Develop Reference

Zip Jasper reports [duplicate]

I am trying to create a zip file of multiple image files. I have succeeded in creating the zip file of all the images but somehow all the images have been hanged to 950 bytes. I don't know whats going wrong here and now I can't open the images were compressed into that zip file.
Here is my code. Can anyone let me know what's going here?
String path="c:\\windows\\twain32";
File f=new File(path);
f.mkdir();
File x=new File("e:\\test");
x.mkdir();
byte []b;
String zipFile="e:\\test\\test.zip";
FileOutputStream fout=new FileOutputStream(zipFile);
ZipOutputStream zout=new ZipOutputStream(new BufferedOutputStream(fout));
File []s=f.listFiles();
for(int i=0;i<s.length;i++)
{
b=new byte[(int)s[i].length()];
FileInputStream fin=new FileInputStream(s[i]);
zout.putNextEntry(new ZipEntry(s[i].getName()));
int length;
while((length=fin.read())>0)
{
zout.write(b,0,length);
}
zout.closeEntry();
fin.close();
}
zout.close();

This is my zip function I always use for any file structures:
public static File zip(List<File> files, String filename) {
File zipfile = new File(filename);
// Create a buffer for reading the files
byte[] buf = new byte[1024];
try {
// create the ZIP file
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipfile));
// compress the files
for(int i=0; i<files.size(); i++) {
FileInputStream in = new FileInputStream(files.get(i).getCanonicalName());
// add ZIP entry to output stream
out.putNextEntry(new ZipEntry(files.get(i).getName()));
// transfer bytes from the file to the ZIP file
int len;
while((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
// complete the entry
out.closeEntry();
in.close();
}
// complete the ZIP file
out.close();
return zipfile;
} catch (IOException ex) {
System.err.println(ex.getMessage());
}
return null;
}

Change this:
while((length=fin.read())>0)
to this:
while((length=fin.read(b, 0, 1024))>0)
And set buffer size to 1024 bytes:
b=new byte[1024];

How to download a dataset using java

I want to make an app that will download all the paper mentioned in the image by taking the domain as input. i have been able to download a single file from some other website but was unable to download a paper form acm digital library.
what i need to do is download the entire data set.
here is the code that i used to download a single file.
String fileName = "1.txt";
URL link = new URL("http://shayconcepts.com");
InputStream in = new BufferedInputStream(link.openStream());
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[2048];
int n = 0;
while (-1!=(n=in.read(buf)))
{
out.write(buf, 0, n);
}
out.close();
in.close();
byte[] response = out.toByteArray();
FileOutputStream fos = new FileOutputStream(fileName);
fos.write(response);
fos.close();
How can I modify it to download entire data set

Unable to unzip zip file created with java

I have a list of files from different locations. I create a zip file using the following the code which works without error. But when I try to unzip the file in Windows using Extract All it fails seeing unable to find any bytes, yet if I double click into the zip file itself with Windows Explorer I can see the files and individual ones can be opened and contains the correct data
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zipFile));
for (File next : files)
{
ZipEntry zipEntry = new ZipEntry(next.getName());
zos.putNextEntry(zipEntry);
FileInputStream in = new FileInputStream(next);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0)
{
zos.write(buf, 0, len);
}
zos.closeEntry();
in.close();
}
zos.close();

This may or may not be related but I've found using fixed byte length can lead to a loss of new line characters.
This may help:
final byte[] newLine = System.getProperty(
"line.separator").getBytes("UTF-8");
while ((line = in.readLine()) != null)
final byte[] buffer = line.getBytes("UTF-8");
out.write(buffer, 0, buffer.length);
out.write(newLine, 0, newLine.length);
}

Writing inputstream to file - no file found

I'm trying to write inputstream to a file, but it never gets written on disk, I just get the error file doesnt exist. The file I open is a drawable icluded in the project, I would like to save it to sd card. This is what I have so far:
File storagePath = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/tester");
InputStream inputStream = getResources().openRawResource(R.drawable.test);
OutputStream out = new FileOutputStream(new File(storagePath, "test.png"));
byte buffer[] = new byte[900];
int len;
while ((len = inputStream.read(buf)) > 0)
out.write(buffer, 0, len);
out.close();
inputStream.close();

Your tester directory doesn't exist. Check for it and create it if necessary before opening your FileOutputStream.

Saving BufferedImage using zip compression

How would I go about saving a BufferedImage straight to a zip file.
Here is my current code for saving my BufferedImage to a zip file but I do not know how to convert the BufferedImage to a InputStream so that it can be saved to the zip file.
If possible I need to save the BufferedImage straight from RAM without saving it to HDD first
byte[] buffer = new byte[1024];
try
{
FileOutputStream outputStream = new FileOutputStream(PathName + imageData.getFileNumber() + ".zip");
ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream);
ZipEntry imageZipOutput = new ZipEntry(imageData.getFileNumber() + ".png");
zipOutputStream.putNextEntry(imageZipOutput);
//the BufferedImage is stored in imageData.getImage();
//how would I parse the BufferedImage to the InputStream below without saving the png first but straight from RAM
InputStream in = new InputStream();
int len;
while ((len = in.read(buffer)) > 0)
{
zipOutputStream.write(buffer, 0, len);
}
in.close();
zipOutputStream.closeEntry();
zipOutputStream.close();
}

Use ImageIO.write(RenderedImage im,String formatName, OutputStream output) to write the output. Pass a ZipOutputStream for the OutputStream parameter.
Check this page for more info.