Java IO.pdf - Nguyen Dang Binh

Java I/O
so throw a java.lang.UnsupportedOperationException. This is a runtime exception, so
you do not have to catch it.
public abstract JarFile getJarFile() throws IOException
The getJarEntry() method returns an immutable JarEntry object for the JAR entry
referred to by this URL. You can read the state of this object, but you cannot change it.
Attempts to do so throw a java.lang.UnsupportedOperationException .
public JarEntry getJarEntry() throws IOException
The getManifest() method returns an immutable Manifest object constructed from the
manifest file in the JAR archive. It returns null if the archive doesn't have a manifest. Again,
you cannot modify this Manifest object, and any attempt to do so will throw an
UnsupportedOperationException.
public Manifest getManifest() throws IOException
The getAttributes() method returns an Attributes object representing the attributes of
the JAR entry this URL refers to. It returns null if the URL refers to a JAR file rather than a
particular entry. To get the attributes of the entire archive, use the getMainAttributes()
method instead.
public Attributes getAttributes() throws IOException
public Attributes getMainAttributes() throws IOException
The getCertificates() method returns an array of java.security.cert.Certificate
objects containing the certificates for the JAR entry this URL refers to (if any). This method
returns null if the URL refers to a JAR file rather than a JAR entry.
public Certificate[] getCertificates() throws IOException
9.6 File Viewer, Part 4
Because of the nature of filter streams, it is relatively straightforward to add decompression
services to the FileDumper program last seen in Chapter 7. Generally, you'll want to
decompress a file before dumping it. Adding decompression does not require a new dump
filter. Instead, it simply requires passing the file through an inflater input stream before
passing it to one of the dump filters. We'll let the user choose from either gzipped or deflated
files with the command-line switches -gz and -deflate. When one of these switches is seen,
the appropriate inflater input stream is selected; it is an error to select both. Example 9.15,
FileDumper4, demonstrates.
Example 9.15. FileDumper4
import java.io.*;
import java.util.zip.*;
import com.macfaq.io.*;
public class FileDumper4 {
public static final int ASC = 0;
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