Storing a large binary file
Are there any ways to store a large binary file like 50 MB in the ten files with 5 MB? thanks are there any spe开发者_JS百科cial classes for doing this?
Use a FileInputStream to read the file and a FileOutputStream to write it.
Here a simple (incomplete) example (missing error handling, writes 1K chunks)
public static int split(File file, String name, int size) throws IOException {
FileInputStream input = new FileInputStream(file);
FileOutputStream output = null;
byte[] buffer = new byte[1024];
int count = 0;
boolean done = false;
while (!done) {
output = new FileOutputStream(String.format(name, count));
count += 1;
for (int written = 0; written < size; ) {
int len = input.read(buffer);
if (len == -1) {
done = true;
break;
}
output.write(buffer, 0, len);
written += len;
}
output.close();
}
input.close();
return count;
}
and called like
File input = new File("C:/data/in.gz");
String name = "C:/data/in.gz.part%02d"; // %02d will be replaced by segment number
split(input, name, 5000 * 1024));
Yes, there are. Basically just count the bytes which you write to file and if it hits a certain limit, then stop writing, reset the counter and continue writing to another file using a certain filename pattern so that you can correlate the files with each other. You can do that in a loop. You can learn here how to write to files in Java and for the remnant just apply the primary school maths.
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