Password protected excel as mail attachment - java

I have created a jar for sending mail using java. I have to attach an excel file with mail. Am using HSSF for creating worksheet. But I need to encrypt the attachment with password. I succeeded. But when I open the attachment directly from mail through Outlook it's not asking password. and when I copy to any folder and then if I try to open , it works properly. Can anyone, please help?
public static void main(final String... args) throws Exception {
String fname = "D:\\Mail\\Sample.xls";
FileInputStream fileInput = null;
BufferedInputStream bufferInput = null;
POIFSFileSystem poiFileSystem = null;
FileOutputStream fileOut = null;
try {
fileInput = new FileInputStream(fname);
bufferInput = new BufferedInputStream(fileInput);
poiFileSystem = new POIFSFileSystem(bufferInput);
Biff8EncryptionKey.setCurrentUserPassword("secret");
HSSFWorkbook workbook = new HSSFWorkbook(poiFileSystem, true);
HSSFSheet sheet = workbook.getSheetAt(0);
HSSFRow row = sheet.createRow(0);
Cell cell = row.createCell(0);
cell.setCellValue("THIS WORKS!");
fileOut = new FileOutputStream(fname);
workbook.writeProtectWorkbook(Biff8EncryptionKey.getCurrentUserPassword(), "");
workbook.write(fileOut);
File file = new File("D:\\Mail\\Sample.xls");
FileInputStream fis = new FileInputStream(file);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
try {
for (int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum);
System.out.println("read " + readNum + " bytes,");
}
} catch (IOException ex) {
}
byte[] bytes = bos.toByteArray();
// Code for sending mail
} catch (Exception ex) {
System.out.println(ex.getMessage());
} finally {
try {
bufferInput.close();
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
try {
fileOut.close();
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
}
}

Method HSSFWorkbook.writeProtectWorkbook(...) is only meant to protect the workbook from being written to / modified.
If you try to open it in read+write mode (default in Windows folders), it will ask you for the password.
But if you open it in read-only mode, which is what Outlook does with attachments, it will let you view the contents since you can't write over them and thus you don't need the write password.
That's the reason you can view (but not edit) it in Outlook but not when you open it from a folder.
I don't know if the latest version of Apache POI supports full password protection for an HSSFWorkBook (a quick Google search says it doesn't, but who knows).
If it doesn't, you can work around this problem by making a password-protected ZIP file with the excel in it, and attaching the ZIP file instead.

Related

How to write to file without actually creating it on the server

The below code works fine on my local machine. But it does not work on the server - maybe because of permissions.
Can I make this work without actually creating a file on the server?
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.createSheet(Constants.SHEET_NAME);
for (Integer serialNo : reportReq.getSerialNos()) {
TraitsExceptionReport report = traitsExceptionReport.get(serialNo - 1);
Row row = sheet.createRow(rownum++);
createList(report, row);
}
File file = new File(Constants.TMP_FILE_NAME);
String absolutePath = file.getAbsolutePath();
FileOutputStream out = new FileOutputStream(file);
workbook.write(out);
FileInputStream fis = new FileInputStream(absolutePath );
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
out.close();
try {
for (int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum);
}
} catch (IOException ex) {
throw new IOException("Exception while creating Traits Exception Report");
}
fis.close();
Files.deleteIfExists(Paths.get(absolutePath));
return(bos.toByteArray());
What is the standard way followed when developers will have to write a file on the unix servers.
POI 5.0.0 added a DeferredSXSSFWorkbook - works a bit like SXSSFWorkbook but doesn't need temp files - it uses a row generating function for each sheet that is executed lazily when you write out the workbook to an output stream.
I just added a simplistic sample to https://github.com/apache/poi/blob/trunk/src/examples/src/org/apache/poi/examples/xssf/streaming/DeferredGeneration.java
There are some tests and you might get the gist of how it works from
https://github.com/apache/poi/blob/trunk/src/ooxml/testcases/org/apache/poi/xssf/streaming/TestDeferredSXSSFWorkbook.java

How to create a ZIP InputStream in Android without creating a ZIP file first?

