IO Section Index | Page 5

This piece uncompresses every entry of a ZIP file and puts them into a Vector. ZipEntry anEntry = null; Vector entriesList = new Vector(); try { URL aURL = new URL ("http://localhost/wwwr...more

Create a new class (there are people that consider this a waste and use anonymous classes) that implements the FilenameFilter. This is an example for filtering all the XML files in a directory: im...more

You can use the Unicode symbol: u20AC Keep in mind that when you use System.out, it strips the high order byte from the output. In other words, you can't use System.out.println("u20AC") to get a...more

To recursively get all files under a specific directory, just keep calling listFiles() on the File that is returned, if it is a directory (isDirectory() returns true). Here is what it looks like.....more

You need to use the facilities of java.util.zip.ZipOutputStream and java.util.zip.ZipEntry. Here's a simple example that makes a zip file and writes three tiny text files into it. import java.i...more

You have to go through the entire file. try { LineNumberReader lnr = new LineNumberReader(new FileReader(filename)); String s; while ((s = lnr.readLine()) != null); System.out.println("L...more

The piped I/O streams are for inter-thread communication. They manage the synchronization across thread boundaries of the buffer. See Is there any way to communicate between two classes... for an ...more

Printing is done with AWT classes and thus covered in the AWT FAQ. See How do I print a multi-page text document? for one example, though the API has changed with every release of Java.more

The compression algorithm is the same (Lempel-Ziv derivative LZ-77-deflate). The difference is that GZIP format is used to compress a single file, and ZIP is used to compress many files in a singl...more

Java has no built-in support for disk or file spanning. However, it should be easy to do this on your own. I would suggest subclassing FileOutputStream to perform checks on the length of the data ...more

Unfortunately, the java.io class that handles file descriptors (java.io.FileDescriptor) doesn't allow you to construct a new one from an integer (which is really what you want). So, the only thin...more

Just like with executing a program just use the the -D flag along with the -jar flag. Here is my test case: public class property { public static void main(String[] args) { System.ou...more

You need to pass in the array "type" after the [ character, and before a ; character. If the type is a class, add the letter L and the fully qualified class name. If the type is a primitive, the t...more

How can I implement the Unix "cksum" command in Java? I'm using a CheckedInputStream and creating a new instance of CRC32 to pass it, but I don't get the same checksum value as cksum give me.more

You can use Integer.parseInt() or Long.parseLong() to convert a hexadecimal representation to a 4-byte int or an 8-byte long, respectively. For example, the Java class file magic number 0xCAFEBAB...more