Develop Reference

Connect to Athena using JDBC in a maven project

I'm trying to connect to the Amazon Athena, using jdbc in a maven project, but an exception is being raised. I think that the class is not being found. In Athena's guide it says:
Set the JDBC property, aws_credentials_provider_class, equal to the class name, and include itin your classpath. (1)
Since I'm using eclipse, I thought that the class would be already in the classpath, but apparently not. I tested the code in a simple java project (not maven) and it worked.
AmazonCredentialsProvider.java:
package athena;
import com.amazonaws.auth.AWSCredentials;
public class AmazonCredentials implements AWSCredentials {
#Override public String getAWSAccessKeyId() { return "..."; }
#Override public String getAWSSecretKey() { return "..."; }
}
AmazonCredentialsProvider.java:
package athena;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSCredentialsProvider;
public class AmazonCredentialsProvider implements AWSCredentialsProvider {
#Override public AWSCredentials getCredentials() { return new AmazonCredentials(); }
#Override public void refresh() {}
}
The code snippet of the connection :
Class.forName("com.amazonaws.athena.jdbc.AthenaDriver");
Properties properties = new Properties();
properties.setProperty("user", user);
properties.setProperty("password", password);
properties.setProperty("aws_credentials_provider_class", "athena.AmazonCredentialsProvider");
Connection connection = DriverManager.getConnection("jdbc:awsathena://athena." + region + ".amazonaws.com:443", properties);
The exception:
java.sql.SQLException: Failed to load AWS credentials provider class:
athena.AmazonCredentialsProvider at
com.amazonaws.athena.jdbc.AthenaDriverPropertiesFactory.lambda$parseProperties$2(AthenaDriverPropertiesFactory.java:52)
at
com.amazonaws.athena.jdbc.AthenaDriverPropertiesFactory.setClientConfigProperty(AthenaDriverPropertiesFactory.java:159)
at
com.amazonaws.athena.jdbc.AthenaDriverPropertiesFactory.parseProperties(AthenaDriverPropertiesFactory.java:40)
at
com.amazonaws.athena.jdbc.AthenaDriver.connect(AthenaDriver.java:110)
at java.sql.DriverManager.getConnection(Unknown Source) at
java.sql.DriverManager.getConnection(Unknown Source) at
athena.Athena.(Athena.java:94) at
services.GraphService.verify(GraphService.java:194) at
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at
java.lang.reflect.Method.invoke(Unknown Source) at
org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:76)
at
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:148)
at
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:191)
at
org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$VoidOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:183)
at
org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:103)
at
org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:493)
at
org.glassfish.jersey.server.model.ResourceMethodInvoker.lambda$apply$0(ResourceMethodInvoker.java:405)
at
org.glassfish.jersey.server.ServerRuntime$AsyncResponder$2$1.run(ServerRuntime.java:843)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:272) at
org.glassfish.jersey.internal.Errors$1.call(Errors.java:268) at
org.glassfish.jersey.internal.Errors.process(Errors.java:316) at
org.glassfish.jersey.internal.Errors.process(Errors.java:298) at
org.glassfish.jersey.internal.Errors.process(Errors.java:268) at
org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:289)
at
org.glassfish.jersey.server.ServerRuntime$AsyncResponder$2.run(ServerRuntime.java:838)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown
Source) at java.util.concurrent.FutureTask.run(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at
java.lang.Thread.run(Unknown Source) Caused by:
java.lang.ClassNotFoundException: athena.AmazonCredentialsProvider at
java.net.URLClassLoader.findClass(Unknown Source) at
java.lang.ClassLoader.loadClass(Unknown Source) at
java.lang.ClassLoader.loadClass(Unknown Source) at
java.lang.Class.forName0(Native Method) at
java.lang.Class.forName(Unknown Source) at
com.amazonaws.athena.jdbc.AthenaDriverPropertiesFactory.lambda$parseProperties$2(AthenaDriverPropertiesFactory.java:44)
... 31 more
Does anyone know how to solve it?

