This Java DataSymbol Barcode Reader SDK is a wrapper for barcode decoding library (libdsdecoder.so.1 on Linux, BarcodeReader.dll on Windows). This wrapper works with native barcode library through JNI interface.

Installation

Copy the Java library in required folder of your machine.

· Linux/MacOS

copy "libjnidsdecoder.so" file in "/usr/lib" folder or any other folder where Java finds required libraries.

· Windows

copy "jnidsdecoder.dll" file in "windows/system32" folder or any other folder where Java finds required libraries.

Directory Structure

The Java SDK contains the following directories and files:

Java/ libjnidsdecoder.so (on Linux)

Java/jnidsdecoder.dll (on Windows)

Java JNI library.

Java/src/main.java

Simple Java example

Java/src/com/datasymbol/barcodereader/

BarcodeReaderWrapper.java

DecoderParameters.java

DecodingResult.java

The Java Barcode Reader classes

Getting Started

The usage of the library is very simple. Here below, please, find the typical sample of the library usage.

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import com.datasymbol.barcodereader.BarcodeReaderWrapper;

import com.datasymbol.barcodereader.DecoderParameters;

import com.datasymbol.barcodereader.DecodingResult;

class Main

{

public static void main(String[] args) throws IOException

{

BarcodeReaderWrapper dec = new BarcodeReaderWrapper();

boolean b = dec.InitLib("");

if(!b)

{

System.out.println(String.format("Error: %d", dec.decError));

return;

}

//set decoder parameters

DecoderParameters dp = new DecoderParameters();

dp.barcodeTypes |= DecoderParameters.ST_DATAMATRIX;

b = dec.SetParams(dp);

//read file

Path path = Paths.get("img_lin.pgm");

byte[] data = Files.readAllBytes(path);

//decode

DecodingResult res[] = dec.DecodePgm(data, 0, 0, 0, 0);

for(int j=0; res!=null && j < res.length; ++j)

{

String sBarcode = new String( res[j].data, 0, res[j].data.length );

System.out.println(sBarcode);

}

BarcodeReaderWrapper class

InitLib

Initializes library. You need to call this method before any else.

Syntax

boolean InitLib(String sKey);

Parameters

sKey	Library key.

Return Value

True if no errors, otherwise see decError member.

Decode

Decodes one frame. The frame is a byte matrix. Each byte has the value from 0 to 255 and represents one image pixel. 0 means a black pixel, 255 means a white pixel. Pixels are placed from the left to the right, from top to bottom, row by row.

The matrix is passed to the Decode method as a one-dimensional array. The first upper line of the image is sent first, then comes the second line and so on.

See the picture below for explanation.

Syntax

DecodingResult[] Decode( byte[] graymapImage, int width, int height, int left, int

top, int right, int bottom );

Parameters

graymapImage	pointer to the frame array
width	frame width
height	frame height
Left,top,right,bottom	scanning zone rectangle, if all of these are null then scan whole frame

Return Value

DecodingResult Array or null if no barcodes.

DecodePgm

Decodes .pgm file.

Syntax

DecodingResult[] DecodePgm( byte[] pgmImg, int left, int top, int right, int bottom );

Parameters

pgmImg	pointer to the .pgm file in memory
Left,top,right,bottom	scanning zone rectangle, if all of these are null then scan whole frame

Return Value

DecodingResult Array or null if no barcodes.

SetParams

Sets all decoder properties.

Syntax

boolean SetParams(DecoderParameters dp);

Parameters

dp	DecoderParameters structure

Return Value

True if no errors, otherwise see decError member

decError

If some functions returns the negative result check this field to get the error code.

Error Codes

Constant	Value	Description
BR_OK	0	Ok
BR_ERROR	1	Error
BR_NULL_DATA	2	Data to encode is null
BR_DATA_ERR_LEN	3	byte array length doesn't match the width and height
BR_CANT_GET_ARRAY	4	unable to get byte array elements
BR_LIB_NOT_INIT	5	Library is not initialized
BR_DECODING_ERR	6	Error during decoding
BR_PACK_RESULT	7	cannot pack decoding result
BR_CANT_CREATE_DECODER	8	cannot create barcode decoder object
BR_ERR_INPUT	9	invalid input parameter

DecoderParameters class

DecoderParameters members

Sets all decoder properties.

