement();
// ResultSet rs = stmt.executeQuery(sqlStatement)
} catch (SQLException e) {
e.printStackTrace();
}
Related
I'm fairly new at developing apps. I've began a tutorial on how to connect an app to a database using JDBC driver. I'm using Android Studio and MySQL Workbench.
Here is a sample of the code:
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbtest", "root", "123");
stmt = conn.createStatement();
String query = "SELECT * from tblHockeyPlayers";
ResultSet rs = stmt.executeQuery(query);
while(rs.next()){
String name = rs.getString("name");
double number = rs.getDouble("number");
hockeyPlayersMap.put(name, number);
}
msg = "Process successful.";
rs.close();
stmt.close();
conn.close();
} catch (SQLException connError) {
msg = "An exception was thrown for JDBC";
connError.printStackTrace();
} catch (ClassNotFoundException e) {
msg = "A class not found exception was thrown";
e.printStackTrace();
} finally {
try {
if (stmt != null){
stmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
if (conn != null){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
The line conn = DriverManager.getConnection(DB_URL, DbStrings.USERNAME, DbStrings.PASSWORD); always triggers this error (catches an SQLException):
java.sql.SQLException: Unable to connect to any hosts due to exception: java.net.SocketException: java.net.ConnectException: failed to connect to /127.0.0.1 (port 3306) from /:: (port 35618): connect failed: ECONNREFUSED (Connection refused)
** BEGIN NESTED EXCEPTION **
java.net.SocketException
MESSAGE: java.net.ConnectException: failed to connect to /127.0.0.1 (port 3306) from /:: (port 35618): connect failed: ECONNREFUSED (Connection refused)
STACKTRACE:
java.net.SocketException: java.net.ConnectException: failed to connect to /127.0.0.1 (port 3306) from /:: (port 35618): connect failed: ECONNREFUSED (Connection refused)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:143)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:225)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1805)
at com.mysql.jdbc.Connection.<init>(Connection.java:452)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:411)
at java.sql.DriverManager.getConnection(DriverManager.java:569)
at java.sql.DriverManager.getConnection(DriverManager.java:219)
at com.sportsknowledge.mysqlexampleproject.MainActivity$GetData.doInBackground(MainActivity.java:69)
at com.sportsknowledge.mysqlexampleproject.MainActivity$GetData.doInBackground(MainActivity.java:50)
at android.os.AsyncTask$2.call(AsyncTask.java:333)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
** END NESTED EXCEPTION **
I have tried to use XAMMP and EasyPHP and read all sort of things that didn't work out. I don't know what else to try.
I am having connection issues with my java program interacting with oracle 11g using ojdbc7.jar. I am using jdk 1.8 on windows 7 platform. I'm getting an error with the connection.
I'm writing my whole program below:
package mydao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class AdminDAO {
Connection con;
public void connectionMethod() {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
con = DriverManager.getConnection("jdbc:oracle:thin:#localhost:1521:oracleEE", "system", "tiger");
} catch (ClassNotFoundException cnfe) {
cnfe.printStackTrace();
} catch (SQLException sqle) {
sqle.printStackTrace();
}
}
public void loginCheck(String uid, String pwd) {
connectionMethod();
try {
String sql = "SELECT * FROM ADMIN_LOGIN WHERE ADMINUID=? AND ADMINPWD=?";
PreparedStatement ps = con.prepareStatement(sql);
ps.setString(1, uid);
ps.setString(2, pwd);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
rs.getString(1);
rs.getString(2);
rs.getString(3);
}
} catch (SQLException sqle) {
sqle.printStackTrace();
} finally {
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
AdminDAO a = new AdminDAO();
a.loginCheck("avi", "avi3");
}
}
But I'm getting error like this:
run:
java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:673)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:715)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:385)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:30)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:564)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at mydao.AdminDAO.connectionMethod(AdminDAO.java:33)
at mydao.AdminDAO.loginCheck(AdminDAO.java:43)
at mydao.AdminDAO.main(AdminDAO.java:74)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:445)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:464)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:594)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:229)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1360)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:486)
... 9 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:162)
at oracle.net.nt.ConnOption.connect(ConnOption.java:133)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:411)
... 14 more
Exception in thread "main" java.lang.NullPointerException
at mydao.AdminDAO.loginCheck(AdminDAO.java:61)
at mydao.AdminDAO.main(AdminDAO.java:74)
Java Result: 1
Can anyone help me getting out of this problem? I'm confused how to recover from this error.
Please try to start the TNS-Listener service in services.msc.
It seems that the server is not listening on the specified port or hostname.
Check if your service is running and if so check the port on which it is listening. If your oracle service is listening in different port update the same in your code and check.
This is my code to connect to SqlServer from Android Application
private Connection CONN(String _DB, String _server)
{
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
String connectionUrl = "jdbc:sqlserver://AhmedPc:1433; Instance=SQL2008;" +
"databaseName=admin1;integratedSecurity=true;";
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
try
{
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
con = DriverManager.getConnection(connectionUrl);
String SQL = "SELECT TOP 10 * FROM Person.Contact";
stmt = con.createStatement();
rs = stmt.executeQuery(SQL);
while (rs.next())
{
System.out.println(rs.getString(4) + " " + rs.getString(6));
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if (rs != null) try { rs.close(); } catch(Exception e) {}
if (stmt != null) try { stmt.close(); } catch(Exception e) {}
if (con != null) try { con.close(); } catch(Exception e) {}
}
return con;
}
I get this Error
When I use the Ip address 42.xx.xx.xx i get this::::
com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host has failed. java.net.ConnectException: failed to connect to / (port 1433): connect failed: ETIMEDOUT (Connection timed out)
When i use the 127.0.0.1 i get this:::::
com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host has failed. java.net.ConnectException: failed to connect to / (port 1433): connect failed: ECONNREFUSED (Connection refused)
I'm trying to connect to mysql database from my android application.
