×
MENU
Resources Base
Table of contents

Server-side Scripting

DWT is a 100% client-side library. However, it does need to interact with the server when doing operations like Upload, Download, Server-side OCR, etc. While the scripts are scattered in the documentation, we’ll try to cover some important ones in this article.

How to process uploaded files

As mentioned in how to upload, DWT sends an HTTP POST request to the server when doing an upload. The file in the POST Form has the name RemoteFile by default. If you wish to change that, you can use HttpFieldNameOfUploadedImage .

The following assumes the default RemoteFile is used and that extra Form fields might accompany the file.

Upload via CSharp

Regular upload

string strImageName, strImageSize;
HttpFileCollection files = HttpContext.Current.Request.Files;
/**
 * Writes the file to the disk
 */
HttpPostedFile uploadfile = files["RemoteFile"];
strImageName = uploadfile.FileName;
string strImageSavePath = Server.MapPath(".") + "\\Dynamsoft_Upload\\";
if (!System.IO.Directory.Exists(strImageSavePath))
{
    System.IO.Directory.CreateDirectory(strImageSavePath);
}
String strInputFile = strImageSavePath + strImageName;
uploadfile.SaveAs(strInputFile);
/**
 * The following writes the fields to a file
 */
string path = strInputFile.Substring(0, strInputFile.Length - 4) + "_1.txt";
int fieldsCount = HttpContext.Current.Request.Form.Count;
if(fieldsCount > 0){
    if (!System.IO.File.Exists(path))
    {
        using (System.IO.FileStream fs = new System.IO.FileStream(path, System.IO.FileMode.Create, System.IO.FileAccess.Write))
        {
            using (System.IO.StreamWriter sw = new System.IO.StreamWriter(fs, Encoding.UTF8))
            {
                for (int i = 0; i < fieldsCount; i++)
                {
                    // Create a file to write to.
                    sw.WriteLine(HttpContext.Current.Request.Form.Keys[i] + " :  " + HttpContext.Current.Request.Form[HttpContext.Current.Request.Form.Keys[i]] + Environment.NewLine);
                }
            }
        }
    }
}

Segmented upload

String filename = Request["filename"];
String range = Request.Headers["Content-Range"];
String md5 = Request.Headers["dwt-md5"];
if (range != null)
{
    /**
     * The header "Content-Range" signals that it's segmented
     * The following stitches the segments together.
     */
    string[] ary = range.Replace("bytes ", "").Replace("-", "/").Split('/');
    int start, end, size;
    start = Convert.ToInt32(ary[0]);
    end = Convert.ToInt32(ary[1]);
    size = Convert.ToInt32(ary[2]);
    String strImageName = "";
    HttpFileCollection files = HttpContext.Current.Request.Files;
    HttpPostedFile uploadfile = files["RemoteFile"];
        if (!Directory.Exists(Server.MapPath(".") + "\\Images"))
            Directory.CreateDirectory(Server.MapPath(".") + "\\Images");
    if (filename == null || filename == "")
        filename = uploadfile.FileName;
    if (uploadfile != null)
    {
        if (!Directory.Exists(Server.MapPath(".") + "\\Images"))
            Directory.CreateDirectory(Server.MapPath(".") + "\\Images");
        strImageName = Server.MapPath(".") + "\\Images\\" + filename;
        Stream ifs = uploadfile.InputStream;
        byte[] bytes = null;
        bytes = new byte[ifs.Length];
        ifs.Read(bytes, 0, (int)ifs.Length);
        FileStream fs;
        if (File.Exists(strImageName))
        {
            fs = new FileStream(strImageName, FileMode.Open, FileAccess.Write, FileShare.ReadWrite);
        }
        else
        {
            fs = new FileStream(strImageName, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
        }
        if (start > fs.Length)
        {
            fs.Seek(0, SeekOrigin.End);

            for (long i = 0; i < (fs.Length - start); i++)
                fs.WriteByte(0);
        }
        fs.Seek(start, SeekOrigin.Begin);
        fs.Write(bytes, 0, bytes.Length);
        fs.Flush();
        fs.Close();
    }
}
else
{
    // Compatible with regular uploads
    HttpFileCollection files = HttpContext.Current.Request.Files;
    HttpPostedFile uploadfile = files["RemoteFile"];
    if (filename == null || filename == "")
    {
        filename = uploadfile.FileName;
    }
    uploadfile.SaveAs(Server.MapPath(".") + "\\Images\\" + filename);
}