General
barcodeTypes	Sets what types of barcodes should be decoded. Each barcode type has specified integer value. The BarcodeTypes property can consist of any combination of these values, you should use the OR for that. Example: barcodeTypes = BR_ST_PDF417\|BR_ST_QRCODE;
inverseType	Sets what barcodes should be decoded (darks on light or lights on dark).
frameTime	Time to decode 1 frame in milliseconds. Default value - 0 (unlimited).
Linear
bLinearShowSymbologyID	Sets the value determining whether to add Symbology ID to the barcode text or not.
uiLinearFindBarcodes	Sets how many Linear barcodes should be decoded on the image. An image may contain one or several barcodes. Works only in Professional edition, Standard decodes only one barcode.
bLinearVerifyCheckDigit	Sets the value determining whether to verify the optional check digit in barcodes where this check digit is optional.
bLinearShowCheckDigit	Show the check digit or not.
bLinearShowStartStop	Show the start/stop characters or not. Some barcode types have start/stop characters (for example, Code39).
bLinearCode39EnableExtended	Decode Code 39 as Code 39 Extended or not.
bLinearUPCE2UPCA	Convert a UPC-E barcode to UPC-A or not.
uiLinearInterl25MinLen	The minimum length of an Interleaved 2/5 barcode. If the length of a read barcode is less than this value, the barcode is considered unrecognized.
uiLinearInterl25MaxLen	The maximum length of an Interleaved 2/5 barcode.
uiLinearIndustr25MinLen	The minimum length of an Industrial 2/5 barcode.
uiLinearIndustr25MaxLen	The maximum length of an Industrial 2/5 barcode.
uiLinearCode11MinLen	The minimum length of a Code11 barcode.
uiLinearCode11MaxLen	The maximum length of a Code11 barcode.
uiLinearCode39MinLen	The minimum length of a Code39 barcode.
uiLinearCode39MaxLen	The maximum length of a Code39 barcode.
uiLinearCode128MinLen	The minimum length of a Code128 barcode.
uiLinearCode128MaxLen	The maximum length of a Code128 barcode.
uiLinearCodabarMinLen	The minimum length of a Codabar barcode.
uiLinearCodabarMaxLen	The maximum length of a Codabar barcode.
uiLinearCode93MinLen	The minimum length of a Code93 barcode.
uiLinearCode93MaxLen	The maximum length of a Code93 barcode.
LinearDecSpeed	Linear barcode reading speed. Possible values: · 0 - Normal · 1 - Fast · 2 - Slow
PDF417
uiPDF417FindBarcodes	Sets how many PDF417 barcodes should be decoded on the image.
PDF417DecSpeed	PDF417 barcode reading speed.
bPDF417SymbologyID	Add Symbology ID to the barcode text or not.
bPDF417FindMicro	Finds Micro PDF417 barcodes. Default value - false
bPDF417Robust	Activates the robust PDF417 decoder mode. This property can help to decode high distorted PDF417 barcodes. Default value - false
DataMatrix
uiDataMatrixFindBarcodes	Sets how many DataMatrix barcodes should be decoded on the image.
DataMatrixDecSpeed	DataMatrix barcode reading speed.
bDataMatrixSymbologyID	Add Symbology ID to the barcode text or not.
DataMatrixInverseType	What barcodes should be decoded (darks on light or lights on dark).
bDataMatrixSupportECI	Support or not ECI (Extended Channel Interpretation).
QRCode
uiQRCodeFindBarcodes	Sets how many QRCode barcodes should be decoded on the image.
QRCodeDecSpeed	QRCode barcode reading speed.
bQRCodeSymbologyID	Add Symbology ID to the barcode text or not.
bQRCodeFindMicro	Finds Micro QRCode barcodes.
AztecCode
uiAztecCodeFindBarcodes	Sets how many AztecCode barcodes should be decoded on the image.
AztecCodeDecSpeed	AztecCode barcode reading speed.
bAztecCodeSymbologyID	Add Symbology ID to the barcode text or not.

DecoderParameters Barcode Types

Barcode Type	Value	Constant
Code 128	0x00000001	ST_CODE128
Code 39	0x00000002	ST_CODE39
Interleaved 2/5	0x00000004	ST_INTERL25
EAN-13	0x00000008	ST_EAN13
EAN-8	0x00000010	ST_EAN8
Codabar	0x00000020	ST_CODABAR
Code 11	0x00000040	ST_CODE11
UPC-A	0x00000080	ST_UPCA
UPC-E	0x00000100	ST_UPCE
Industrial 2/5	0x00000200	ST_INDUSTR25
Code 93	0x00000400	ST_CODE93
DataBar omnidirectional, DataBar Truncated	0x00000800	ST_DATABAR_OMNI
DataBar limited	0x00001000	ST_DATABAR_LIM
DataBar stacked	0x00002000	ST_DATABAR_STACKED
DataBar Expanded	0x00004000	ST_DATABAR_EXP
DataBar Expanded stacked	0x00008000	ST_DATABAR_EXP_STACKED
unrecognized linear	0x01000000	ST_LINEAR_UNDEC
unrecognized PDF417	0x02000000	ST_PDF417_UNDEC
unrecognized DataMatrix	0x04000000	ST_DATAMATRIX_UNDEC
unrecognized QRCode	0x08000000	ST_QRCODE_UNDEC
unrecognized AztecCode	0x00100000	ST_AZTECCODE_UNDEC
DataMatrix	0x10000000	ST_DATAMATRIX
PDF417	0x20000000	ST_PDF417
QRCode	0x40000000	ST_QRCODE
AztecCode	0x80000000	ST_AZTECCODE

DecodingResult class

DecodingResult members

Determines decoded barcode.

barcodeType	Barcode Type
data	Array of bytes of decoded barcode.
x1,y1, x2,y2, x3,y3, x4,y4	Barcode coordinates
rel	Returns the decoding quality (0...100). Works only for PDF417, DataMatrix, QRCode, AztecCode barcodes.