I use NanoHTTPD as web server in my Android APP, I hope to compress some files and create a InputStream in server side, and I download the InputStream in client side using Code A.
I have read Code B at How to zip and unzip the files?, but how to create a ZIP InputStream in Android without creating a ZIP file first?
BTW, I don't think Code C is good way, because it make ZIP file first, then convert ZIP file to FileInputStream , I hope to create a ZIP InputStream directly!
Code A
private Response ActionDownloadSingleFile(InputStream fis) {
Response response = null;
response = newChunkedResponse(Response.Status.OK, "application/octet-stream",fis);
response.addHeader("Content-Disposition", "attachment; filename="+"my.zip");
return response;
}
Code B
public static void zip(String[] files, String zipFile) throws IOException {
BufferedInputStream origin = null;
ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(zipFile)));
try {
byte data[] = new byte[BUFFER_SIZE];
for (int i = 0; i < files.length; i++) {
FileInputStream fi = new FileInputStream(files[i]);
origin = new BufferedInputStream(fi, BUFFER_SIZE);
try {
ZipEntry entry = new ZipEntry(files[i].substring(files[i].lastIndexOf("/") + 1));
out.putNextEntry(entry);
int count;
while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1) {
out.write(data, 0, count);
}
}
finally {
origin.close();
}
}
}
finally {
out.close();
}
}
Code C
File file= new File("my.zip");
FileInputStream fis = null;
try
{
fis = new FileInputStream(file);
} catch (FileNotFoundException ex)
{
}
ZipInputStream as per the documentation ZipInputStream
ZipInputStream is an input stream filter for reading files in the ZIP file format. Includes support for both compressed and uncompressed entries.
Earlier I answered to this question in a way that it is not possible using ZipInputStream. I am Sorry.
But after investing some time I found that it is possible as per the below code
It is very much obvious that since you are sending files in zip format
over the network.
//Create proper background thread pool. Not best but just for solution
new Thread(new Runnable() {
#Override
public void run() {
// Moves the current Thread into the background
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_BACKGROUND);
HttpURLConnection httpURLConnection = null;
byte[] buffer = new byte[2048];
try {
//Your http connection
httpURLConnection = (HttpURLConnection) new URL("https://s3-ap-southeast-1.amazonaws.com/uploads-ap.hipchat.com/107225/1251522/SFSCjI8ZRB7FjV9/zvsd.zip").openConnection();
//Change below path to Environment.getExternalStorageDirectory() or something of your
// own by creating storage utils
File outputFilePath = new File ("/mnt/sdcard/Android/data/somedirectory/");
ZipInputStream zipInputStream = new ZipInputStream(new BufferedInputStream(httpURLConnection.getInputStream()));
ZipEntry zipEntry = zipInputStream.getNextEntry();
int readLength;
while(zipEntry != null){
File newFile = new File(outputFilePath, zipEntry.getName());
if (!zipEntry.isDirectory()) {
FileOutputStream fos = new FileOutputStream(newFile);
while ((readLength = zipInputStream.read(buffer)) > 0) {
fos.write(buffer, 0, readLength);
}
fos.close();
} else {
newFile.mkdirs();
}
Log.i("zip file path = ", newFile.getPath());
zipInputStream.closeEntry();
zipEntry = zipInputStream.getNextEntry();
}
// Close Stream and disconnect HTTP connection. Move to finally
zipInputStream.closeEntry();
zipInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}finally {
// Close Stream and disconnect HTTP connection.
if (httpURLConnection != null) {
httpURLConnection.disconnect();
}
}
}
}).start();

Saving a spreadsheet to disk using java

I have a requirement to store the uploaded spreadsheet to the disk. I am using the below code to do the same and receiving the file is corrupted error from the excel.
byte[] bytes = null;
File uploadedFile = new File("D://xlsxTest//BNG Issue.xlsx");
File file = new File("D://xlsxTest//sample1.xlsx");
FileOutputStream outStream = null;
InputStream inputStream = null;
try{
if(!file.exists()){
file.createNewFile();
}
outStream = new FileOutputStream(file);
if (uploadedFile != null) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
inputStream = new FileInputStream(uploadedFile);;
int c = 0;
while (c != -1) {
c = inputStream.read();
byteArrayOutputStream.write((char) c);
}
bytes = byteArrayOutputStream.toByteArray();
}
outStream.write(bytes);
}catch(Exception e){
e.printStackTrace();
}finally{
try{
outStream.close();
}catch(Exception e){
e.printStackTrace();
}
}
I tried using a file of 83KB size and the resultant file is 82.5KB.
Any help would be appreciated.
Thanks.
Try using Apace POI, Convert .xls or .xlsx file to byte array using OPCPackage and XSSFWorkbook with below code.
ByteArrayOutputStream baos = new ByteArrayOutputStream();
OPCPackage pkg = OPCPackage.open(new File(fullFileName));
XSSFWorkbook wb = new XSSFWorkbook(pkg);
wb.write(baos);
byte[] fileContent = baos.toByteArray();
Apache POI takes care to extract all information of the excel file while converting to byte array.

