Develop Reference

Java Download massive file giving Connection Shutdown/Reset on internet url after sometime

I am building a swing application to download multiple files over the internet and save to a windows fileshare. I have used SwingWroker which internally uses the ExecutorService which internally queues them and downloads 10 at a time, but for some reason after downloading say 2 - 3 MB of file it stops and moves to next downloading file, They are downloaded in a batch of 10 as SwingWorker has fixed it in number of Threads for the Executor Service.
I have to write these files in a windows file share and I am using nio.FileChannels to do that. There are files ranging from 50-60 each weighing around 300MB - 500MB. The file links are located on a webpage to where I get to by login in using credentials on a login page(with a post request) over the internet before that I specify CookieHandler.setDefault(new CookieManager()) at the beginning and so it behaves like a browser to me.
Another observation is when I download them locally (not to a windows server share) they do work fine.
This is the code I am using
import java.io.File;
import java.io.FileOutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import javax.swing.SwingWorker;
public class DownloadProcess extends SwingWorker<Boolean, String> {
private String urlPath, filePath;
public DownloadProcess(String urlPath, String filePath){
this.urlPath = urlPath;
this.filePath = filePath;
}
#Override
protected Boolean doInBackground() {
boolean taskState = true;
URLConnection httpConn = null;
ReadableByteChannel readableByteChannel = null;
FileOutputStream fileOutputStream = null;
FileChannel fileOutputChannel = null;
try{
//String filePath = "\\\\fileshare.server\\xyz.txt";
//String urlPath = "http://example.com/anyBigFile.1GB.docx";
File localFile = new File(filePath);//File share
boolean itsThere = localFile!=null && localFile.exists();
long done = itsThere ? localFile.length() : 0;
URL url = new URL(urlPath);
httpConn = url.openConnection();
httpConn.setRequestProperty("Connection", "keep-alive");
if(itsThere) {
httpConn.setRequestProperty("Range","bytes="+done+"-");
}
readableByteChannel = Channels.newChannel(httpConn.getInputStream());
fileOutputStream = itsThere ? new FileOutputStream(filePath) : new FileOutputStream(filePath,true);
fileOutputChannel = fileOutputStream.getChannel();
for (long position = done, size = httpConn.getContentLength(); position < size && !isCancelled(); ) {
position += fileOutputChannel.transferFrom(readableByteChannel, position, 1 << 16);
}
//done
}catch(Exception e){
taskState = false;
e.printStackTrace();
}finally{
//close streams conns etc
}
return taskState;
}
}
This is the error stack trace that I get after 5 - 10 mins of download
/*
javax.net.ssl.SSLException: Connection has been shutdown: javax.net.ssl.SSLException: java.net.SocketException: Connection reset
at sun.security.ssl.SSLSocketImpl.checkEOF(Unknown Source)
at sun.security.ssl.AppInputStream.read(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at sun.net.www.MeteredStream.read(Unknown Source)
at java.io.FilterInputStream.read(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(Unknown Source)
at java.nio.channels.Channels$ReadableByteChannelImpl.read(Unknown Source)
at com.objects.DownloadByteChannel.read(DownloadByteChannel.java:117)
at sun.nio.ch.FileChannelImpl.transferFromArbitraryChannel(Unknown Source)
at sun.nio.ch.FileChannelImpl.transferFrom(Unknown Source)
at com.core.DownloadTask.doInBackground(DownloadTask.java:154)
at com.core.DownloadTask.doInBackground(DownloadTask.java:59)
at com.util.ZSwingWorker$1.call(ZSwingWorker.java:286)
at java.util.concurrent.FutureTask.run(Unknown Source)
at com.util.ZSwingWorker.run(ZSwingWorker.java:325)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.net.ssl.SSLException: java.net.SocketException: Connection reset
at sun.security.ssl.Alerts.getSSLException(Unknown Source)
at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
at sun.security.ssl.SSLSocketImpl.handleException(Unknown Source)
at sun.security.ssl.SSLSocketImpl.handleException(Unknown Source)
... 18 more
Caused by: java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at sun.security.ssl.InputRecord.readFully(Unknown Source)
at sun.security.ssl.InputRecord.read(Unknown Source)
at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
at sun.security.ssl.SSLSocketImpl.readDataRecord(Unknown Source)
... 18 more
*/
Usage:
public static void main(String[] args){
int counter = 1;
for(String url: urls){
new DownloadProcess(url,"\\\\fileshare.server\\xyz"+(counter++)+".txt").execute();
}
}

