I am using the following code to read some data from Android client. All is going fine. But now i am asked to make this server code non blocking. Is there any suggestions for this ? I was trying to use threads but dont know how ? I am beginner in Java :)
Thanks
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Calendar;
import java.util.Date;
import javax.imageio.ImageIO;
public class Server {
//Server Constructor
public Server()
{}
//Variables Initialization
private static ServerSocket server;
byte[] imagetemp;
private static Socket socket1;
private static boolean newImage;
private static Sdfdata data;
private static boolean cond;
public static int port;
private static int number = 0;
//Image Availability return method
public boolean imageAvailable()
{
return newImage;
}
public boolean clientchk()
{
return socket1.isClosed();
}
//Image Flag set by Vis group when image read.
public void setImageFlag(boolean set)
{
newImage = set;
}
// Send the data to the Vis Group
public Sdfdata getData()
{
return data;
}
//Starts the Server
public static boolean start(int port1)
{
try {
port=port1;
server = new ServerSocket(port1);
System.out.println("Waiting for Client to Connect");
//New thread here
socket1=server.accept();
} catch (IOException e) {
System.out.println("Cannot Connect");
e.printStackTrace();
return false;
}
return true;
}
//Stops the Server
public boolean stop()
{
try {
socket1.close();
}
catch (IOException e)
{
e.printStackTrace();
return false;
}
return true;
}
/**
* #param args
* #throws IOException
*/
public static void main(String[] args) throws IOException {
// Starts the server
start(4444);
// DataInput Stream for reading the data
DataInputStream in = null;
try {
in = new DataInputStream(socket1.getInputStream());
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
cond=true;
do {
try
{
//Read Image Data
int length = in.readInt();
//Create an ByteArray of length read from Client for Image transfer
Sdfdata data = new Sdfdata(length);
//for (int i=0; i<length; i++)
//{ data.image[i] = in.readbyte(); }
if (length > 0) {
in.readFully(data.image);
}
//Read Orientation
data.orientation[0] = in.readFloat(); //Orientation x
data.orientation[1] = in.readFloat(); //Orientation y
data.orientation[2] = in.readFloat(); //Orientation z
//Read GPS
data.longitude = in.readDouble();
data.latitude = in.readDouble();
data.altitude = in.readDouble();
//Display orientation and GPS data
System.out.println(data.orientation[0] + " " + data.orientation[1] + " " + data.orientation[2]);
System.out.println(data.longitude + " " + data.latitude + " " + data.altitude);
String fileName = "IMG_" + Integer.toString(++number) + ".JPG";
System.out.println("FileName: " + fileName);
FileOutputStream fos = new FileOutputStream(fileName);
fos.write(data.image);
fos.close();
/*InputStream ins = new ByteArrayInputStream(data.image);
BufferedImage image = ImageIO.read(ins);
ImageIO.write(image, "JPG", new File (fileName));
*/
//set image flag
newImage = true;
} catch (Exception e) {
//System.out.println("EOF Or ? " + e);
cond =false;
socket1.close();
server.close();
start(port);
}
}while (cond);
}
}
Your code starts a server, waits for a connection, reads some data from the first connected client, and then exits after writing this data to a file.
Being asked to make your server "non-blocking" could mean that you are being asked to change it to use asynchronous IO (probably unlikely), or it could mean that you're being asked to handle more than one client at a time - because currently you can only serve one client and then your program exits.
This question is hard to answer because your current code is very far away from where you need it to be and it seems like some reading up on networking, sockets, and Java programming in general would be a good way to start.
I'd recommend Netty for doing anything network-related in Java and their samples and documentation are good and easy to follow. Good luck!
Related
import javax.swing.*;
import java.io.Serializable;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
public class Server implements Serializable{
public static void main(String[] args) {
String test1= JOptionPane.showInputDialog(null,"Port(0-65535):","Port",JOptionPane.QUESTION_MESSAGE);
int portnumber = tryParse(test1);
if (portnumber !=0) {
try {
Registry reg = LocateRegistry.createRegistry(portnumber); //Creates and exports a Registry instance on the local host that accepts requests
RmiImplementation imp = new RmiImplementation("C://ServerStorage");
reg.bind("remoteObject", imp);
System.out.println("Server is ready.");
System.out.println(portnumber);
} catch (Exception e) {
System.out.println("Server failed: " + e);
}
}
}
private static Integer tryParse(String text) {
try {
return Integer.parseInt(text);
} catch (Exception e) {
return 0;
}
}
}
The above code helps me to set up my file server.
when the application is run, the dialog port number is requested.