Save to MS SQL

//Connect to SQL
String serverName = "YOUR-SERVER-NAME";
String userName = "test";
String password = "Aa000000";
String dbName = "dwtsample";
String tableName = "uploadedimages";
System.Data.SqlClient.SqlConnection tmpConn = new System.Data.SqlClient.SqlConnection("Data Source = " + serverName + ";User ID = " + userName + ";Pwd = " + password + ";");
String sqlCreateDBQuery = string.Format("SELECT database_id FROM sys.databases WHERE Name = '{0}'", dbName);
using (tmpConn)
{
    using (System.Data.SqlClient.SqlCommand sqlCmd = new System.Data.SqlClient.SqlCommand(sqlCreateDBQuery, tmpConn))
    {
        tmpConn.Open();
        object resultObj = sqlCmd.ExecuteScalar();
        int databaseID = 0;
        if (resultObj != null)
        {
            int.TryParse(resultObj.ToString(), out databaseID);
        }
        // Database doesn't exist, create one
        if (databaseID == 0)
        {
            String sql_newdb = "CREATE DATABASE " + dbName;
            using (System.Data.SqlClient.SqlCommand sqlcmd_newdb = new System.Data.SqlClient.SqlCommand(sql_newdb, tmpConn))
            {
                sqlcmd_newdb.ExecuteScalar();
            }
        }
    }
    tmpConn.Close();
}
System.Data.SqlClient.SqlConnection Connection = new System.Data.SqlClient.SqlConnection("Data Source = " + serverName + ";User ID = " + userName + ";Pwd = " + password + ";Initial Catalog =" + dbName + ";");
using (Connection)
{
    Connection.Open();
    String sql_checkTable = @"IF EXISTS(SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='" + tableName + "') SELECT 1 ELSE SELECT 0";
    using (System.Data.SqlClient.SqlCommand sqlcmd_checkTable = new System.Data.SqlClient.SqlCommand(sql_checkTable, Connection))
    {
        object result_obj = sqlcmd_checkTable.ExecuteScalar();
        int table_exists = 0;
        if (result_obj != null)
        {
            int.TryParse(result_obj.ToString(), out table_exists);
        }
        // Table doesn't exist, create one
        if (table_exists == 0)
        {
            String sql_newTable = @"CREATE TABLE " + tableName + " (id int NOT NULL IDENTITY (1, 1), document_name varchar(255) NOT NULL, document_data image NOT NULL) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]";
            using (System.Data.SqlClient.SqlCommand sqlcmd_newTable = new System.Data.SqlClient.SqlCommand(sql_newTable, Connection))
            {
                sqlcmd_newTable.ExecuteScalar();
            }
        }
    }
    /**
     * Convert the uploaded file to a byte array
     */
    int iFileLength;
    HttpFileCollection files = HttpContext.Current.Request.Files;
    HttpPostedFile uploadfile = files["RemoteFile"];
    String strImageName = uploadfile.FileName;
    iFileLength = uploadfile.ContentLength;
    Byte[] inputBuffer = new Byte[iFileLength];
    System.IO.Stream inputStream;
    inputStream = uploadfile.InputStream;
    inputStream.Read(inputBuffer, 0, iFileLength);
    inputStream.Close();
    /**
     * Save the byte array to the database
     */
    String sql_insertData = "INSERT INTO " + tableName + " (document_name, document_data) VALUES (@document_name, @document_data)";
    using (System.Data.SqlClient.SqlCommand sqlcmd_insertData = new System.Data.SqlClient.SqlCommand(sql_insertData, Connection))
    {
        sqlcmd_insertData.Parameters.Add("@document_data", System.Data.SqlDbType.Binary, iFileLength).Value = inputBuffer;
        sqlcmd_insertData.Parameters.Add("@document_name", System.Data.SqlDbType.VarChar, 255).Value = strImageName;
        sqlcmd_insertData.ExecuteScalar();
    }
    Connection.Close();
}