You are going to have to change your connection timeout serverside. I picked up a few links along the way if they are of any importance:
Modify Session Security settings
Lengthening salesforce session timeout
Hope this helps, good luck and let me know :)

Connection Reset means the remote side is closing the connection with a TCP RST (reset) packet. You need to find out what the remote side isn't liking and fix it.
If the remote side is Apache maybe you are running into the KeepAliveTimeout value. By default that is 5 seconds. It really sounds like you are running into some sort of configured limit on the remote side. When that happens the server is kicking you off with a reset.

java.net.UnknownHostException when attempting to connect to database

I am attempting to connect to an Oracle database through Java with the Oracle JDBC driver with the following code (obscuring the host, service, user, and password):
import java.sql.*;
public class Main {
public Main () {
try {
String host = "HOST_NAME";
String port = "1521";
String service = "SERVICE_NAME";
String user = "SCHEMA_USER";
String password = "SCHEMA_PASSWORD";
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection connection = DriverManager.getConnection("jdbc:oracle:thin:#(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=" +
host +
")(PORT=" +
port +
")))(CONNECT_DATA=(SERVICE_NAME=" +
service +
")))",
user,
password);
connection.close ();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main (String args) {
new Main ();
}
}
However, I receive the following error:
java.sql.SQLException: IO Error: The Network Adapter could not establish the connection
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:458)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:546)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:236)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:521)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.acxiom.axle.reporting.database.DatabaseConnection.connect(DatabaseConnection.java:23)
at com.acxiom.axle.reporting.Reporting.establishDatabaseConnection(Reporting.java:53)
at com.acxiom.axle.reporting.Reporting.beginReporting(Reporting.java:20)
at com.acxiom.axle.reporting.Entry.<init>(Entry.java:28)
at com.acxiom.axle.reporting.Entry.main(Entry.java:118)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:392)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:434)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:687)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:247)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1102)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:320)
... 11 more
Caused by: java.net.UnknownHostException: null
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(Unknown Source)
at java.net.InetAddress.getAddressesFromNameService(Unknown Source)
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:117)
at oracle.net.nt.ConnOption.connect(ConnOption.java:133)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:370)
... 16 more
The strange thing is, I can connect to the database from PL/SQL Developer, I can ping the remote host, and I can telnet to the remote host on port 1521.
Why would only Java appear to give an UnknownHostException, but I can connect and ping the host with other applications?
EDIT: I removed "hr/hr" from the connection string above. I have tried the connection as-is with it removed and still receive the same error. I've also tried changing the connection string to match the version morgano listed in his answer, with the same result. Finally, I tried to change the port number to a port I know it's not listening on, and it still receives the same error.

The connection string is of the correct format. The problem is that the host isn't set. It's null, or perhaps the string "null". There's simply no other way to generate the error message java.net.UnknownHostException: null
In your sample code, you write String host = "HOST_NAME";. This makes it look like in your real code you are assigning a constant string to the variable host. However, I'm going to stick my neck out and say that in your real code you are not doing this. You are looking up the host name from somewhere, this lookup fails for some reason, you don't check this, and hence you pass a null value into the connection string.

Your JDBC url is wrong, according to the documentation it should be something like:
jdbc:oracle:driver_type:[username/password]#//host_name:port_number/service_name
In your case your code would be something like:
import java.sql.*;
public class Main {
public Main () {
try {
String host = "HOST_NAME";
String port = "1521";
String service = "SERVICE_NAME";
String user = "SCHEMA_USER";
String password = "SCHEMA_PASSWORD";
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection connection = DriverManager.getConnection(
"jdbc:oracle:thin:#//" + host
+ ":" + port + "/" + service, user, password);
connection.close ();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main (String args) {
new Main ();
}
}

