Develop Reference

Convert BLOB to PDF

I have a BLOB file which I have got from the DB team. I know that its a PDF document (I opened using Notepad++ and I could see the file name) and I need to convert the same using java. I have checked for few examples and I couldn't find any example where the BLOB file itself is taken as an input instead of taking directly from the DB (Resultset). Can anyone please give some pointers as to how I can accomplish this?
Thanks in advance!
I have tried below,
File file = new File("C:/Users/User1/Desktop/0LK54E33K1477e2MCEU25JV0G8MG418S007N45JU.BLOB0");
FileInputStream fis = new FileInputStream(file);
//System.out.println(file.exists() + "!!");
//InputStream in = resource.openStream();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
try {
for (int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum); //no doubt here is 0
//Writes len bytes from the specified byte array starting at offset off to this byte array output stream.
System.out.println("read " + readNum + " bytes,");
}
} catch (IOException ex) {
//Logger.getLogger(genJpeg.class.getName()).log(Level.SEVERE, null, ex);
}
byte[] bytes = bos.toByteArray();
//below is the different part
File someFile = new File("C:/Users/User1/Desktop/Test.pdf");
FileOutputStream fos = new FileOutputStream(someFile);
fos.write(bytes);
fos.flush();
fos.close();

Amazon Merchant Fulfilment Create Shipment Label

I am trying to get the shipment label from amazon merchant fulfillment as per the instructions mentioned on the Amazon pages.
"To obtain the actual PDF document, you must decode the Base64-encoded string, save it as a binary file with a “.zip” extension, and then extract the PDF file from the ZIP file."
Has any one got it to work. I have tried couple of things but every time i get blank pdf.
Here is my code. Can please some body guide me if I am doing it correctly
byte[] decodedBytes = Base64.decodeBase64(contents);
ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream("c:\\output\\asdwd.zip")));
//now create the entry in zip file
ZipEntry entry = new ZipEntry("asd.pdf");
zos.putNextEntry(entry);
zos.write(decodedBytes);
zos.close();

The instructions say to save the bytes as a binary file with the extension .zip.
What you are actually doing is creating a ZIP file with the contents of the byte array as an entry.
According to my reading of the instructions, your code should do this:
byte[] decodedBytes = Base64.decodeBase64(contents);
FileOutputStream fos = new FileOutputStream("c:\\output\\asdwd.zip");
fos.write(decodedBytes);
fos.close();
Or better still:
byte[] decodedBytes = Base64.decodeBase64(contents);
try (FileOutputStream fos = new FileOutputStream("c:\\output\\asdwd.zip")) {
fos.write(decodedBytes);
}
Then using a ZIP tool or a web browser, open asdwd.zip, find the entry containing the PDF, and extract it or print it.

Here is the code to generate a shipping label in case somebody needs it.
byte[] decoded = Base64.decodeBase64(contents);
try (FileOutputStream fos = new FileOutputStream(zipFilePath + amazonOrderId + zipFileName)) {
fos.write(decoded);
fos.close();
}
file = new File(destDirectory + amazonOrderId + pngFile);
if (file.exists()) {
file.delete();
}
try (OutputStream out = new FileOutputStream(destDirectory + amazonOrderId + pngFile)) {
try (InputStream in = new GZIPInputStream(
new FileInputStream(zipFilePath + amazonOrderId + zipFileName))) {
byte[] buffer = new byte[65536];
int noRead;
while ((noRead = in.read(buffer)) != -1) {
out.write(buffer, 0, noRead);
}
}
}

How to get Java Resource file into byte[]?

I have a Java program that needs to read a file from a resource within the JAR and it only takes it through byte[]. My problem is converting the resource file from a folder within the project (i.e. tools/test.txt) into byte[]. I have tried the following (gave an "undefined for type" error):
final byte[] temp = new File("tools/test.txt").getBytes();
Another method I tried resulted in not being able to find the file:
FileOutputStream fos = new FileOutputStream("tools/test.txt");
byte[] myByteArray = null;
fos.write(myByteArray);
fos.close();
System.out.println("Results = " + myByteArray);
And lastly using Inputstream and BufferedReader. This actually gave the content of the file when running the program from Eclipse, but came out as null when running it as a jar (I am assuming that it is also not reading the file).
InputStream is = null;
BufferedReader br = null;
String line;
ArrayList list = new ArrayList();
try {
is = Main.class.getResourceAsStream("tools/test.txt");
br = new BufferedReader(new InputStreamReader(is));
while (null != (line = br.readLine())) {
list.add(line);
System.out.println("Output:" + line);
}
while (null == (line = br.readLine())) {
System.out.println("Error loading file:" + line);
}
}
catch (Exception ef) {
ef.printStackTrace();
System.out.println("Output:" + ef);
}
So my question is, if I have a folder named "tools" and have a file called "test.txt", what code would I use to turn it into byte[] and still work when compiled into a Jar file?