Upload via PHP

Upload and save to the disk

$fileTempName = $_FILES['RemoteFile']['tmp_name'];
$fileSize = $_FILES['RemoteFile']['size'];
$fileName = "Dynamsoft_Upload\\" . $_FILES['RemoteFile']['name'];
$fileName = iconv("UTF-8", "gb2312", $fileName);
$count = count($_POST);
if ($count > 0) {
    $_fieldsTXT = fopen(substr($fileName, 0, strlen($fileName) - 4) . "_1.txt", "w");
    $_fields = "";
    foreach ($_POST as $key => $value) {
        $_fields = "FieldsTrue:";
        fwrite($_fieldsTXT, $key . " :  " . $value . PHP_EOL);
    }
}

if (file_exists($fileName)) {
    $fWriteHandle = fopen($fileName, 'w');
} else {
    $fWriteHandle = fopen($fileName, 'w');
}

$fReadHandle = fopen($fileTempName, 'rb');
$fileContent = fread($fReadHandle, $fileSize);
fwrite($fWriteHandle, $fileContent);
fclose($fWriteHandle);

Save to MySQL

// Interacting with MySQL
$servername = "127.0.0.1";
$username = "root";
$password = "awesome";
$dbname = "dwtsample";
$tablename = "uploadedimages";
// Create connection
$conn = new mysqli($servername, $username, $password);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} else {
    // Check Database Existance
    $db_selected = mysqli_select_db($conn, $dbname);
    if(!$db_selected) {
        // Create database
        $sql_newDB = "CREATE DATABASE ".$dbname;
        if ($conn->query($sql_newDB) === TRUE) {
            // echo "Database created successfully";
        } else {
            die("Error creating database: " . $conn->error);
        }			
    }
    mysqli_select_db($conn, $dbname);
    // Check Table Existance
    $sql_showtable = "SHOW TABLES LIKE '".$tablename."'";
    $rowcount = mysqli_num_rows($conn->query($sql_showtable));
    if ($rowcount > 0) {
        // echo "the table exists";
    } else {
        // sql to create table
        $sql_newtable = "CREATE TABLE ".$tablename." (
        id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
        document_name VARCHAR(30) NOT NULL,
        document_data longblob NOT NULL,
        reg_date TIMESTAMP
        )";
        if ($conn->query($sql_newtable) === TRUE) {
        // echo "Table ".$tablename." created successfully";
        } else {
            die("Error creating table: " . $conn->error);
        }
    }
    $fileTempName = $_FILES['RemoteFile']['tmp_name'];	
    $fileSize = $_FILES['RemoteFile']['size'];
    $fileName = $_FILES['RemoteFile']['name'];
    $fReadHandle = fopen($fileTempName, 'rb');
    $fileContent = fread($fReadHandle, $fileSize);
    fclose($fReadHandle);
    $sql_insertdata = "INSERT INTO ".$tablename." (document_name,document_data) VALUES ('".$fileName."','".addslashes($fileContent)."')";
    if ($conn->query($sql_insertdata) === TRUE) {
        // echo "File saved in db successfully.";
    } else {
        die("Error saving file: " . $conn->error);
    }
    $conn->close();
}

Upload via JSP

Use JSP packages to save the uploaded file

The following packages are required

<%@  page language="java" import="java.io.*,java.util.*,org.apache.commons.fileupload.*,org.apache.commons.fileupload.disk.*,org.apache.commons.fileupload.servlet.*"%>

