Java UnZip
What wrong with my code ?
the unzipped file contain only 8xx valid bytes.
e.g.
from byte 1 to byte 8xx is okey
but from (8xx + 1)th byte to the last byte of the file are 20H
// code
public void doUnZip(String path, String fileName){
try {
File f = new File(path + java.io.File.separatorChar + fileName);
ZipFile zf = new ZipFile(f);
Enumeration enFile = zf.entries();
while (enFile.hasMoreElements()) {
ZipEntry ze = (ZipEntry)enFile.nextElement();
String entryName = ze.getName();
int size = (int)ze.getSize();
byte b[] = new byte[size];
InputStream zis = zf.getInputStream(ze);
zis.read(b);
zis.close();
String content = new String(b);
FileOutputStream fos = new FileOutputStream(path + java.io.File.separatorChar + entryName);
fos.write(b);
fos.close();
System.out.println(entryName + " unzipped.");
} catch (Exception e) {
e.printStackTrace();
Hi,
at first glance I'd say that it may be datatype differences, getSize() returns a long whereas you assign it to an int.
Give it a go.
cheers
Dave
Similar Messages
-
Hello there,
I tried to create two small programs: Zip and UnZip, using the java.util.zip package. The Zip file works perfectly and WinAce can read the files zipped. But the UnZip program doesn't seem to work: it unzips
the files almost correctly. I unzipped a text file and it's readable, but except for the normal characters that appeared in the original text, some other not-displayable characters appear at certain points (quite many since the unzipped files are a few kilob bigger that the original not-zipped file). I really don't understand what the problem is. Well, actually, I didn't read any tutorial about using java.util.zip, I just read the API documentation and I sorted out a way of zipping and unzipping. Please, if you can, tell me what is the problem with the program:
public class UnZip
public static void main(String[] arg)
try
if (arg.length < 1)
System.out.println("Usage: java UnZip <zip file> [to dir]");
System.exit(0);
String dir = "";
if (arg.length > 1)
dir = arg[1] + System.getProperty("file.separator");
File f = new File(arg[1]);
if (!f.exists()) f.mkdirs();
System.out.println("Decompressing files from file " + arg[0]);
ZipFile read = null;
try
read = new ZipFile(arg[0]);
catch (ZipException ex)
System.err.println("Zip error when reading file " + arg[0]);
System.exit(1);
catch (IOException ex)
System.err.println("I/O Exception when reading file " + arg[0]);
System.exit(1);
Enumeration en = read.entries();
while (en.hasMoreElements())
ZipEntry entry = (ZipEntry) en.nextElement();
System.out.println("\tDecompressing file " + entry.getName());
FileOutputStream out;
try
out = new FileOutputStream(dir + entry.getName());
catch (FileNotFoundException ex)
System.err.println("\tCannot write down to file " + dir + entry.getName());
continue;
InputStream re = read.getInputStream(entry);
int av = 0;
while ((av = re.available()) != 0)
byte[] b = new byte[av < 64 ? av : 64];
re.read(b);
out.write(b);
out.close();
System.out.println("\tDone decompressing file " + entry.getName());
read.close();
System.out.println("Done decompressing files");
catch (Exception e)
new File(arg[1]).delete();
e.printStackTrace(System.err);
}It is the following code which has a swapped conditional expression,
and also I would loop differently.
int av = 0;
while ((av = re.available()) != 0)
byte[] b = new byte[av < 64 ? av : 64];
re.read(b);
out.write(b);
}Move the byte buffer outside, and better think in kilobytes.
Read is waiting and forcing an actual read, so it seems
safer than an available.
byte[] buffer = new byte[1024];
for (;;) {
int nread = re.read(buffer);
if (nread < 0)
break;
out.write(buffer, 0, nread); -
Zipfile and zipinputstream code
Hi!
I need to unzip something that is in a bytearrayoutputstream. Since zipfile and zipinputstream does not receive bytearrayoutputstream I thought of creating my own but I don't know how to do that. I need someone to help me with the code. I need a code not advice please.
All I know is that it should extend to zipfile .