If I type letters instead of numbers the program stops running, but I want it to continue and show me the dialog again.
Try with a do-while,
int portnumber = 0;
do {
String text= JOptionPane.showInputDialog(null,"Port(0-65535):","Port",JOptionPane.QUESTION_MESSAGE);
portnumber = tryParse(text);
}while(portnumber==0);
I am trying to create a TFTP client using java NIO. I am able to receive first 512 bytes of data from server, but not able to send acknowledgement to server for getting next block of packet. I am new to java NIO and networking. Not able to find solution for it. So can anyone help me on this to find fix for it? Thanks in advance
package app.sdc.business;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.Iterator;
import app.sdc.business.NetworkElementPool.NetworkElement;
public class TftpNioClient {
static byte OP_ERROR = 5, OP_DATAPACKET = 3, OP_ACK = 4, OP_RRQ = 1, OP_WRQ = 2;
static final String LOCALHOST = "localhost";
static InetSocketAddress server = new InetSocketAddress(LOCALHOST, 69);
// main method
public static void main(String[] args) throws IOException {
processDownload();
}
// Will start downloading of all files
public static void processDownload() throws IOException {
Selector sel = Selector.open();
for (NetworkElement ne : NetworkElementPool.getNetworkElements()) {
DatagramChannel channel = DatagramChannel.open();
channel.configureBlocking(false);
channel.connect(server);
channel.register(sel, SelectionKey.OP_READ | SelectionKey.OP_WRITE, ne);
}
int counter = 0;
while (true) {
int n = sel.select(3000);
if (n < 1) {
continue;
}
Iterator<SelectionKey> itr = sel.selectedKeys().iterator();
while (itr.hasNext()) {
SelectionKey key = itr.next();
itr.remove();
if (key.isWritable()) {
counter++;
System.out.println("channel Write...");
downloadUsingTFTPProtocol(key);
} else if (key.isReadable()) {
System.out.println("Channel Read");
}
}
if (counter >= NetworkElementPool.getNetworkElements().size()) {
break;
}
}
}
// method for downloading file
private static void downloadUsingTFTPProtocol(SelectionKey keyy) throws IOException {
ByteArrayOutputStream byteOutOS = new ByteArrayOutputStream();
Selector sel = keyy.selector();
NetworkElement ne = (NetworkElement) keyy.attachment();
String fileName = ne.getFilename();
DatagramChannel channel = DatagramChannel.open();
channel.configureBlocking(false);
channel.register(sel, SelectionKey.OP_READ | SelectionKey.OP_WRITE);
boolean reqSent = false;
ByteBuffer sendBuffer = null;
ByteBuffer receivedBuffer = ByteBuffer.allocate(516);
boolean stop = false;
byte[] dataByte = null;
boolean received = false;
outer: while (true) {
int n = sel.select();
if (n < 1) {
continue;
}
Iterator<SelectionKey> itr = sel.selectedKeys().iterator();
while (itr.hasNext()) {
SelectionKey key = itr.next();
itr.remove();
DatagramChannel dc = (DatagramChannel) key.channel();
if (!received && key.isReadable()) {
System.out.println("receive packet...");
receivedBuffer.clear();
dc.receive(receivedBuffer);
stop = receivedBuffer.position() < 512;
receivedBuffer.flip();
while (receivedBuffer.hasRemaining()) {
System.out.print(receivedBuffer.get());
}
System.out.println();
dataByte = receivedBuffer.array();
received = true;
}
if (key.isWritable()) {
if (!reqSent) {
System.out.println("Sending First Request....");
sendBuffer = createInitialReadRequest("SDCSource/" + fileName);
sendBuffer.flip();
dc.send(sendBuffer, server);
reqSent = true;
} else if (received) {
System.out.println("Send Acknowledgement");
byte[] opCode = new byte[] { dataByte[0], dataByte[1] };
if (opCode[1] == OP_ERROR) {
System.out.println("Error Occured...");
break outer;
} else if (opCode[1] == OP_DATAPACKET) {
byte[] blockNumber = { dataByte[2], dataByte[3] };
sendBuffer = getAcknowledgment(blockNumber, dc, server);
sendBuffer.flip();
dc.send(sendBuffer, server);
DataOutputStream dos = new DataOutputStream(byteOutOS);