The code to save the file to the disk

// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
// Configure a repository (to ensure a secure temp location is used)
ServletContext servletContext = this.getServletConfig().getServletContext();
File repository = (File) servletContext.getAttribute("javax.servlet.context.tempdir");
// Set factory constraints
factory.setRepository(repository);
// Sets the threshold beyond which files are written to disk
factory.setSizeThreshold(1000000000);
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// Set overall request size constraint
upload.setSizeMax(-1);
// Parse the request
List<FileItem> items = upload.parseRequest(request);
// Process the uploaded items
Iterator<FileItem> iter = items.iterator();
String _fields = "";
String fileName = "";
long sizeInBytes = 0;
String _temp_Name = application.getRealPath("/Dynamsoft_Upload");
File _fieldsTXT = new File(_temp_Name);
if(!_fieldsTXT.exists())
{
    boolean result = _fieldsTXT.createNewFile();
    System.out.println("File create result:"+result);
}
Writer objWriter = new BufferedWriter(new FileWriter(_fieldsTXT));
while (iter.hasNext()) {
    FileItem item = iter.next();
    // Process a regular form field
    if (item.isFormField()) {
        _fields = "FieldsTrue:";			
        String fieldName = item.getFieldName();
        String value = item.getString();			
        try {
            //File appending
            objWriter.write(fieldName + " :  " + value);
            objWriter.write(System.getProperty( "line.separator" ));
        } 
        catch (Exception e) {
            e.printStackTrace();
        }			
    } 
    // Process a file upload
    else {
        if(_fields.equals("FieldsTrue:")){
            objWriter.flush();
            objWriter.close();	
        }
        else{
            objWriter.flush();
            objWriter.close();
            _fieldsTXT.delete();
        }
        String fieldName = item.getFieldName();
        fileName = item.getName();
        String contentType = item.getContentType();
        boolean isInMemory = item.isInMemory();
        sizeInBytes = item.getSize();
        if(fileName!=null && sizeInBytes!=0){
            String _temp_Name2 = application.getRealPath("/Dynamsoft_Upload/" + fileName);
            File uploadedFile = new File(_temp_Name2);
            if(!uploadedFile.exists())
            {
                boolean result = uploadedFile.createNewFile();
                System.out.println("File create result:"+result);
            }			
            try {
                item.write(uploadedFile);
            } 
            catch (Exception e) {
                e.printStackTrace();
            }
            if(_fieldsTXT.exists())
            {
                String _temp_Name3 = application.getRealPath("/action/Dynamsoft_Upload/" + fileName.substring(0,fileName.length()-4) + "_1.txt");
                _fieldsTXT.renameTo(new File(_temp_Name3));
            }
        }
    }
}

Save to Oracle

The following packages are required

<%@  page language="java" import="java.sql.*,java.io.*,java.util.*,org.apache.commons.fileupload.*,org.apache.commons.fileupload.disk.*,org.apache.commons.fileupload.servlet.*"%>

The code to save the file to Oracle

// Prepare credentials for connectiong to Oracle, here we use Oracle express (XE)
String strDBUser = "dwtDB"; //database,schema name as well
String strDBPassword = "NotRealPWD";
String strDriverName = "oracle.jdbc.driver.OracleDriver";
String strConnString = "jdbc:oracle:thin:@127.0.0.1:1521:XE";
Connection conn=null;
// Test Database Connection
try
{
    Class.forName(strDriverName).newInstance();
    conn = DriverManager.getConnection(strConnString, strDBUser, strDBPassword);
    conn.setAutoCommit(true);
}
catch(Exception e)
{
    out.println("An exception occurred: " + e.getMessage());
}
String fileName = "";
long sizeInBytes = 0;
// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
// Configure a repository (to ensure a secure temp location is used)
ServletContext servletContext = this.getServletConfig().getServletContext();
File repository = (File) servletContext.getAttribute("javax.servlet.context.tempdir");
// Set factory constraints
factory.setRepository(repository);
// Sets the size threshold beyond which files are written directly to disk.
factory.setSizeThreshold(1000000000);
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// Set overall request size constraint
upload.setSizeMax(-1);
// Parse the request
List<FileItem> items = upload.parseRequest(request);
// Process the uploaded items
Iterator<FileItem> iter = items.iterator();
while (iter.hasNext()) {
    try{
        FileItem item = iter.next();				
        // Process a regular form field
        if (item.isFormField()) {} 			
        // Process a file upload
        else {
            fileName = item.getName();
            sizeInBytes = item.getSize();
            if(fileName != null && sizeInBytes != 0){
                /**
                 * Get the input stream (the file)
                 */ 
                InputStream stream_Input = item.getInputStream();
                byte[] buff = new byte[8000];
                int bytesRead = 0;
                ByteArrayOutputStream stream_BAO = new ByteArrayOutputStream();
                while((bytesRead = stream_Input.read(buff)) != -1) {
                    stream_BAO.write(buff, 0, bytesRead);
                }
                byte[] data = stream_BAO.toByteArray();
                ByteArrayInputStream stream_BAI = new ByteArrayInputStream(data);
                stream_Input.close();
                /**
                 * Save the stream into Oracle
                 */ 
                PreparedStatement preparedStatement = conn.prepareStatement("insert into dwtsample(id, document_name, document_data) values(s_tblImage.NextVal, ?, ?)");
                preparedStatement.setString(1, fileName);
                preparedStatement.setBinaryStream(2, stream_BAI, stream_BAI.available());
                preparedStatement.executeUpdate();
                preparedStatement.close();
                conn.close();
            }
        }
    }
    catch(Exception e) 
    { 	
    }
}

