Поскольку Kent Beck отмечает при обсуждении защитных пунктов в Шаблоны Реализации создание стандартной программы иметь однократную и точку выхода...
"должен был предотвратить беспорядок, возможный при вскакивании и из многих местоположений в той же стандартной программе. Это проявило здравый смысл, когда относился к ФОРТРАНУ или программам на языке ассемблера, записанным с большим количеством глобальных данных, где даже понимание, какие операторы выполнялись, было тяжелой работой... с маленькими методами и главным образом локальными данными, это напрасно консервативно".
я нахожу функцию записанной с защитными пунктами намного легче следовать, чем один длинный вложенный набор if then else
операторы.
You basically need a helper method to read a stream into memory. This works pretty well:
public static byte[] readFully(InputStream stream) throws IOException
{
byte[] buffer = new byte[8192];
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int bytesRead;
while ((bytesRead = stream.read(buffer)) != -1)
{
baos.write(buffer, 0, bytesRead);
}
return baos.toByteArray();
}
Then you'd call it with:
public static byte[] loadFile(String sourcePath) throws IOException
{
InputStream inputStream = null;
try
{
inputStream = new FileInputStream(sourcePath);
return readFully(inputStream);
}
finally
{
if (inputStream != null)
{
inputStream.close();
}
}
}
Don't mix up text and binary data - it only leads to tears.
The problem is that you are calling toString()
on the InputStream
object itself. This will return a String
representation of the InputStream
object not the actual PDF document.
You want to read the PDF only as bytes as PDF is a binary format. You will then be able to write out that same byte
array and it will be a valid PDF as it has not been modified.
e.g. to read a file as bytes
File file = new File(sourcePath);
InputStream inputStream = new FileInputStream(file);
byte[] bytes = new byte[file.length()];
inputStream.read(bytes);
Are'nt you creating the pdf file but not actually writing the byte array back? Therefore you cannot open the PDF.
out = new FileOutputStream("D:/ABC_XYZ/1.pdf");
out.Write(b, 0, b.Length);
out.Position = 0;
out.Close();
This is in addition to correctly reading in the PDF to byte array.
Calling toString()
on an InputStream
doesn't do what you think it does. Even if it did, a PDF contains binary data, so you wouldn't want to convert it to a string first.
What you need to do is read from the stream, write the results into a ByteArrayOutputStream
, then convert the ByteArrayOutputStream
into an actual byte
array by calling toByteArray()
:
InputStream inputStream = new FileInputStream(sourcePath);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
int data;
while( (data = inputStream.read()) >= 0 ) {
outputStream.write(data);
}
inputStream.close();
return outputStream.toByteArray();
PDFs may contain binary data and chances are it's getting mangled when you do ToString. It seems to me that you want this:
FileInputStream inputStream = new FileInputStream(sourcePath);
int numberBytes = inputStream .available();
byte bytearray[] = new byte[numberBytes];
inputStream .read(bytearray);