dos.write(dataByte, 4, dataByte.length - 4);
}
}
received = false;
}
if (stop) {
break outer;
}
}
}
writeFile(byteOutOS, fileName);
}
// Creates request packet to send request at the beginning
private static ByteBuffer createInitialReadRequest(final String fileName) {
String mode = "octet";
int rrqByteLength = 2 + fileName.getBytes().length + 1 + mode.getBytes().length + 1;
byte[] rrqByteArray = new byte[rrqByteLength];
ByteBuffer reqBuf = ByteBuffer.allocate(rrqByteArray.length);
reqBuf.put((byte) 0).put((byte) OP_RRQ);
reqBuf.put(fileName.getBytes());
reqBuf.put((byte) 0);
reqBuf.put(mode.getBytes());
reqBuf.put((byte) 0);
return reqBuf;
}
// Creating acknowledgement code
private static ByteBuffer getAcknowledgment(byte[] blockNumber, DatagramChannel channel, InetSocketAddress server)
throws IOException {
byte[] acknowledge = { 0, OP_ACK, blockNumber[0], blockNumber[1] };
ByteBuffer buffer = ByteBuffer.allocate(acknowledge.length);
buffer.put(acknowledge);
return buffer;
}
// Create file after all packets have been received
private static void writeFile(ByteArrayOutputStream baoStream, String fileName) {
try {
OutputStream outputStream = new FileOutputStream("SDCTarget/" + fileName);
baoStream.writeTo(outputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
}
package app.sdc.business;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
public class NetworkElementPool {
private static List<NetworkElement> networkElements;
// create a list of network elements by reading files downloading. It is just a hard-coded way to create network elements
static {
networkElements = new ArrayList<NetworkElement>();
File sourceDir = new File("C:/OpenTFTPServer/SDCSource");
if (sourceDir.exists()) {
for (String filename : sourceDir.list()) {
networkElements.add(new NetworkElement("localhost", 8080, filename));
}
} else {
System.err.println("Network Elements couldn't found...");
}
}
public static List<NetworkElement> getNetworkElements() {
return networkElements;
}
// Represents a network element
public static class NetworkElement {
private String host;
private int port;
private String filename;
public String getHost() {
return host;
}
public int getPort() {
return port;
}
public String getFilename() {
return filename;
}
public NetworkElement() {
super();
}
public NetworkElement(String host, int port, String filename) {
super();
this.host = host;
this.port = port;
this.filename = filename;
}
#Override
public String toString() {
return "NetworkElement [host=" + host + ", port=" + port + ", filename=" + filename + "]";
}
}
}
Note: TftpClient class contain one foreach loop to start downloading file from more than one network element.
You're not sending the acknowledgements at the correct time, after a read: you're sending them every time around the loop. You don't need to wait for OP_WRITE to do a write. Just write whenever you need to. You shouldn't even register for OP_WRITE most of the time. See this answer for the correct technique. But in the case of TFTP it's dubious whether you need that at all. Or NIO either.
In your code, if the key.isReadable, then you can read the packet. Then immediately followed by that you can send the ACK back to TFTP server.
} else if (received) {
This block of code can go to the line immediately next to dc.receive(receivedBuffer);
You can refer this example java nio tftp client
I am trying to implement a persistent http server in java, being new in socket programming, I am unaware of the complications.
But run function of ThreadHandler class, it stucks forever and keep waiting, but at the same time if new request comes a new connection is being made instead of using the previous connection itself (while the initial connection keep waiting for request).
Please suggest the correction
here is my server code that calls ThreadHandler for threading.