Upload via ColdFusion

<cfset uploadFolderPath=GetDirectoryFromPath(GetCurrentTemplatePath()) />
<cfset newFolder=uploadFolderPath & "\Dynamsoft_Upload\" />
<cffile action="upload" filefield="RemoteFile" destination="#newFolder#" nameconflict="OVERWRITE" />

Upload to Node Express Server

var formidable = require('formidable');
var util = require('util');
var express = require('express');
var fs = require('fs');
var app = express();
app.use(express.static(__dirname));
app.use(function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", "PUT, POST, GET, DELETE, OPTIONS");
    res.header("Access-Control-Allow-Headers", "*");
    res.header("Access-Control-Allow-Credentials", true);
    next();
});
app.post('/upload', function(req, res) {
    var form = new formidable.IncomingForm();
    form.parse(req, function(err, fields, files) {
        fs.readFile(files.RemoteFile.path, function(err, data) {
            // save file from temp dir to new dir
            var newPath = __dirname + "/uploaded/" + files.RemoteFile.name;
            fs.writeFile(newPath, data, function(err) {
                if (err) throw err;
                console.log('file saved');
                res.end();
            });
        });
    });
})
var server = app.listen(2020, function() {
    var host = server.address().address;
    var port = server.address().port;
    console.log('listening at http://%s:%s', host, port);
})

Upload via MVC Controller

[HttpPost]
public Boolean Upload()
{
    HttpFileCollectionBase files = HttpContext.Request.Files;
    HttpPostedFileBase uploadfile = files.Get("RemoteFile");
    var uploads = Path.Combine(HostingEnvironment.ApplicationPhysicalPath,"UploadedImages");
    if (!Directory.Exists(uploads))
    {
        Directory.CreateDirectory(uploads);
    }
    Boolean fileUploaded = false;
    for (var i = 0; i < files.Count; i++)
    {
        var file = files[i];
        if (file.ContentLength > 0)
        {
            var filePath = Path.Combine(uploads, file.FileName);
            file.SaveAs(filePath);
            fileUploaded = true;
        }
    }
    return fileUploaded;
}

Upload to Azure

DateTime utc = DateTime.Now.ToUniversalTime();
// (1) Prepare your data
String accountName = "dynamsoft";
String accountKey = "";
String baseUrl = "http://dynamsoft.blob.core.windows.net/dwt/";
String resourceName = Request["imageName"];
String path = "/dwt";
DateTime utc_start = utc.AddSeconds(-10); // 10 seconds before
String start = utc_start.GetDateTimeFormats('s')[0].ToString() + ".0000000Z";
DateTime utc_expires = utc.AddSeconds(1200);// 20 miniteus later
String expires = utc_expires.GetDateTimeFormats('s')[0].ToString() + ".0000000Z";
// (2) generate signature
String strToSign1 = "w";
String strToSign2 = start;
String strToSign3 = expires;
String strToSign4 = "/" + accountName + path;
String strToSign5 = "";
String strSign = String.Format("{0}\n{1}\n{2}\n{3}\n{4}", strToSign1, strToSign2, strToSign3, strToSign4, strToSign5);
// decoding
byte[] tobedecodedbytes = System.Convert.FromBase64String(accountKey);
System.Security.Cryptography.HMACSHA256 hmac = new System.Security.Cryptography.HMACSHA256(tobedecodedbytes);
hmac.Initialize();
byte[] buffer = Encoding.UTF8.GetBytes(strSign);
byte[] arrMAC = hmac.ComputeHash(buffer);
String strSig = System.Convert.ToBase64String(arrMAC);
// (3) generate SAS the query 
start = Server.UrlEncode(start);
expires = Server.UrlEncode(expires);
strSig = Server.UrlEncode(strSig);
String strParams = String.Format("sp=w&st={0}&se={1}&sr=c&sig={2}", start, expires, strSig);
String url = baseUrl + resourceName + "?" + strParams;
Response.Write(url);