Are you using the latest version of the JDBC driver?
If yes, try to follow these instructions:
https://docs.aws.amazon.com/redshift/latest/mgmt/configure-jdbc-connection-with-maven.html

java mysql db connection

i'm new in java.
I'm trying to connect mysql DB in java
i've got this
mysql.java file:
package program;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class mysql {
private static final String DATABASE_DRIVER = "com.mysql.jdbc.Driver";
private static final String DATABASE_URL = "jdbc:mysql://mysql.cba.pl:3306/dbname";
private static final String USERNAME = "login";
private static final String PASSWORD = "pass";
private static final String MAX_POOL = "250";
private Connection connection;
private Properties properties;
private Properties getProperties() {
if (properties == null) {
properties = new Properties();
properties.setProperty("user", USERNAME);
properties.setProperty("password", PASSWORD);
properties.setProperty("MaxPooledStatements", MAX_POOL);
}
return properties;
}
public Connection connect() {
if (connection == null) {
try {
Class.forName(DATABASE_DRIVER);
connection = DriverManager.getConnection(DATABASE_URL, getProperties());
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
return connection;
}
public void disconnect() {
if (connection != null) {
try {
connection.close();
connection = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
main java file:
package program;
public class main {
public static void main(String[] args){
mysql db = new mysql();
db.connect();
}
}
and i'm getting following errors
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
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 komunikator.mysql.connect(mysql.java:31)
at komunikator.main.main(main.java:7)
I downloaded ojdbc6-11.2.0.2.0.jar and put in my project folder, after that i add library from jar file.
What i'm doing wrong ?
I'm really new in java so i hope somebody can help me as well :)
I'm using Eclipse Standard/SDK
Version: Kepler Release
Build id: 20130614-0229

ou need to use com.mysql.jdbc_5.1.5 driver for mysql connection and paste jar file in to WEB-INF>Lib folder and use the path of jar file into property>buildpath and use external jar.

it will be a normal desktop application
ok, i changed it on com.mysql.jdbc_5.1.5 driver, i paste this in project path with others .java files and added like u said in properties.
Now i'm getting this:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
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:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2104)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:729)
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:406)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:283)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at program.mysql.connect(mysql.java:32)
at program.main.main(main.java:7)
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 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:276)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2027)
... 13 more
Is mysql.java file correct ?
Edit:
i tried change this
private static final String DATABASE_DRIVER = "com.mysql.jdbc.Driver";
on
"com.mysql.jdbc_5.1.5.Driver"
and i am gettin some less errors
java.lang.ClassNotFoundException: com.mysql.jdbc_5.1.5.Driver
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 program.mysql.connect(mysql.java:31)
at program.main.main(main.java:7)

Ok, almost i've got this. One thing more.
When im trying connect to on-line DB i got this:
SQLException: 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.
SQLState: 08S01
VendorError: 0
on localhost DB (xamp) it's working fine
what is going on ?

Unable to connect to sql server using java 8

I'm trying to connect to my sql server 21014 using java 8. But i'm getting error.
import java.sql.*;
import java.io.*;
import java.net.*;
import java.util.Scanner;
public class DBConnec
{
public static void main(String a[])
{
try
{
String url = "jdbc:jtds:sqlserver//localhost:1433/dictionary";
Class.forName("net.sourceforge.jtds.jdbc.Driver");
Connection conn = DriverManager.getConnection(url);
System.out.println("connection created");
Statement st=conn.createStatement();
String sql="select * from data where word LIKE 'hi'";
ResultSet rs=st.executeQuery(sql);
if (rs.next())
{
System.out.println(rs.getString(0));
}
if(st!=null)
st.close();
if(conn!=null)
conn.close();
}
catch(SQLException sqle)
{
sqle.printStackTrace();
}
catch(ClassNotFoundException e)
{
e.printStackTrace();
}
}
}
Exception i'm getting is:
java.sql.SQLException: The syntax of the connection URL 'jdbc:jtds:sqlserver//localhost:1433/dictionary' is invalid.
at net.sourceforge.jtds.jdbc.Driver.setupConnectProperties(Driver.java:241)
at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:181)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at DBConnec.main(DBConnec.java:15)
I'm running my code using this command:
java -cp .;"C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\jtds-1.3.0.jar" DBConnec
I've also tried url without writing "sqlserver". But it gives same exception.
Please help.. Thank you..
I've corrected my syntax but now i'm getting exception like this:
java.sql.SQLException: Network error IOException: Connection refused: connect
at net.sourceforge.jtds.jdbc.JtdsConnection.(JtdsConnection.java:434)
at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:183)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at DBConnec.main(DBConnec.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 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)

Try this:
String url = "jdbc:jtds:sqlserver://localhost:1433/dictionary";
You missed the colon after sqlserver.
You should not be adding JDBC driver JARs to the jre/lib/ext directory. Learn how to use CLASSPATH properly.

