Develop Reference

Parallel Processing using Multi Threading in Java

I am creating a Web App in which, I have to upload files by splitting them using parallel processing and multi threading and while downloading I have to combine them back to a single file using multi threading and parallel processing.
I want to combine split files into a single. But its not working as I expected to work.
The number of threads created is equal to the number of parts the file have been split.
And the threads should run parallelly and should run only once. But the threads are called several times. Help me fix the code.
UploadServlet.java
import java.util.Arrays;
import java.nio.charset.StandardCharsets;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import org.apache.commons.io.IOUtils;
import jakarta.servlet.*;
import jakarta.servlet.annotation.MultipartConfig;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.Part;
import jakarta.servlet.http.HttpServletRequest;
import java.io.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
public class UploadServlet extends HttpServlet
{
private static final long serialVersionUID = 100L;
public static String fileName;
public static long size;
public static int noOfParts;
public static String type;
public static byte[] b;
private static final String INSERT_USERS_SQL = "INSERT INTO uploadlist" +
" (filename, filesize, noofparts) VALUES " +
"(?, ?, ?);";
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Part file = request.getPart("file");
fileName=file.getSubmittedFileName();
type=file.getContentType();
PrintWriter writer=response.getWriter();
file.write(fileName);
String n = request.getParameter("parts");
size = file.getSize();
Integer temp1 = Integer.parseInt(n);
noOfParts = temp1.intValue();
set();
writer.println("File Uploaded Successfully");
file.delete();
}
public static void set()
{
Split.split(fileName,size,noOfParts);
try {
Connection c = DataBaseConnection.getConnection();
PreparedStatement preparedStatement = c.prepareStatement(INSERT_USERS_SQL);
preparedStatement.setString(1, fileName);
preparedStatement.setLong(2, size);
preparedStatement.setInt(3, noOfParts);
System.out.println(preparedStatement);
preparedStatement.executeUpdate();
} catch (Exception e)
{
e.printStackTrace();
}
}
}
From UploadServlet Split.split() is called to split the files into number of parts.
Split.java
import java.io.*;
import java.util.Arrays;
public class Split implements Runnable
{
int i;
long size;
int noOfParts;
String fileName;
Split()
{
fileName="";
}
Split(String fileName, int i, long size, int noOfParts)
{
this.fileName=fileName;
this.i=i;
this.size=size;
this.noOfParts=noOfParts;
}
public void run()
{
try
{
System.out.println(i);
RandomAccessFile in = new RandomAccessFile("D:\\temp\\"+fileName,"r");
int bytesPerSplit = (int)(size/noOfParts);
int remainingBytes = (int)(size % noOfParts);
byte[] b;
if(i!=noOfParts-1)
{
b = new byte[bytesPerSplit];
}
else
{
b = new byte[bytesPerSplit+remainingBytes];
}
in.seek((long)i*bytesPerSplit);
in.read(b);
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("D:\\Upload\\"+fileName+i+".bin"));
for(byte temp : b)
out.write(temp);
out.close();
}
catch(IOException e)
{
e.printStackTrace();
}
}
public static void split(String fileName, long size, int noOfParts)
{
for(int i=0; i<noOfParts; i++)
{
Split obj = new Split(fileName,i,size,noOfParts);
Thread t = new Thread(obj);
t.start();
}
}
}
In this program, I split the files according to number of parts. And I want to combine them back using Parallel Processing and Multi Threading.
DownloadServlet.java\
import jakarta.servlet.http.HttpServlet;
import org.postgresql.Driver;
import java.sql.Statement;
import java.io.*;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.DriverManager;
import java.util.Arrays;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
public class DownloadServlet extends HttpServlet
{
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
String name = new String(request.getParameter("fileName"));
int noOfParts = Integer.parseInt(request.getParameter("parts"));
int size = Integer.parseInt(request.getParameter("size"));
File downloadFile = new File("D:\\Download\\"+name);
Combine.combine(name,noOfParts,size);
int length = (int)downloadFile.length();
String completeFile=name;
ServletContext context=getServletContext();
String mimeType = context.getMimeType(completeFile);
if (mimeType == null)
{
mimeType = "application/octet-stream";
}
response.setContentType(mimeType);
response.setContentLength((int)length);
String headerKey = "Content-Disposition";
String headerValue = String.format("attachment; filename=\"%s\"", completeFile);
response.setHeader(headerKey, headerValue);
OutputStream outStream = response.getOutputStream();
DataInputStream in = new DataInputStream(new FileInputStream(downloadFile));
byte[] buffer = new byte[(int)length];
while ((in != null) && ((length = in.read(buffer)) != -1))
{
outStream.write(buffer,0,length);
}
if ((length = in.read(buffer))== -1) {
outStream.write(buffer, 0, length);
}
Arrays.fill(buffer, (byte)0);
in.close();
outStream.flush();
outStream.close();
}
}
From DownloadServlet, Combine.combine() is called to combine the split parts into a single file.
Combine.java
import java.io.*;
import java.util.concurrent.TimeUnit;
import java.util.*;
import org.apache.commons.lang3.StringUtils;
import java.util.regex.*;
import java.util.Scanner;
import java.util.Arrays;
public class Combine implements Runnable
{
String name;
int size;
int noOfParts;
int i;
public static String root = "D:\\Upload\\";
Combine(String name,int noOfParts,int size, int i)
{
this.name = name;
this.noOfParts=noOfParts;
this.size=size;
this.i=i;
}
public void run()
{
try
{
System.out.println(i);
RandomAccessFile out = new RandomAccessFile("D:\\Download\\"+name,"rw");
int bytesPerSplit = size/noOfParts;
int remainingBytes = size%noOfParts;
String temp=name+i+".bin";
RandomAccessFile file = new RandomAccessFile(root+temp,"r");
long l=file.length();
byte[] b = new byte[(int)l];
file.read(b);
out.seek(i*bytesPerSplit);
out.write(b);
file.close();
out.close();
}
catch(IOException e)
{
e.printStackTrace();
}
}
public static void combine(String name, int noOfParts, int size)
{
for(int i=0; i<noOfParts; i++)
{
Combine obj = new Combine(name,noOfParts,size,i);
Thread t = new Thread(obj,"Thread"+i);
t.start();
}
}
}
I have attached the image in which the numbers represent the part of the file being read and combined using threads.
The output shows that the threads keeping on executing again and again.
I don't know where is the error or any logical mistake in my program.
Help me solve this problem.

