Bruce Eckel's Thinking in Java | Contents | Prev | Next |
//: GZIPcompress.java // Uses Java 1.1 GZIP compression to compress // a file whose name is passed on the command // line. import java.io.*; import java.util.zip.*; public class GZIPcompress { public static void main(String[] args) { try { BufferedReader in = new BufferedReader( new FileReader(args[0])); BufferedOutputStream out = new BufferedOutputStream( new GZIPOutputStream( new FileOutputStream("test.gz"))); System.out.println("Writing file"); int c; while((c = in.read()) != -1) out.write(c); in.close(); out.close(); System.out.println("Reading file"); BufferedReader in2 = new BufferedReader( new InputStreamReader( new GZIPInputStream( new FileInputStream("test.gz")))); String s; while((s = in2.readLine()) != null) System.out.println(s); } catch(Exception e) { e.printStackTrace(); } } } ///:~
//: ZipCompress.java // Uses Java 1.1 Zip compression to compress // any number of files whose names are passed // on the command line. import java.io.*; import java.util.*; import java.util.zip.*; public class ZipCompress { public static void main(String[] args) { try { FileOutputStream f = new FileOutputStream("test.zip"); CheckedOutputStream csum = new CheckedOutputStream( f, new Adler32()); ZipOutputStream out = new ZipOutputStream( new BufferedOutputStream(csum)); out.setComment("A test of Java Zipping"); // Can't read the above comment, though for(int i = 0; i < args.length; i++) { System.out.println( "Writing file " + args[i]); BufferedReader in = new BufferedReader( new FileReader(args[i])); out.putNextEntry(new ZipEntry(args[i])); int c; while((c = in.read()) != -1) out.write(c); in.close(); } out.close(); // Checksum valid only after the file // has been closed! System.out.println("Checksum: " + csum.getChecksum().getValue()); // Now extract the files: System.out.println("Reading file"); FileInputStream fi = new FileInputStream("test.zip"); CheckedInputStream csumi = new CheckedInputStream( fi, new Adler32()); ZipInputStream in2 = new ZipInputStream( new BufferedInputStream(csumi)); ZipEntry ze; System.out.println("Checksum: " + csumi.getChecksum().getValue()); while((ze = in2.getNextEntry()) != null) { System.out.println("Reading file " + ze); int x; while((x = in2.read()) != -1) System.out.write(x); } in2.close(); // Alternative way to open and read // zip files: ZipFile zf = new ZipFile("test.zip"); Enumeration e = zf.entries(); while(e.hasMoreElements()) { ZipEntry ze2 = (ZipEntry)e.nextElement(); System.out.println("File: " + ze2); // ... and extract the data as before } } catch(Exception e) { e.printStackTrace(); } } } ///:~
c
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Creates
a new or empty archive.
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t
|
Lists
the table of contents.
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x
|
Extracts
all files
|
x
file
|
Extracts
the named file
|
f
|
Says:
“I’m going to give you the name of the file.” If you
don’t use this,
jar
assumes
that its input will come from standard input, or, if it is creating a file, its
output will go to standard output.
|
m
|
Says
that the first argument will be the name of the user-created manifest file
|
v
|
Generates
verbose output describing what
jar
is doing
|
O
|
Only
store the files; doesn’t compress the files (use to create a JAR file
that you can put in your classpath)
|
M
|
Don’t
automatically create a manifest file
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