I'm getting Communications link failure error.Below is the code snippet:
public class MySqlConnector {
private Connection con = null;
private String s = "";
private String username = "root";
private String password = "password01";
private String connectionString;
public String ConnectToDb() {
connectionString ="jdbc:mysql://192.168.1.104:3306/mydatabase";
//connectionString="jdbc:mysql://10.0.0.0:3306/mydatabase";
// connectionString="jdbc:mysql://127.0.0.1:3306/mydatabase";
//connectionString = "jdbc:mysql://MainSrv04:3306/mydatabase";
// connectionString="jdbc:mysql://localhost:3306/mydatabase";
// connectionString =
// "jdbc:mysql://localhost:3306/mydatabase?user=root&password=password01&useUnicode=true&characterEncoding=UTF-8";
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (Exception ex) {
ex.printStackTrace();
}
try {
con = DriverManager.getConnection(connectionString, username,
password);
Statement st = con.createStatement();
String sql = "SELECT First_Name FROM mydatabase.custinfo where CardNumber=5325784707";
ResultSet rs = st.executeQuery(sql);
s = rs.getString("First_Name");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (con != null) {
try {
con.close();
Log.i("MySqlConnector", "Database connection terminated");
} catch (Exception e) { /* ignore close errors */
}
}
}
if (s == "") {
s = "No Result";
}
Log.i("MySqlConnector : s=", s);
return s;
}
}
I tried all possible combinations as showed in comments and getting following error in caused by field in logcat:
while using localhost --> Caused by: java.net.ConnectException: localhost/127.0.0.1:3306 - Connection refused
while using 127.0.0.1 --> Caused by: java.net.ConnectException: /127.0.0.1:3306 - Connection refused
while using 10.0.0.0 --> Caused by: java.net.SocketException: The operation timed out
while using 192.168.1.104 --> Caused by: java.net.SocketException: The operation timed out
while using MainSrv04 --> Caused by: java.net.UnknownHostException: MainSrv04
I also pinged mysql port through telnet and it's working.
Also, I have taken care of privileges.
But still I'm getting Communications link failure error.
Any help appreciated.
Is android application is on same ntework? If not
jdbc:mysql://192.168.1.104:3306
and
jdbc:mysql://10.0.0.0:3306
will not work.
Give the proper network address of mysql.
I use latest version of adt and mysql-connector-java-5.1.17-bin.jar, this works for me :
Add the below code into your file after the line setContentView(R.layout.activity_main);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
and use import android.os.StrictMode;
If you use new api, add #SuppressLint("NewApi");
Trying to create a JDBC based app that connects to a database allowing a user to edit a website.
Each time I test the app from eclipse I get a connection timed out error and have no idea why.
Sorry if it's a n00by question I'm new to JDBC. Any help or suggestions will be greatly appreciated.
Below is my code:
try
{
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection(
"jdbc:mysql://nkuwebdata.db.8750359.hostedresource.com",
username,
password);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("Select * FROM tbl_adminLogin");
while(rs.next())
{
String s = rs.getString("name");
System.out.println(s);
break;
}
} catch (SQLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Below is the Error Message that is printing out in my console:
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.ConnectException
MESSAGE: Connection timed out: connect
STACKTRACE:
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: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 uk.co.majorwebdesigns.ContentManager.connectToAndQueryDatabase(ContentManager.java:100)
at uk.co.majorwebdesigns.ContentManager.createMenuBar(ContentManager.java:92)
at uk.co.majorwebdesigns.ContentManager.launch(ContentManager.java:61)
at uk.co.majorwebdesigns.ContentManager.main(ContentManager.java:133)
** END NESTED EXCEPTION **
Last packet sent to the server was 2 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 uk.co.majorwebdesigns.ContentManager.connectToAndQueryDatabase(ContentManager.java:100)
at uk.co.majorwebdesigns.ContentManager.createMenuBar(ContentManager.java:92)
at uk.co.majorwebdesigns.ContentManager.launch(ContentManager.java:61)
at uk.co.majorwebdesigns.ContentManager.main(ContentManager.java:133)
Connection timeout generally occurs when the database server is not running.
dbname is missing in your code i guess. Just check this link
Class.forName("com.mysql.jdbc.Driver");
Connection conn = null;
conn = DriverManager.getConnection("jdbc:mysql://hostname:port/dbname","username", "password");
conn.close();
Several things: database not locally via localhost:3306 but over the net must pass through the firewall.
A port might be in order, for MySQL the default is 3306, as in localhost:3306.
Both these things might mean no connection, and would explain your error.
Things should be closed; otherwise one might run out of connections and such.
This can best be done with the try-with-resources construct.
And then one should almost use PreparedStatements to escape backslashes and quotes, and prevent SQL injection.
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
try (Connection con = DriverManager.getConnection(
"jdbc:mysql://nkuwebdata.db.8750359.hostedresource.com",
username,
password)) {
String sql = "SELECT * FROM tbl_adminLogin";
try (PreparedStatement stmt = con.prepareStatement(sql)) {
try (ResultSet rs = stmt.executeQuery()) {
if (rs.next()) {
String s = rs.getString("name");
System.out.println(s);
}
}
}
}
}
Check your connections credentials then also check server you are connecting is up and running.