ByteArrayOutputStream baos = new ByteArrayOutputStream();
InputStream in = Main.class.getResourceAsStream("/tools/test.txt");
byte[] buffer = new byte[4096];
for (;;) {
int nread = in.read(buffer);
if (nread <= 0) {
break;
}
baos.write(buffer, 0, nread);
}
byte[] data = baos.toByteArray();
String text = new String(data, "Windows-1252");
Byte[] asByteObjects = new Byte[data.length];
for (int i # 0; i < data.length: ++i) {
asByteObjects[i] = data[i];
}
Without the heading slash the path would be relative to the package of the class. A ByteArrayOutputStream serves to collect for a byte[].
If the bytes represent text is some encoding, one can turn it into a String. Here with Windows Latin-1.

have you tried Scanner.nextByte()? make a new scanner with the file you want to parse as the input and use a for loop to create your array.

Not able to process big file inside a zip file using ZipInputStream

I am having a below mentioned java class which extracts a zip, and one by one convert its content to string and print to console.
Problem is, when the file present inside the zip is big ~80KB. Entire content is not getting displayed (only 3/4 of the data is getting converted to string and displayed in console).
Secondly below mentioned code is introducing null/space in between and also if the file size is small ~1KB
what is wrong in below mentioned code.
public static void main(String[] args) throws Exception {
byte[] buf = new byte[1024];
final int BUFFER = 1024;
String fName = "c:\\DOC00001.zip";
ZipInputStream zinstream = new ZipInputStream(
new FileInputStream(fName));
ZipEntry zentry = zinstream.getNextEntry();
while (zentry != null) {
byte data[] = new byte[BUFFER];
ByteArrayOutputStream out = new ByteArrayOutputStream();
while ((zinstream.read(data, 0, BUFFER)) != -1) {
out.write(data);
}
InputStream is = new ByteArrayInputStream(out.toByteArray());
StringWriter writer = new StringWriter();
IOUtils.copy(is, writer, "UTF-8");
String response = writer.toString();
System.out.println(response);
zentry = zinstream.getNextEntry();
}
zinstream.close();
}

The read method is not guaranteed to read a full buffer; the number of bytes that have been read is returned. The correct way to extract data from a zip file, or any InputStream in general, would be:
byte[] data = new byte[BUFFER];
ByteArrayOutputStream out = new ByteArrayOutputStream();
int bytesRead;
while ((bytesRead = zinstream.read(data, 0, BUFFER)) != -1) {
out.write(data, 0, bytesRead);
}
Or, since you are already using IOUtils,
ByteArrayOutputStream out = new ByteArrayOutputStream();
IOUtils.copy(zinstream, out);
Or, given that you write to a ByteArrayOutputStream only to later write to a String, you can skip the ByteArrayOutputStream entirely:
while (zentry != null) {
StringWriter writer = new StringWriter();
IOUtils.copy(zinstream, writer, "UTF-8");
String response = writer.toString();
System.out.println(response);
zentry = zinstream.getNextEntry();
}