Writing decoded base64 byte array as image file

String base64Code = dataInputStream.readUTF();
byte[] decodedString = null;
decodedString = Base64.decodeBase64(base64Code);
FileOutputStream imageOutFile = new FileOutputStream(
"E:/water-drop-after-convert.jpg");
imageOutFile.write(decodedString);
imageOutFile.close();
The problem is the data is transferred completely and if the data is in text format it is displayed correctly however when i am trying to decode image and write it on output file,it doesnt simply show up in photo viewer.
Any help would be highly appreciated
DataInputStream.readUTF may be the issue. This method assumes that the text was written to the file by DataOutputStream.writeUTF. If it is not so, and you are going to read a regular text, choose a different class, like BufferedReader or Scanner. Or Java 1.7's Files.readAllBytes.
Once I had to convert the Image into base 64 and sent that image as stream (encoding and decoding stuff here is the code)
To Convert a file into base64 :
String filePath = "E:\\water-drop-after-convert.jpg";
File bMap = new File(filePath);
byte[] bFile = new byte[(int) bMap.length()];
FileInputStream fileInputStream = null;
String imageFileBase64 = null;
try {
fileInputStream = new FileInputStream(bMap);
fileInputStream.read(bFile);
fileInputStream.close();
imageFileBase64 = Base64.encode(bFile);
}catch(Exception e){
e.printStackTrace();
}
then on service side I did thing like that to convert image in base 64 String back into file, so that i can display.
I had used this library on server side import sun.misc.BASE64Decoder;
//filePath is where you wana save image
String filePath = "E:\\water-drop-after-convert.jpg";
File imageFile = new File(filePath);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(imageFile);
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
BASE64Decoder decoder = new BASE64Decoder();
byte[] decodedBytes = null;
try {
decodedBytes = decoder.decodeBuffer(imageFileBase64);//taking input string i.e the image contents in base 64
} catch (IOException e1) {
e1.printStackTrace();
}
try {
fos.write(decodedBytes);
} catch (IOException e) {
e.printStackTrace();
}
try {
fos.flush();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}

Java: Need to create PDF from byte-Array

From a DB2 table I've got blob which I'm converting to a byte array so I can work with it. I need to take the byte array and create a PDF out of it.
This is what I have:
static void byteArrayToFile(byte[] bArray) {
try {
// Create file
FileWriter fstream = new FileWriter("out.pdf");
BufferedWriter out = new BufferedWriter(fstream);
for (Byte b: bArray) {
out.write(b);
}
out.close();
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
}
But the PDF it creates is not right, it has a bunch of black lines running from top to bottom on it.
I was actually able to create the correct PDF by writing a web application using essentially the same process. The primary difference between the web application and the code about was this line:
response.setContentType("application/pdf");
So I know the byte array is a PDF and it can be done, but my code in byteArrayToFile won't create a clean PDF.
Any ideas on how I can make it work?
Sending your output through a FileWriter is corrupting it because the data is bytes, and FileWriters are for writing characters. All you need is:
OutputStream out = new FileOutputStream("out.pdf");
out.write(bArray);
out.close();
One can utilize the autoclosable interface that was introduced in java 7.
try (OutputStream out = new FileOutputStream("out.pdf")) {
out.write(bArray);
}
Read from file or string to bytearray.
byte[] filedata = null;
String content = new String(bytearray);
content = content.replace("\r", "").replace("\uf8ff", "").replace("'", "").replace("\"", "").replace("`", "");
String[] arrOfStr = content.split("\n");
PDDocument document = new PDDocument();
PDPage page = new PDPage();
document.addPage(page);
try (PDPageContentStream cs = new PDPageContentStream(document, page)) {
// setting font family and font size
cs.beginText();
cs.setFont(PDType1Font.HELVETICA, 14);
cs.setNonStrokingColor(Color.BLACK);
cs.newLineAtOffset(20, 750);
for (String str: arrOfStr) {
cs.newLineAtOffset(0, -15);
cs.showText(str);
}
cs.newLine();
cs.endText();
}
document.save(znaFile);
document.close();
public static String getPDF() throws IOException {
File file = new File("give complete path of file which must be read");
FileInputStream stream = new FileInputStream(file);
byte[] buffer = new byte[8192];
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int bytesRead;enter code here
while ((bytesRead = stream.read(buffer)) != -1) {
baos.write(buffer, 0, bytesRead);
}
System.out.println("it came back"+baos);
byte[] buffer1= baos.toByteArray();
String fileName = "give your filename with location";
//stream.close();
FileOutputStream outputStream =
new FileOutputStream(fileName);
outputStream.write(buffer1);
return fileName;
}

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