Server code
package httpServer;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.*;
public class Server {
static int countofconnections = 0;
public static void main(String[] args) throws IOException {
int port = 14998;
ServerSocket socketServerSocket = new ServerSocket(port);
while(true) {
Socket socketClientSocket = socketServerSocket.accept();
countofconnections++;
//Runnable handler = new TinyHttpdSocketHandler(socket);
ThreadHandler threadHandler = new ThreadHandler(socketClientSocket);
Thread socketThread = new Thread(threadHandler, "Thread for " + socketClientSocket.toString());
System.out.println(" connection count is now : " + countofconnections+ " ");
socketThread.setDaemon(true);
socketThread.start();
}
}
}
ThreadHandler code:
package httpServer;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import java.net.SocketTimeoutException;
//import java.util.ArrayList;
public class ThreadHandler implements Runnable{
Socket socketClientSocket;
//ServerSocket socketServerSocket;
ThreadHandler(Socket socketClientSocket){
this.socketClientSocket = socketClientSocket;
//this.socketServerSocket = socketServerSocket;
}
#Override
public void run(){
boolean alive = false;
try {
int count = 0;
socketClientSocket.setSoTimeout(40000);
BufferedReader inputFromClient = new BufferedReader(new InputStreamReader(socketClientSocket.getInputStream()));
DataOutputStream outputToClient = new DataOutputStream(socketClientSocket.getOutputStream());
String messegeFromClient = inputFromClient.readLine();
System.out.println(messegeFromClient);
while(messegeFromClient!=null) {
String requestString = messegeFromClient;
System.out.println("entering while loop");
//String in = inputFromClient.readLine();
while(messegeFromClient!=null && !messegeFromClient.equals("")) {
//System.out.printlnln(in);
messegeFromClient = inputFromClient.readLine();
//System.out.println(messegeFromClient);
if(messegeFromClient.startsWith("Connection:")) {
String[] connectionTimeString = messegeFromClient.split(" ");
if(connectionTimeString[1].equals("keep-alive")) {
alive = true;
//System.out.println("keep alive found");
}
}
}
count++;
System.out.println(count);
//System.out.printlnln( messegeFromClient);
String[] tokensStrings = requestString.split(" ");
if(tokensStrings[0].equals("GET")) {
String requestedFilename = tokensStrings[1];
if(requestedFilename.startsWith("/")) {
requestedFilename = requestedFilename.substring(1);
if(requestedFilename.startsWith("~")) {
requestedFilename = "/home/suman/users/"+requestedFilename.substring(1);
}
else {
requestedFilename = "/home/suman/public_html/"+requestedFilename;
}
System.out.println(requestedFilename);
}
File filetosend = new File(requestedFilename);
int filesize = (int) filetosend.length();
FileInputStream fileStream = null;
boolean fileFound = true;
try {
fileStream = new FileInputStream(requestedFilename);
} catch (Exception e) {
fileFound = false;
}
if(fileFound) {
byte[] fileinByte =new byte[filesize];
fileStream.read(fileinByte);
outputToClient.writeBytes("HTTP/1.0 200 Document Follows\r\n");
outputToClient.writeBytes("Content-Length: "+filesize+"\r\n\r\n");
outputToClient.write(fileinByte, 0, filesize);
}
else {
outputToClient.writeBytes("HTTP/1.0 404 Document NOT FOUND\r\n\r\n");
outputToClient.writeBytes("404 document not found");
}
outputToClient.flush();
if(alive) {
socketClientSocket.setKeepAlive(true);
socketClientSocket.setSoTimeout(100000);
}
else {
socketClientSocket.close();
System.out.println("closing socket");
break;
}
//socketClientSocket.setSoTimeout(5000);
}
System.out.println("waiting");
messegeFromClient=inputFromClient.readLine();
while( messegeFromClient == null ) {
//this code should be skipped when a new request is made since message from from client will no longer be null in that case
messegeFromClient=inputFromClient.readLine();
}
if(messegeFromClient==null) {
System.out.println("messege is null... I don't think it would be ever executed.");
}
}
socketClientSocket.close();
System.out.println("closing socket 2");
} catch ( SocketTimeoutException e) {
try {
socketClientSocket.close();
System.out.println("socket closed");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
} catch (IOException ie) {
ie.printStackTrace();
}
}
}
I looked into at4j and 7-Zip-JBinding (their javadoc and documentation) but they doesn't seem to be able to read without extracting (and get an InputStream from archived file)
Is there any method I'm missing or haven't found ?
