| 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
|
Creates
a new or empty archive.
|
|
t
|
Lists
the table of contents.
|
|
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
|