Resend the uploaded file by email

The following code uses ASP. NET (CSharp)

  • Configure the server (Gmail as an example)
‹system.net›
‹mailSettings›
    ‹smtp from="***@gmail.com"›
        ‹network host="smtp.gmail.com" port="25" userName="***@gmail.com" password="***" enableSsl="true"/›
    ‹/smtp›
‹/mailSettings›
‹/system.net›
  • Make use of the System.Net.Mail namespace
using System.Net.Mail;
  • Add code to email the file as an attachment
HttpFileCollection files = HttpContext.Current.Request.Files;
HttpPostedFile uploadfile = files["RemoteFile"];
SmtpClient client = new SmtpClient();
MailAddress from = new MailAddress("***@gmail.com", " Test", System.Text.Encoding.UTF8);
MailAddress to = new MailAddress("***@gmail.com");
MailMessage message = new MailMessage(from, to);
message.Body = "This is a test email sent by ASP.NET";
message.BodyEncoding = System.Text.Encoding.UTF8;
message.Subject = "Just Testing";
message.SubjectEncoding = System.Text.Encoding.UTF8;
// Create the file attachment
Attachment data = new Attachment(uploadfile.InputStream, uploadfile.FileName);
message.Attachments.Add(data);
client.Send(message);
data.Dispose();

Download a file

The following scripts are used for downloading from a URL which points to a server-side script

Download via CSharp

Get a file on the disk

String fileName = "sample.tif";
String filePath = Server.MapPath(".") + "\\files\\" + fileName;
System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
Response.ClearContent();
Response.ClearHeaders();
Response.Clear();
Response.Buffer = true;
String fileNameEncode;
fileNameEncode = HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8);
fileNameEncode = fileNameEncode.Replace("+", "%20");
String appendedheader = "attachment;filename=" + fileNameEncode;
Response.AppendHeader("Content-Disposition", appendedheader);
Response.WriteFile(fileInfo.FullName);

Get a file from MS SQL

Check out Save to MS SQL for code on making the connection to the SQL.

// ...Code to connect to MS SQL
// `strImageID` specify the file to download
String sql_getData = "SELECT * FROM " + tableName + " WHERE id = " + strImageID;
using (System.Data.SqlClient.SqlCommand sqlcmd_getData = new System.Data.SqlClient.SqlCommand(sql_getData, Connection))
{
    System.Data.SqlClient.SqlDataReader sdrRecordset = sqlcmd_getData.ExecuteReader();
    sdrRecordset.Read();
    String imgName = sdrRecordset["document_name"].ToString();
    String imgNameExtension = imgName.Substring(imgName.LastIndexOf("."));
    // Reads the file data as byte array
    byte[] byFileData = (byte[])sdrRecordset["document_data"];
    sdrRecordset.Close();
    Connection.Close();
    sdrRecordset = null;
    Response.Clear();
    Response.Buffer = true;
    switch(imgNameExtension)
    {
        // Sets the correct content type
        case "bmp": Response.ContentType = "image/bmp"; break;
        case "jpg": Response.ContentType = "image/jpg"; break;
        case "tif": Response.ContentType = "image/tiff"; break;
        case "png": Response.ContentType = "image/png"; break;
        case "pdf": Response.ContentType = "application/pdf"; break;
        default: break;
    }
    try
    {
        // Write the file back
        String fileNameEncode;
        fileNameEncode = HttpUtility.UrlEncode(imgName, System.Text.Encoding.UTF8);
        fileNameEncode = fileNameEncode.Replace("+", "%20");
        String appendedheader = "attachment;filename=" + fileNameEncode;
        Response.AppendHeader("Content-Disposition", appendedheader);
        Response.OutputStream.Write(byFileData, 0, byFileData.Length);
    }
    catch (Exception exc)
    {}
    Response.Flush();
    Response.Close();
}

Download via PHP

Get a file out of MySQL

Check out Save to MySQL for code on making the connection to MySQL.