Error when sending email in Java

I have a problem with sending emails in Java. I am using the JavaMail api to send emails. I have a program which downloads an email attachment using pop3, reads the content, does some manipulation and then sends the result in an email using smtp.
The program works fine until the last step where it sends the email and I get the following exception.
javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
nested exception is:
java.net.ConnectException: Connection refused: connect
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1961)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:654)
at javax.mail.Service.connect(Service.java:295)
at javax.mail.Service.connect(Service.java:176)
at javax.mail.Service.connect(Service.java:125)
at javax.mail.Transport.send0(Transport.java:194)
at javax.mail.Transport.send(Transport.java:124)
at com.adidas.monitoring.SendMail.sendMail(SendMail.java:46)
at com.adidas.monitoring.MainClass.main(MainClass.java:115)
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 java.net.Socket.connect(Unknown Source)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:321)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:237)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1927)
I am using the following code to send the email
public void sendMail(String strMailContent)
{
MimeMessage emailMessage;
Properties emailProperties = new Properties();
try {
emailProperties.load(new FileInputStream("Email.ini"));
} catch (IOException e){
DataLogger.logger.error(e.getMessage());
}
/*Get the properties from the email configuration file*/
String From = emailProperties.getProperty("Email.From");
String ToAdd = emailProperties.getProperty("Email.To");
String CC = emailProperties.getProperty("Email.CC");
String Subject = emailProperties.getProperty("Email.Subject");
String Host = emailProperties.getProperty("Email.Gateway");
emailProperties.setProperty("mail.smtp.host", Host);
Session emailSendSession = Session.getDefaultInstance(emailProperties);
try{
emailMessage = new MimeMessage(emailSendSession);
emailMessage.setFrom(new InternetAddress(From));
emailMessage.addRecipients(javax.mail.Message.RecipientType.TO,ToAdd);
emailMessage.addRecipients(javax.mail.Message.RecipientType.CC,CC);
emailMessage.setSubject(Subject);
emailMessage.setText(strMailContent);
Transport.send(emailMessage);
}
catch (Exception mailEx)
{
mailEx.printStackTrace();
}
}
The above code works fine when I use it with other programs. But when I am using it along with the pop3 code in this case, I have this error. Strange thing is the host is shown as localhost even though I set the property "mail.smtp.host".
Any help on this topic is really appreciated.

Connect to mySQL using eclipse

I am trying to run a JAVA program which inserts values into mySQL database. When I run the program, it says Connection refused: connect I have included mySQL jars also. What is the problem? Can anyone help me out
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class DataLogs {
public static void main(String[] args) throws SQLException,ClassNotFoundException {
Connection connection = null;
try {
//int i=0;
String strDate="", strTime="";
// Register MySQL JDBC driver to be known by
// the DriverManager object.
Class.forName("com.mysql.jdbc.Driver");
// Get a connection to database. We prepare the
// connection information here such as database
// url, user and password.
String url = "jdbc:mysql://localhost:8080/sampledatabase";
String user = "root";
String password = "root";
connection = DriverManager.getConnection(url, user, password);
// Create a statement object instance from the
// connection
Statement stmt = connection.createStatement();
// We are going to execute an insert statement.
// First you have to create a table that has an
// ID, NAME and ADDRESS field. For ID you can use
// an auto number, while NAME and ADDRESS are
// VARCHAR fields.
for(int i=1;i<=100;i++){
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String formattedDate = sdf.format(date);
strDate=getFormatedDate();
strTime=getTime();
String mm=strDate.substring(3, 5);
String yy=strDate.substring(8, 10);
String hh=strTime.substring(0, 2);
String mi=strTime.substring(3, 5);
String ss=strTime.substring(6, 8);
String dd=strDate.substring(0, 2);
String date1 = ""+yy+"-"+mm+"-"+dd+" "+hh+":"+mi+":"+ss;
String sql= "INSERT INTO `site_values_"+i+"` VALUES("+i+",5316,0,0,130,89,904,171,1006,96,4000,"+ss+","+mi+","+hh+","+dd+","+mm+","+yy+",84753,0,0,0,0,0,0,0,0,0,'Short Circuit Shutdown','Shutdown',1,'"+date1+"')";
// Call an execute method in the statement object
// and passed the sql or query string to it.
stmt.execute(sql);
}
// After this statement is executed you'll have a
// record in your users table.
} catch (ClassNotFoundException e) {
System.err.println("Could not load database driver!"+e);
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.close();
}
}
}
public static String getFormatedDate() {
String strDate="";
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdfdate = new SimpleDateFormat("dd/MM/yyyy");
strDate= sdfdate.format(cal.getTime());
return strDate;
}//getFormatedDate
public static String getTime() {
DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
java.util.Date date = new java.util.Date();
String datetime = dateFormat.format(date);
return datetime;
} //getTime
}
This is what I see in the console
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:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
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:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at solarnmsstandard.DataLogs.main(DataLogs.java:27)
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:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 15 more