How to read data serialized with Chronicle Wire from InputStream?

Some data are serialized to an outputstream via Chronicle Wire.
Object m = ... ;
OutputStream out = ... ;
WireType.RAW //
.apply(Bytes.elasticByteBuffer()) //
.getValueOut().object(m) //
.bytes().copyTo(out)
;
I want to get them back from an Inputstream.
InputStream in = ... ;
WireType.RAW
.apply(Bytes.elasticByteBuffer())
.getValueIn()
???
;
Object m = ???; // How to initialize m ?
How to read my initial object m from in ?

There is an assumption you will have some idea of how long the data is and read it in one go. It is also assumed you will want to reuse the buffers to avoid creating garbage. To minimise latency data is typical read to/from NIO Channels.
I have raised an issue to create this example, Improve support for Input/OutputStream and non Marshallable objects https://github.com/OpenHFT/Chronicle-Wire/issues/111
This should do what you want efficiently without creating garbage each time.
package net.openhft.chronicle.wire;
import net.openhft.chronicle.bytes.Bytes;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
public class WireToOutputStream {
private final Bytes<ByteBuffer> bytes = Bytes.elasticHeapByteBuffer(128);
private final Wire wire;
private final DataOutputStream dos;
public WireToOutputStream(WireType wireType, OutputStream os) {
wire = wireType.apply(bytes);
dos = new DataOutputStream(os);
}
public Wire getWire() {
wire.clear();
return wire;
}
public void flush() throws IOException {
int length = Math.toIntExact(bytes.readRemaining());
dos.writeInt(length);
dos.write(bytes.underlyingObject().array(), 0, length);
}
}
package net.openhft.chronicle.wire;
import net.openhft.chronicle.bytes.Bytes;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StreamCorruptedException;
import java.nio.ByteBuffer;
public class InputStreamToWire {
private final Bytes<ByteBuffer> bytes = Bytes.elasticHeapByteBuffer(128);
private final Wire wire;
private final DataInputStream dis;
public InputStreamToWire(WireType wireType, InputStream is) {
wire = wireType.apply(bytes);
dis = new DataInputStream(is);
}
public Wire readOne() throws IOException {
wire.clear();
int length = dis.readInt();
if (length < 0) throw new StreamCorruptedException();
bytes.ensureCapacity(length);
byte[] array = bytes.underlyingObject().array();
dis.readFully(array, 0, length);
bytes.readPositionRemaining(0, length);
return wire;
}
}
You can then do the following
package net.openhft.chronicle.wire;
import net.openhft.chronicle.core.util.ObjectUtils;
import org.junit.Test;
import java.io.IOException;
import java.io.Serializable;
import java.net.ServerSocket;
import java.net.Socket;
import static org.junit.Assert.assertEquals;
public class WireToOutputStreamTest {
#Test
public void testVisSocket() throws IOException {
ServerSocket ss = new ServerSocket(0);
Socket s = new Socket("localhost", ss.getLocalPort());
Socket s2 = ss.accept();
WireToOutputStream wtos = new WireToOutputStream(WireType.RAW, s.getOutputStream());
Wire wire = wtos.getWire();
AnObject ao = new AnObject();
ao.value = 12345;
ao.text = "Hello";
// write the type is needed.
wire.getValueOut().typeLiteral(AnObject.class);
Wires.writeMarshallable(ao, wire);
wtos.flush();
InputStreamToWire istw = new InputStreamToWire(WireType.RAW, s2.getInputStream());
Wire wire2 = istw.readOne();
Class type = wire2.getValueIn().typeLiteral();
Object ao2 = ObjectUtils.newInstance(type);
Wires.readMarshallable(ao2, wire2, true);
System.out.println(ao2);
ss.close();