The url format for JTDS is:
jdbc:jtds:<server_type>://<server>[:<port>][/<database>][;<property>=<value>[;...]]
So your url should be like:
String url = "jdbc:jtds:sqlserver://localhost:1433/dictionary";
^^^____missing colon

Getting resource error accessing Redis Q multiple times

This is my code used to access the value from redis Q.
Jedis jedis = null;
try
{
int maxActive = 1000;
int maxIdle = 5;
int minIdle = 1;
long maxWait = 5000;
JedisPoolConfig config = new JedisPoolConfig ();
config.setMaxActive (maxActive);
config.setMaxIdle (maxIdle);
config.setMinIdle(minIdle);
config.setMaxWait (maxWait);
config.setTestOnBorrow (false);
pool = new JedisPool (config, RedisServerURL) ;
jedis = pool.getResource();
jedis.getClient().setTimeoutInfinite();
redisQMesssage = jedis.rpop(RedisQ);
//my code
}
catch (Exception e)
{
e.printStackTrace();
}
finally{
pool.returnResource(jedis);
pool.destroy();
}
I have the above code in 3 worker threads. i'm calling the 3 worker thread for 40 times(totally).
Rarely 1/5 times i'm getting the error "Could not get a resource from the pool(SocketTimeoutException:)"
Stack trace is
redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
at redis.clients.util.Pool.getResource(Pool.java:22)
at Workers.Worker1.met1(Worker1.java:124)
at Workers.Worker1.work(Worker1.java:108)
at org.gearman.impl.worker.WorkerConnectionController$3.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: connect timed out
at redis.clients.jedis.Connection.connect(Connection.java:124)
at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:54)
at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1657)
at redis.clients.jedis.JedisPool$JedisFactory.makeObject(JedisPool.java:63)
at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1188)
at redis.clients.util.Pool.getResource(Pool.java:20)
... 6 more
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 redis.clients.jedis.Connection.connect(Connection.java:119)
... 11 more
Please help me out.

Getting [google-api-translate-java] Error retrieving translation. error when using google transaltor in java

When using google api to translate the text I am getting the following error.
com.google.api.GoogleAPIException: java.lang.Exception: [google-api-translate-java] Error retrieving translation.
at com.google.api.translate.TranslateV2.execute(TranslateV2.java:68)
at GoogleTranslator.main(GoogleTranslator.java:16)
Caused by: java.lang.Exception: [google-api-translate-java] Error retrieving translation.
at com.google.api.GoogleAPI.retrieveJSON(GoogleAPI.java:99)
at com.google.api.translate.TranslateV2.execute(TranslateV2.java:62)
... 1 more
Caused by: java.io.IOException: Server returned HTTP response code: 400 for URL: https://www.googleapis.com/language/translate/v2?key=AIzaSyAmtyPllqBCXu5rVikedZw8IErGCCfEdtw&q=How+are+you%3F&target=hi&source=en
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 sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at com.google.api.GoogleAPI.retrieveJSON(GoogleAPI.java:93)
... 2 more
Caused by: java.io.IOException: Server returned HTTP response code: 400 for URL: https://www.googleapis.com/language/translate/v2?key=AIzaSyAmtyPllqBCXu5rVikedZw8IErGCCfEdtw&q=How+are+you%3F&target=hi&source=en
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at com.google.api.GoogleAPI.retrieveJSON(GoogleAPI.java:89)
... 2 more
and my code is:
import com.google.api.GoogleAPI;
import com.google.api.translate.Language;
import com.google.api.translate.Translate;
public class GoogleTranslator {
/**
* #param args
* the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
try {
// Translate.setHttpReferrer(“en-fr”);
GoogleAPI.setHttpReferrer("http://www.google.com");
GoogleAPI.setKey("my key");
String translatedText = Translate.DEFAULT.execute("How are you?",
Language.ENGLISH, Language.HINDI);
System.out.println(translatedText);
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
Please need your help in resolving this.