Check if your connection parameters are correct (username, password) and especially the port where the MySql server is running.

check whether your mysql server is running or not, if it is not running then you will get this exception
java.net.ConnectException: Connection refused: connect
to run server
go to <mysql installation path>/bin/ and run mysqld.. to start the mysql server.
even after if you get the same error, provide the full stack trace.

check your port 8080 is free or not
if you are use linux run the follwing command and restart your server.
sudo kill sudo lsof -t -i:8080
sudo kill sudo lsof -t -i:8005
sudo kill sudo lsof -t -i:8009

I would be very suspicious of port 8080 being used as the port for MySQL; it really should be port 3306. So that would have to be checked properly as 8080 is usually the port number for an Application Server instance (such as GlassFish or Tomcat).

Fail to connect to james server localhost

I'm trying to connect to James server localhost, but I'm getting an exception
javax.mail.MessagingException: Could not connect to SMTP host: localhost, port:25;
nested exception is:
java.net.SocketException: Network is unreachable: connect
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1545)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:453)
at javax.mail.Service.connect(Service.java:313)
at javax.mail.Service.connect(Service.java:172)
at javax.mail.Service.connect(Service.java:121)
at javax.mail.Transport.send0(Transport.java:190)
at javax.mail.Transport.send(Transport.java:120)
at mail.main(mail.java:78)
Caused by: java.net.SocketException: Network is unreachable: 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 com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:267)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:227)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1511)
... 7 more
The directory structure of my James Server is:
C:\apache-james-2.3.2
|
|
|
|------C:\apache-james-2.3.2\james-2.3.2
|
|------C:\apache-james-2.3.2\javamail-1.4.2
|
|------C:\apache-james-2.3.2\jaf-1.0.2
Here's the code, which is throwing an exception:
I've not changed anything in the config file of james-2.3.2 subdirectory, then why I'm
getting that exception?
Here's the code, which is throwing an exception:
// imports omitted
public class mail {
public static void main(String[] args) {
String to = "blue#localhost";
String from = "red#localhost";
String subject = "Hello";
String body = "What's up";
if ((from != null) && (to != null) && (subject != null) && (body != null)) {
try { // we have mail to send
Properties props = new Properties();
props.put("mail.host", "localhost");
props.put("mail.smtp.auth", "true");
props.put("mail.debug", "true");
Session session = Session.getInstance(props, new javax.mail.Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("red", "red");
}
});
Message message = new MimeMessage(session);
message.setFrom(new InternetAddress(from));
Address[] add = { new InternetAddress(to) };
message.setRecipients(Message.RecipientType.TO, add);
message.setSubject(subject);
message.setContent(body, "text/plain");
message.setText(body);
Transport.send(message);
System.out.println(" Your message to " + to + " was successfully sent.");
} catch (Throwable t) {
t.printStackTrace();
}
}
}
}

The exception is saying that localhost is unreachable. I expect that your machine does not have its loopback network address (localhost / 127.0.0.1) correctly configured.
EDIT: I assume that you are running the client and server on the same machine. If not, you cannot use localhost / 127.0.0.1.

I always try to telnet to port 25 on the mailhost, to check if the server can be reached. Try to connect to 127.0.0.1 to check if James is accepting incoming connections. I presume you have checked the logs of James for errors?

Try using the IP address 127.0.0.1 instead of the hostname 'localhost' - maybe DNS lookup on your machine is not set up properly, so that it doesn't know what the name 'localhost' means.
Open the file C:\Windows\System32\drivers\etc\hosts, and make sure it contains a line like this:
127.0.0.1 localhost
Also, try switching off your firewall or anti-virus software.

try to start apache james as root user in linux or start as
Administrator on windows. and check the server is successfully
started or not on james-server.log file in logs folder
add the host name on your hosts file
127.0.0.1 localhost
file placed
on linux /etc/hosts
on windows C:\Windows\System32\drivers\etc\hosts
and restart your server.