s.close();
s2.close();
assertEquals(ao.toString(), ao2.toString());
}
public static class AnObject implements Serializable {
long value;
String text;
#Override
public String toString() {
return "AnObject{" +
"value=" + value +
", text='" + text + '\'' +
'}';
}
}
}
Sample code
// On Sender side
Object m = ... ;
OutputStream out = ... ;
WireToOutputStream wireToOutputStream = new
WireToOutputStream(WireType.TEXT, out);
Wire wire = wireToOutputStream.getWire();
wire.getValueOut().typeLiteral(m.getClass());
Wires.writeMarshallable(m, wire);
wireToOutputStream.flush();
// On Receiver side
InputStream in = ... ;
InputStreamToWire inputStreamToWire = new InputStreamToWire(WireType.TEXT, in);
Wire wire2 = inputStreamToWire.readOne();
Class type = wire2.getValueIn().typeLiteral();
Object m = ObjectUtils.newInstance(type);
Wires.readMarshallable(m, wire2, true);
This code is a lot simpler if your DTO extends Marshallable but this will work whether you extend an interface or not. i.e. you don't need to extend Serializable.
Also if you know what the type will be you don't need to write it each time.
The helper classes above have been added to the latest SNAPSHOT

java save http post requests hourly

I'm trying to set up a server on aws with simple http server and save each http post request headers & payload.
It works locally.
My steps after connection via ssh to the ec2 server:
javac Server.java
sudo nohup java Server
It saves the headers to log file but not the payload and it doesn't returns 204 response.
Server.java
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.URLDecoder;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Executors;
public class Server {
private static final int PORT = 80;
private static final String FILE_PATH = "/home/ec2-user/logs/";
private static final String UTF8 = "UTF-8";
private static final String DELIMITER = "|||";
private static final String LINE_BREAK = "\n";
private static final String FILE_PREFIX = "dd_MM_YYYY_HH";
private static final SimpleDateFormat simpleDateFormat = new SimpleDateFormat(FILE_PREFIX);
private static final String FILE_TYPE = ".txt";
public static void main(String[] args) {
try {
HttpServer server = HttpServer.create(new InetSocketAddress(PORT), 0);
server.createContext("/", new HttpHandler() {
#Override
public void handle(HttpExchange t) throws IOException {
System.out.println("Req\t" + t.getRemoteAddress());
InputStream initialStream = t.getRequestBody();
byte[] buffer = new byte[initialStream.available()];
initialStream.read(buffer);
File targetFile = new File(FILE_PATH + simpleDateFormat.format(new Date()) + FILE_TYPE);
OutputStream outStream = new FileOutputStream(targetFile, true);
String prefix = LINE_BREAK + t.getRequestHeaders().entrySet().toString() + LINE_BREAK + System.currentTimeMillis() + DELIMITER;
outStream.write(prefix.getBytes());
Map<String, String> queryPairs = new HashMap<>();
String params = new String(buffer);
String[] pairs = params.split("&");
for (String pair : pairs) {
int idx = pair.indexOf("=");
String key = pair.substring(0, idx);
String val = pair.substring(idx + 1);
String decodedKey = URLDecoder.decode(key, UTF8);
String decodeVal = URLDecoder.decode(val, UTF8);
queryPairs.put(decodedKey, decodeVal);
}
outStream.write(queryPairs.toString().getBytes());
t.sendResponseHeaders(204, -1);
t.close();
}
});
server.setExecutor(Executors.newCachedThreadPool());
server.start();
} catch (Exception e) {
System.out.println("Exception: " + e.getMessage());
e.printStackTrace();
}
}
}