a solution other than extracting to a temporary folder to read it
I'm expecting an answer in how to do it in at4j or 7-Zip-JBinding
in other words I want to know how to utilize below mentioned function in at4j or 7-Zip-JBinding
I know java's built in one has getInputStream I'm currently using it this way
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
/**
* get input stream of current file
* #param path path inside zip
* #return InputStream
*/
public InputStream getInputStream(String path){
try {
ZipEntry entry = zipFile.getEntry(path);
if(entry!=null){
return zipFile.getInputStream(entry);
}
return new ByteArrayInputStream("Not Found".getBytes());
} catch (Exception ex) {
//handle exception
}
return null;
}
(^^ zipFile is a ZipFile object)
found the solution using 7-Zip-JBinding
just need to use ByteArrayInputStream ,this so far worked for a small file
pass a archive as argument to get all files inside printed
file ExtractItemsSimple.java
import java.io.IOException;
import java.io.RandomAccessFile;
import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.impl.RandomAccessFileInStream;
import net.sf.sevenzipjbinding.simple.ISimpleInArchive;
import net.sf.sevenzipjbinding.simple.ISimpleInArchiveItem;
public class ExtractItemsSimple {
public static void main(String[] args) {
RandomAccessFile randomAccessFile = null;
ISevenZipInArchive inArchive = null;
try {
randomAccessFile = new RandomAccessFile(args[0], "r");
inArchive = SevenZip.openInArchive(null, // autodetect archive type
new RandomAccessFileInStream(randomAccessFile));
ISimpleInArchive simpleInArchive = inArchive.getSimpleInterface();
for (ISimpleInArchiveItem item : simpleInArchive.getArchiveItems()) {
final int[] hash = new int[] { 0 };
if (!item.isFolder()) {
System.out.println(ArchieveInputStreamHandler.slurp(new ArchieveInputStreamHandler(item).getInputStream(),1000));
}
}
} catch (Exception e) {
System.err.println("Error occurs: " + e);
System.exit(1);
} finally {
if (inArchive != null) {
try {
inArchive.close();
} catch (SevenZipException e) {
System.err.println("Error closing archive: " + e);
}
}
if (randomAccessFile != null) {
try {
randomAccessFile.close();
} catch (IOException e) {
System.err.println("Error closing file: " + e);
}
}
}
}
}
file ArchieveInputStreamHandler.java
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import net.sf.sevenzipjbinding.ISequentialOutStream;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.simple.ISimpleInArchiveItem;
public class ArchieveInputStreamHandler {
private ISimpleInArchiveItem item;
private ByteArrayInputStream arrayInputStream;
public ArchieveInputStreamHandler(ISimpleInArchiveItem item) {
this.item = item;
}
public InputStream getInputStream() throws SevenZipException{
item.extractSlow(new ISequentialOutStream() {
#Override
public int write(byte[] data) throws SevenZipException {
arrayInputStream = new ByteArrayInputStream(data);
return data.length; // Return amount of consumed data
}
});
return arrayInputStream;
}
//got from http://stackoverflow.com/questions/309424/read-convert-an-inputstream-to-a-string
public static String slurp(final InputStream is, final int bufferSize){
final char[] buffer = new char[bufferSize];
final StringBuilder out = new StringBuilder();
try {
final Reader in = new InputStreamReader(is, "UTF-8");
try {
for (;;) {
int rsz = in.read(buffer, 0, buffer.length);
if (rsz < 0)
break;
out.append(buffer, 0, rsz);
}
}
finally {
in.close();
}
}
catch (UnsupportedEncodingException ex) {
/* ... */
}
catch (IOException ex) {
/* ... */
}
return out.toString();
}
}
Are you looking for http://docs.oracle.com/javase/6/docs/api/java/util/zip/ZipInputStream.html which can extract entries in zip file without extracting it completely.