// ...Code to connect to MySQL
// `$strImageID` specify the file to download
$sql_getData = "SELECT * FROM ".$tablename." WHERE id = ".$strImageID;
$result = $conn->query($sql_getData);
if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        $documentName = $row["document_name"];
        $strImageExtName = substr($documentName, strlen($documentName) - 3);
        $documentData = $row["document_data"];
    }
}
$conn->close();
//Begin writing headers
header("Content-Description: File Transfer");
$header="Content-Disposition: attachment; filename=".$documentName.";";
header($header);
header("Content-Transfer-Encoding: binary");
// Sets the correct content type
if($strImageExtName == "bmp"){
    header('Content-Type: image/bmp');
}else if($strImageExtName == "jpg"){
    header('Content-Type: image/jpg');
}else if($strImageExtName == "tif"){
    header('Content-Type: image/tiff');
}else if($strImageExtName == "png"){
    header('Content-Type: image/png');
}else if($strImageExtName == "pdf"){
    header('Content-Type: application/pdf');
}
// Write the file back
echo $documentData;

Download via JSP

Get a file out of Oracle

Check out Save to Oracle for code on making the connection to MySQL.

// ...Code to connect to Oracle
// `strImageID` specify the file to download
Statement sql_getData = conn.createStatement(); 
ResultSet res_getData = sql_getData.executeQuery("select * from dwtsample where id =" + strImageID);

String documentName = "";
String strImageExtName = "";
String strImg="";

if (res_getData.next()){
    documentName = res_getData.getString("document_name");
    strImageExtName = documentName.substring(documentName.lastIndexOf(".") + 1);	
    Blob blob = res_getData.getBlob("document_data");
    InputStream steam_Input = blob.getBinaryStream();
    if (steam_Input != null) {
        // Gets the file as a byte array
        BufferedInputStream stream_BufferInput = new BufferedInputStream(steam_Input);
        byte[] byte_buf = new byte[(int)blob.length()];
        stream_BufferInput.read(byte_buf);
        stream_BufferInput.close();
        conn.close();

        response.setHeader("Content-disposition", "attachment; filename=\"" + documentName + "\"");
        response.setHeader("Content-Length", String.valueOf(byte_buf.length));
        // Sets the correct content type
        if(strImageExtName == "bmp"){
            response.setContentType("image/bmp");
        }else if(strImageExtName == "jpg"){
            response.setContentType("image/jpg");
        }else if(strImageExtName == "tif"){
            response.setContentType("image/tiff");
        }else if(strImageExtName == "png"){
            response.setContentType("image/png");
        }else if(strImageExtName == "pdf"){
            response.setContentType("application/pdf");
        }
        // Write the file back
        OutputStream stream_Output = response.getOutputStream();
        stream_Output.write(byte_buf, 0, byte_buf.length);
        stream_Output.flush();
        stream_Output.close();
    }
    else {
        out.println("<script language='javascript'>");
        out.println("alert('No image found!');");
        out.println("</script>");
    }
}

Other Scripts

License Checker for OCRPro

When performing a client-side OCR operation with OCRPro , the engine sends HTTP POST requests to the server for license tracking. The following code snippet shows how the requests are redirected to the class LicenseCheckerServer .

The class LicenseCheckerServer is defined in the files CheckLicense.dll and LicenseReader.dll . If you don’t have these files in your application, you can contact Dynamsoft Support or download them from here.

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text;
using System.Drawing;
using CheckLicense;

namespace Dynamsoft
{
    public partial class LicenseChecker : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (this.Request.Form["DTW_AjaxMethod"] != null)
            {
                String strMethod = this.Request.Form["DTW_AjaxMethod"];
                if (strMethod == "CheckLicense")
                {
                    Response.Write(LicenseCheckerServer.CheckLicense(this.Request.Form["Productkey"], HttpContext.Current.Server.MapPath("OCRPro.lic")));
                }
                else if (strMethod == "WriteOCRCount")
                {
                    Response.Write(LicenseCheckerServer.WriteOCRCount(this.Request.Form["OCRCount"], HttpContext.Current.Server.MapPath("OCRPro.lic")));
                }
            }
            else
            {
                Response.Write(LicenseCheckerServer.GetErrorString());
            }
        }
    }
}

Is this page helpful?

YesYes NoNo

In this article:

latest version

    • Latest Version
    • Version 16.1.1
    Change +
    © 2003–2020 Dynamsoft. All rights reserved.
    Privacy Statement / Site Map / Home / Purchase / Support