Consider these changes to your handle method. As a starting point, two things are changed:
It reads the complete input and copies that into your file (initialStream.available() might not be the full truth)
catch, log and rethrow IOExceptions (you didn't see your 204 after all)
Consider redirecting your output into files, so you can check what happend on server later:
sudo nohup java Server > server.log 2> server.err &
If you described in more detail the desired target file structure we could figure something out there as well I guess.
#Override
public void handle(HttpExchange t) throws IOException {
try {
System.out.println("Req\t" + t.getRemoteAddress());
InputStream initialStream = t.getRequestBody();
File targetFile = new File(FILE_PATH + simpleDateFormat.format(new Date()) + FILE_TYPE);
OutputStream outStream = new FileOutputStream(targetFile, true);
// This will copy ENTIRE input stream into your target file
IOUtils.copy(initialStream, outStream);
outStream.close();
t.sendResponseHeaders(204, -1);
t.close();
} catch(IOException e) {
e.printStackTrace();
throw e;
}
}

Java How To Separate A Text File To Files By Separator String

I Want to separate a text file with separator.
Example
BEGIN:VCARD
VERSION:2.1
X-TIMES_CONTACTED:2
X-LAST_TIME_CONTACTED:1438878121912
N:SomeOne
FN:...
TEL;CELL:111122222
TEL;CELL:333334444
PHOTO;ENCODING=BASE64;JPEG:/...CfbNQMCwwBk1ZtrKadgEXNNC2P/Z
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:Another
FN:Victim
TEL;CELL:888888888888
TEL;CELL:99999999
END:VCARD
with method : SplitFile("c:\test\test.vcf", "END:VCARD", "c:\test\output");

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import org.apache.commons.io.FilenameUtils;
public class MainClass {
public static void main(String[] args) {
SplitFile("c:\\test\\test.vcf", "END:VCARD", "c:\\test\\output");
}
private static void SplitFile(String fileName, String seperateChars, String destFolder) {
try {
Path p = Paths.get(fileName);// or
// FileSystems.getDefault().getPath(fileName)
String lines = new String(Files.readAllBytes(p));
String fName = FilenameUtils.getBaseName(p.toString());
String fExt = FilenameUtils.getExtension(p.toString());
int fCounter = 0;
int beginMark = 0;
int endMark = 0;
destFolder = FilenameUtils.normalizeNoEndSeparator(destFolder);
while ((endMark = lines.indexOf(seperateChars, beginMark)) >= 0) {
fCounter++;
String buf = lines.substring(beginMark, endMark + seperateChars.length());
String fOut = String.format("%s\\%s%05d.%s", destFolder, fName, fCounter, fExt);
System.out.println(fOut);
beginMark = endMark + seperateChars.length();
Files.write(Paths.get(fOut), buf.getBytes(), StandardOpenOption.CREATE);
endMark = -1;
}
System.out.println("Done!");
} catch (IOException e) {
e.printStackTrace();
}
}
}