Decompressed video file is not working in Java

Basically i compress video using the customized compressor class in Java. I have assembled my complete code snippets here. My actually problem is, generated video [ A.mp4] from the decompressed byte array is not running. I actually i got this compressor class code over the internet. As i new to Java platform, i am struggling to resolve this problem. Could you please any one help me on this.?
public class CompressionTest
{
public static void main(String[] args)
{
Compressor compressor = new Compressor();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
FileInputStream fis=null;
File file=null;
try
{
URL uri=CompressionTest.class.getResource("/Files/Video.mp4");
file=new File(uri.getPath());
fis = new FileInputStream(file);
}
catch ( FileNotFoundException fnfe )
{
System.out.println( "Unable to open input file");
}
try
{
byte[] videoBytes = getBytesFromFile(file);
System.out.println("CompressionVideoToCompress is: '" +videoBytes + "'");
byte[] bytesCompressed = compressor.compress(videoBytes);
System.out.println("bytesCompressed is: '" +bytesCompressed+ "'");
byte[] bytesDecompressed=compressor.decompress(bytesCompressed);
System.out.println("bytesDecompressed is: '" +bytesDecompressed+ "'");
FileOutputStream out = new FileOutputStream("A.mp4");
out.write(bytesDecompressed,0,bytesDecompressed.length-1);
out.close();
}
catch (IOException e)
{
// TODO Auto-generated catch block
System.out.println("bytesCompressed is: '");
}
}
public static byte[] getBytesFromFile(File file) throws IOException
{
InputStream is = new FileInputStream(file);
// Get the size of the file
long length = file.length();
// You cannot create an array using a long type.
// It needs to be an int type.
// Before converting to an int type, check
// to ensure that file is not larger than Integer.MAX_VALUE.
if (length > Integer.MAX_VALUE) {
// File is too large
}
// Create the byte array to hold the data
byte[] bytes = new byte[1064];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0)
{
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}
}
class Compressor
{
public Compressor()
{}
public byte[] compress(byte[] bytesToCompress)
{
Deflater deflater = new Deflater();
deflater.setInput(bytesToCompress);
deflater.finish();
byte[] bytesCompressed = new byte[Short.MAX_VALUE];
int numberOfBytesAfterCompression = deflater.deflate(bytesCompressed);
byte[] returnValues = new byte[numberOfBytesAfterCompression];
System.arraycopy
(
bytesCompressed,
0,
returnValues,
0,
numberOfBytesAfterCompression
);
return returnValues;
}
public byte[] decompress(byte[] bytesToDecompress)
{
Inflater inflater = new Inflater();
int numberOfBytesToDecompress = bytesToDecompress.length;
inflater.setInput
(
bytesToDecompress,
0,
numberOfBytesToDecompress
);
int compressionFactorMaxLikely = 3;
int bufferSizeInBytes =
numberOfBytesToDecompress
* compressionFactorMaxLikely;
byte[] bytesDecompressed = new byte[bufferSizeInBytes];
byte[] returnValues = null;
try
{
int numberOfBytesAfterDecompression = inflater.inflate(bytesDecompressed);
returnValues = new byte[numberOfBytesAfterDecompression];
System.arraycopy
(
bytesDecompressed,
0,
returnValues,
0,
numberOfBytesAfterDecompression
);
}
catch (DataFormatException dfe)
{
dfe.printStackTrace();
}
inflater.end();
return returnValues;
}
}

I've tested your code by compressing and decompressing a simple TXT file. The code is broken, since the compressed file, when uncompressed, is different from the original one.
Take for granted that the code is broken at least in the getBytesFromFile function. Its logic is tricky and troublesome, since it only allows files up to length 1064 and the check (throwing IOException when a longer file is read) does not work at all. The file gets read only partially and no exception is thrown.
What you are trying to achieve (file compression/decompression) can be done this way. I've tested it and it works, you just need this library.
import java.io.*;
import java.util.zip.*;
import org.apache.commons.io.IOUtils; // <-- get this from http://commons.apache.org/io/index.html
public class CompressionTest2 {
public static void main(String[] args) throws IOException {
File input = new File("input.txt");
File output = new File("output.bin");
Compression.compress(input, output);
File input2 = new File("input2.txt");
Compression.decompress(output, input2);
// At this point, input.txt and input2.txt should be equal
}
}
class Compression {
public static void compress(File input, File output) throws IOException {
FileInputStream fis = new FileInputStream(input);
FileOutputStream fos = new FileOutputStream(output);
GZIPOutputStream gzipStream = new GZIPOutputStream(fos);
IOUtils.copy(fis, gzipStream);
gzipStream.close();
fis.close();
fos.close();
}
public static void decompress(File input, File output) throws IOException {
FileInputStream fis = new FileInputStream(input);
FileOutputStream fos = new FileOutputStream(output);
GZIPInputStream gzipStream = new GZIPInputStream(fis);
IOUtils.copy(gzipStream, fos);
gzipStream.close();
fis.close();
fos.close();
}
}
This code doesn't come from "credible and/or official sources" but at least it works. :)
Moreover, in order to get more answers, adjust the title stating your real problem: your compressed files don't decompress the right way. There is no 'video' stuff here. Moreover, zipping a .mp4 file is no achievement (compression ratio will likely be around 99.99%).

Two tips:
1) Replace getBytesFromFile with a well known API call, either using Apache commons (IOUtils) or java 7 now provides such a method, too.
2) Test compress and decompress by writing a Junit test:
Create a random huge byte array, write it out, read it back and compare it with the created one.