dextuploadjk.support.common
Class FileDownload

Minimum version

1.0.0

Minimum environment

Java 17

Description

FileDownload is a class that provides the ability to download data from physical files and memory to a file format.

The FileDownload class is used in a Servlet/JSP environment.

# Downloading from a file

FileDownload downloader = new FileDownload();

// Set options
FileDownloadOption option = new FileDownloadOption();
option.setFilename("sea.png");

// Download from a file
downloader.download(request, response, file, option);

# Download from data (stream download)

FileDownload downloader = new FileDownload();

// Set options
FileDownloadOption option = new FileDownloadOption();
option.setFilename("profile.txt");

// Download from an input stream
downloader.download(request, response, inputStream, option);

Constructor

Create an object of class FileDownload.
Signatures
```
public FileDownload()
```

Methods

isAllowingWeakRange

Returns whether to perform a partial content download using only the Range request header.

(A partial content download is one that returns only a portion of the data as response data.)
Signatures
```
public boolean isAllowingWeakRange()
```
Return

true, false

setAllowingWeakRange

Sets whether to perform a Partial Content download with only the Range request header.

(A partial content download is one that returns only a portion of the data as response data.)

Signatures

public void setAllowingWeakRange(boolean allowingWeakRange)

Parameters

Name	Type	Description
allowingWeakRange	boolean	If true, only the Range header is processed; if false, the If-Range header is checked.

isRemoveAfterDownloading

Returns whether to delete the target file after downloading the file.

Signatures

public boolean isRemoveAfterDownloading()

Return

true, false

setRemoveAfterDownloading

Sets whether to delete the target file after downloading the file.

Deleting the file will only work if the entire file is downloaded as an attachment, and deleting the file may fail if the target file is preempted by another system.

Signatures

public void setRemoveAfterDownloading(boolean removeAfterDownloading)

Parameters

Name	Type	Description
removeAfterDownloading	boolean	Set to true to delete the file.

isAutoClosingStream

Returns whether to automatically close the InputStream object after the download is complete.
Signatures
```
public boolean isAutoClosingStream()
```
Return

true, false

setAutoClosingStream

Sets whether to automatically close the InputStream object when downloading.

Only affects when the InputStream is fed data to be downloaded.

Signatures

public void setAutoClosingStream(boolean autoClosingStream)

Parameters

Name	Type	Description
autoClosingStream	boolean	If the parameter value is set to true, the InputStream object is closed after writing the data to the response buffer.

getExpiringTime

Returns the time value required to set the cache expiration response header.
Signatures
```
public long getExpiringTime()
```
Return

Time value in seconds to set the cache expired response header

setExpiringTime

Sets the time value required to set the cache expired response header.
Signatures
```
public void setExpiringTime(long time)
```

Parameters

Name	Type	Description
time	long	Setting value in seconds

getUseTomcatSendFile (supported from version 1.2.0)

Returns whether Tomcat sendFile is used for file downloads.
Signatures
```
public boolean getUseTomcatSendFile()
```
Return

true or false. The default value is false.

setUseTomcatSendFile (supported from version 1.2.0)

Sets whether Tomcat sendFile is used for file downloads.

(Caution) This setting cannot be used when HTTP compression is enabled or when response data is controlled through a servlet filter. If an error occurs, set this value to false to use the default download method.

Signatures

public void setUseTomcatSendFile(boolean useTomatSendFile)

Parameters

Name	Type	Description
useTomatSendFile	boolean	true to use sendFile; otherwise false

download

Download a physical file or data in memory.

It is recommended to use the download method with the FileDownloadOption parameter.