Reading QRCode with Zxing in Java

Some questions about using Zxing...
I write the following code to read barcode from an image:
public class BarCodeDecode
{
/**
* #param args
*/
public static void main(String[] args)
{
try
{
String tmpImgFile = "D:\\FormCode128.TIF";
Map<DecodeHintType,Object> tmpHintsMap = new EnumMap<DecodeHintType, Object>(DecodeHintType.class);
tmpHintsMap.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
tmpHintsMap.put(DecodeHintType.POSSIBLE_FORMATS, EnumSet.allOf(BarcodeFormat.class));
tmpHintsMap.put(DecodeHintType.PURE_BARCODE, Boolean.FALSE);
File tmpFile = new File(tmpImgFile);
String tmpRetString = BarCodeUtil.decode(tmpFile, tmpHintsMap);
//String tmpRetString = BarCodeUtil.decode(tmpFile, null);
System.out.println(tmpRetString);
}
catch (Exception tmpExpt)
{
System.out.println("main: " + "Excpt err! (" + tmpExpt.getMessage() + ")");
}
System.out.println("main: " + "Program end.");
}
}
public class BarCodeUtil
{
private static BarcodeFormat DEFAULT_BARCODE_FORMAT = BarcodeFormat.CODE_128;
/**
* Decode method used to read image or barcode itself, and recognize the barcode,
* get the encoded contents and returns it.
* #param whatFile image that need to be read.
* #param config configuration used when reading the barcode.
* #return decoded results from barcode.
*/
public static String decode(File whatFile, Map<DecodeHintType, Object> whatHints) throws Exception
{
// check the required parameters
if (whatFile == null || whatFile.getName().trim().isEmpty())
throw new IllegalArgumentException("File not found, or invalid file name.");
BufferedImage tmpBfrImage;
try
{
tmpBfrImage = ImageIO.read(whatFile);
}
catch (IOException tmpIoe)
{
throw new Exception(tmpIoe.getMessage());
}
if (tmpBfrImage == null)
throw new IllegalArgumentException("Could not decode image.");
LuminanceSource tmpSource = new BufferedImageLuminanceSource(tmpBfrImage);
BinaryBitmap tmpBitmap = new BinaryBitmap(new HybridBinarizer(tmpSource));
MultiFormatReader tmpBarcodeReader = new MultiFormatReader();
Result tmpResult;
String tmpFinalResult;
try
{
if (whatHints != null && ! whatHints.isEmpty())
tmpResult = tmpBarcodeReader.decode(tmpBitmap, whatHints);
else
tmpResult = tmpBarcodeReader.decode(tmpBitmap);
// setting results.
tmpFinalResult = String.valueOf(tmpResult.getText());
}
catch (Exception tmpExcpt)
{
throw new Exception("BarCodeUtil.decode Excpt err - " + tmpExcpt.toString() + " - " + tmpExcpt.getMessage());
}
return tmpFinalResult;
}
}
I try to read the following two images that contains code128 and QRCode.
It can work for the code128 but not for the QRCode.
Any one knows why...

Please go through this link for complete Tutorial. The author of this code is Joe. I have not developed this code, so I am just doing Copy paste to make sure this is available in case link is broken.
The author is using ZXing(Zebra Crossing Library) you can download it from here, for this tutorial.
QR Code Write and Read Program in Java:
package com.javapapers.java;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
public class QRCode {
public static void main(String[] args) throws WriterException, IOException,
NotFoundException {
String qrCodeData = "Hello World!";
String filePath = "QRCode.png";
String charset = "UTF-8"; // or "ISO-8859-1"
Map<EncodeHintType, ErrorCorrectionLevel> hintMap = new HashMap<EncodeHintType, ErrorCorrectionLevel>();
hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
createQRCode(qrCodeData, filePath, charset, hintMap, 200, 200);
System.out.println("QR Code image created successfully!");
System.out.println("Data read from QR Code: "
+ readQRCode(filePath, charset, hintMap));
}
public static void createQRCode(String qrCodeData, String filePath,
String charset, Map hintMap, int qrCodeheight, int qrCodewidth)
throws WriterException, IOException {
BitMatrix matrix = new MultiFormatWriter().encode(
new String(qrCodeData.getBytes(charset), charset),
BarcodeFormat.QR_CODE, qrCodewidth, qrCodeheight, hintMap);
MatrixToImageWriter.writeToFile(matrix, filePath.substring(filePath
.lastIndexOf('.') + 1), new File(filePath));
}
public static String readQRCode(String filePath, String charset, Map hintMap)
throws FileNotFoundException, IOException, NotFoundException {
BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(
new BufferedImageLuminanceSource(
ImageIO.read(new FileInputStream(filePath)))));
Result qrCodeResult = new MultiFormatReader().decode(binaryBitmap,
hintMap);
return qrCodeResult.getText();
}
}
Maven dependency for the ZXing QR Code library:
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>2.2</version>
</dependency>

Curiously your code works for me, but I had to remove the follow hint.
tmpHintsMap.put(DecodeHintType.PURE_BARCODE, Boolean.FALSE);
When my image is not pure barcode, this hint broke my result.
Thank you!

This Code worked for me.
public static List<string> ScanForBarcodes(string path)
{
return ScanForBarcodes(new Bitmap(path));
}
public static List<string> ScanForBarcodes(Bitmap bitmap)
{
// initialize a new Barcode reader.
BarcodeReader reader = new BarcodeReader
{
TryHarder = true, // TryHarder is slower but recognizes more Barcodes
PossibleFormats = new List<BarcodeFormat> // in the ZXing There is an Enum where all supported barcodeFormats were contained
{
BarcodeFormat.CODE_128,
BarcodeFormat.QR_CODE,
//BarcodeFormat. ... ;
}
};
return reader.DecodeMultiple(bitmap).Select(result => result.Text).ToList(); // return only the barcode string.
// If you want the full Result use: return reader.DecodeMultiple(bitmap);
}
Did you use this (ZXing.Net) Lib?