I want to have a program that reads metadata from an MP3 file. My program should also able to edit these metadata. What can I do?
I got to search out for some open source code. But they have code; but not simplified idea for my job they are going to do.
When I read further I found the metadata is stored in the MP3 file itself. But I am yet not able to make a full idea of my baby program.
Any help will be appreciated; with a program or very idea (like an algorithm). :)
The last 128 bytes of a mp3 file contains meta data about the mp3 file., You can write a program to read the last 128 bytes...
UPDATE:
ID3v1 Implementation
The Information is stored in the last 128 bytes of an MP3. The Tag
has got the following fields, and the offsets given here, are from
0-127.
Field Length Offsets
Tag 3 0-2
Songname 30 3-32
Artist 30 33-62
Album 30 63-92
Year 4 93-96
Comment 30 97-126
Genre 1 127
WARINING- This is just an ugly way of getting metadata and it might not actually be there because the world has moved to id3v2. id3v1 is actually obsolete. Id3v2 is more complex than this, so ideally you should use existing libraries to read id3v2 data from mp3s . Just putting this out there.
You can use apache tika Java API for meta-data parsing from MP3 such as title, album, genre, duraion, composer, artist and etc.. required jars are tika-parsers-1.4, tika-core-1.4.
Sample Program:
package com.parse.mp3;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.parser.mp3.Mp3Parser;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class AudioParser {
/**
* #param args
*/
public static void main(String[] args) {
String fileLocation = "G:/asas/album/song.mp3";
try {
InputStream input = new FileInputStream(new File(fileLocation));
ContentHandler handler = new DefaultHandler();
Metadata metadata = new Metadata();
Parser parser = new Mp3Parser();
ParseContext parseCtx = new ParseContext();
parser.parse(input, handler, metadata, parseCtx);
input.close();
// List all metadata
String[] metadataNames = metadata.names();
for(String name : metadataNames){
System.out.println(name + ": " + metadata.get(name));
}
// Retrieve the necessary info from metadata
// Names - title, xmpDM:artist etc. - mentioned below may differ based
System.out.println("----------------------------------------------");
System.out.println("Title: " + metadata.get("title"));
System.out.println("Artists: " + metadata.get("xmpDM:artist"));
System.out.println("Composer : "+metadata.get("xmpDM:composer"));
System.out.println("Genre : "+metadata.get("xmpDM:genre"));
System.out.println("Album : "+metadata.get("xmpDM:album"));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (TikaException e) {
e.printStackTrace();
}
}
}
For J2ME(which is what I was struggling with), here's the code that worked for me..
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.lcdui.*;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.MetaDataControl;
import javax.microedition.midlet.MIDlet;
public class MetaDataControlMIDlet extends MIDlet implements CommandListener {
private Display display = null;
private List list = new List("Message", List.IMPLICIT);
private Command exitCommand = new Command("Exit", Command.EXIT, 1);
private Alert alert = new Alert("Message");
private Player player = null;
public MetaDataControlMIDlet() {
display = Display.getDisplay(this);
alert.addCommand(exitCommand);
alert.setCommandListener(this);
list.addCommand(exitCommand);
list.setCommandListener(this);
//display.setCurrent(list);
}
public void startApp() {
try {
FileConnection connection = (FileConnection) Connector.open("file:///e:/breathe.mp3");
InputStream is = null;
is = connection.openInputStream();
player = Manager.createPlayer(is, "audio/mp3");
player.prefetch();
player.realize();
} catch (Exception e) {
alert.setString(e.getMessage());
display.setCurrent(alert);
e.printStackTrace();
}
if (player != null) {
MetaDataControl mControl = (MetaDataControl) player.getControl("javax.microedition.media.control.MetaDataControl");
if (mControl == null) {
alert.setString("No Meta Information");
display.setCurrent(alert);
} else {
String[] keys = mControl.getKeys();
for (int i = 0; i < keys.length; i++) {
list.append(keys[i] + " -- " + mControl.getKeyValue(keys[i]), null);
}
display.setCurrent(list);
}
}
}
public void commandAction(Command cmd, Displayable disp) {
if (cmd == exitCommand) {
notifyDestroyed();
}
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
}