Signatures

public void download(HttpServletRequest request, HttpServletResponse response, InputStream targetSteam, String filename, String mime, boolean inline)
public void download(HttpServletRequest request, HttpServletResponse response, InputStream targetSteam, String filename, String mime)
public void download(HttpServletRequest request, HttpServletResponse response, InputStream targetSteam, String filename)
public void download(HttpServletRequest request, HttpServletResponse response, File target, String filename, String mime, boolean inline, boolean useClientCache)
public void download(HttpServletRequest request, HttpServletResponse response, File target, String filename, String mime, boolean inline)
public void download(HttpServletRequest request, HttpServletResponse response, File target, String filename, String mime)
public void download(HttpServletRequest request, HttpServletResponse response, File target, String filename)
public void download(HttpServletRequest request, HttpServletResponse response, File target)
public void download(HttpServletRequest request, HttpServletResponse response, InputStream target, FileDownloadOption option)
public void download(HttpServletRequest request, HttpServletResponse response, File target, FileDownloadOption option)

Parameters

Name	Type	Description
request	javax.servlet.http.HttpServletRequest	HttpServletRequest object
response	javax.servlet.http.HttpServletResponse	HttpServletResponse object
target	java.io.File	The File object to be downloaded
targetSteam	java.io.InputStream	The InputStream object to be downloaded
filename	java.lang.String	The file name to download
mime	java.lang.String	Sets the MIME type of the file to be downloaded. If you don't know the MIME-TYPE of the target, you should set it to something like 'application/octet-stream'.
inline	boolean	If you set the parameter value to true, the file will not be downloaded and may be opened directly in the browser.
useClientCache	boolean	Set whether to use the client cache policy.
option	dextuploadjk.engine.FileDownloadOption	An object with the option information needed to download the file.

Exception: IOException

Uses

# Downloading from a file
FileDownload fileDownload = new FileDownload();
FileDownloadOption option = new FileDownloadOption();
option.setFilename("manual.docx");
option.setMime("appliation/octet-stream");
fileDownload.download(request, response, new File("/data/F20220720-0001.docx"), option);

# Download from data
InputStream is = null;
try {
    is = new ByteArrayInputStream(...);
  
    FileDownload fileDownload = new FileDownload();
    FileDownloadOption option = new FileDownloadOption();
    option.setFilename("manual.docx");
    option.setMime("appliation/octet-stream");
    fileDownload.download(request, response, is, option);
} catch (Exception e) {
    ...
} finally {
    if (is != null) is.close();
}

downloadZip

Compresses the given file or directory into a zip file and downloads it immediately.

The compressed file is removed internally as soon as the download is complete, and compressed downloads do not support partial content downloads.

Signatures

public void downloadZip(HttpServletRequest request, HttpServletResponse response, String filename, List<File> targets, File tempZipDir, String encoding, boolean includeHiddenFile)
public void downloadZip(HttpServletRequest request, HttpServletResponse response, String filename, List<File> targets, List<String> names, File tempZipDir, String encoding, boolean includeHiddenFile)
public void downloadZip(HttpServletRequest request, HttpServletResponse response, String filename, File targetDir, boolean includeTargetDirName, File tempZipDir, String encoding, boolean includeHiddenFile)

Parameters

Name	Type	Description
request	javax.servlet.http.HttpServletRequest	HttpServletRequest object
response	javax.servlet.http.HttpServletResponse	HttpServletResponse object
filename	java.lang.String	Sets the filename to download. If null, the compressed filename is used.
targets	java.util.List<File>	An object pointing to a list of files to compress.
targetDir	File	An object pointing to the directory to compress.
includeTargetDirName	boolean	Sets whether to include the root directory when compressing. If true, compresses the target directory, and if false, compresses child files or child directories without the target.
tempZipDir	File	An object pointing to a temporary directory where the zip file will be created. If null, the operating system determines the location of the temporary directory.
encoding	java.lang.String	Sets the charset name to use when encoding filenames containing multiple languages. Typically set to "UTF-8"; if null, use the charset set in the response object.
includeHiddenFile	boolean	Sets whether to compress hidden files when compressing.
names	java.util.List<java.lang.String>	A list of file names to compress, which should be the same size as the targets parameter.

Uses

List<File> files = new ArrayList<File>();
files.add(new File("/src/test/resources/compress/....txt"));
files.add(new File("/src/test/resources/compress/....pdf"));
files.add(new File("/src/test/resources/compress/subA/subB/....txt"));
files.add(new File("/src/test/resources/compress/....jpg"));
files.add(new File("/src/test/resources/compress/....docx"));
		
FileDownload dextnj = new FileDownload();
dextnj.downloadZip(request, response, null, files, null, null, false);

dextuploadjk.support.commonClass FileDownload

dextuploadjk.support.common
Class FileDownload