Please help** a simple unZIP tool
** ex. java UnZip file.zip file1 to unzip file 1 from file.zip
** java UnZip file.zip to unzip file.zip
import java.io.*;
import java.util.*;
import java.util.zip.*;
import java.text.*;
class UnZip {
public static void main(String args[]) throws IOException {
InputStream in = new BufferedInputStream(new FileInputStream(args[0]));
ZipInputStream zin = new ZipInputStream(in);
ZipEntry e;
while((e=zin.getNextEntry())!= null) {
if (args.length > 1) {
if (e.getName().equals(args[1])) {
unzip(zin, args[1]);
break;
unzip(zin, e.getName());
zin.close();
public static void unzip(ZipInputStream zin, String s) throws IOException {
System.out.println("unzipping " + s);
FileOutputStream out = new FileOutputStream(s);
byte [] b = new byte[512];
int len = 0;
while ( (len=zin.read(b))!= -1 ) {
out.write(b,0,len);
out.close();
Courtesy of : http://www.rgagnon.com/javadetails/java-0067.html and http://www.rgagnon.com/howto.html -
Unzippping into specified directory
hello!
i want to unzip my archive into a generated directory in the users home-directory.
ive tried this:
class UnZip
public static final int EOF = -1;
public UnZip(String [] args)
if ( args.length != 1 )
System.out.println( "Usage:java UnZip zipfile" );
else
try
ZipFile zf = new ZipFile( args[0] );
for ( Enumeration<? extends ZipEntry> e = zf.entries(); e.hasMoreElements(); )
ZipEntry target = e.nextElement();
System.out.print( target.getName() + " ." );
saveEntry( zf, target );
System.out.println( ". unpacked" );
catch( FileNotFoundException e ) {
System.out.println( "zipfile not found" );
catch( ZipException e ) {
System.out.println( "zip error..." );
catch( IOException e ) {
System.out.println( "IO error..." );
void saveEntry( ZipFile zf, ZipEntry target )
throws ZipException,IOException
File file = new File( target.getName() );
if ( target.isDirectory() )
file.mkdirs();
else
InputStream is = zf.getInputStream( target );
BufferedInputStream bis = new BufferedInputStream( is );
new File( file.getParent() ).mkdirs();
String homedir = System.getProperty("user.home");
File fd = new File(homedir + "/mp/");
fd.mkdir();
FileOutputStream fos = new FileOutputStream(homedir + "/mp/" + file );
BufferedOutputStream bos = new BufferedOutputStream(fos);
final int EOF = -1;
for ( int c; ( c = bis.read() ) != EOF; ) // oder schneller
bos.write( (byte)c );
bos.close();
fos.close();
}which ends up with a FileNotFoundException e,
while same code but with
FileOutputStream fos = new FileOutputStream( file );
BufferedOutputStream bos = new BufferedOutputStream(fos);
////*************************************************************/////////////////////it seems to work, its unpacking them files somewhere.
what do i dont see?ive just copied all the unzip example ive found into the constructor for testing purposes, its not the way i code :-),i was just playing around with code snippets about unzipping.
the last mkdir is just to verify that this directory exist, the others i thought produce that directorysrtucture which is in the zipfile?
the code ive changed:
class UnZip
public static final int EOF = -1;
public UnZip(String [] args)
if ( args.length != 1 )
System.out.println( "Usage:java UnZip zipfile" );
else
try
ZipFile zf = new ZipFile( args[0] );
for ( Enumeration<? extends ZipEntry> e = zf.entries(); e.hasMoreElements(); )
ZipEntry target = e.nextElement();
System.out.print( target.getName() + " ." );
saveEntry( zf, target );
System.out.println( ". unpacked" );
catch( FileNotFoundException e ) {
System.out.println( "zipfile not found" );
catch( ZipException e ) {
System.out.println( "zip error..." );
catch( IOException e ) {
System.out.println( "IO error..." );
void saveEntry( ZipFile zf, ZipEntry target )
throws ZipException,IOException
File file = new File( target.getName() );
if ( target.isDirectory() )
file.mkdirs();
else
InputStream is = zf.getInputStream( target );
BufferedInputStream bis = new BufferedInputStream( is );
new File( file.getParent() ).mkdirs();
String homedir = System.getProperty("user.home");
File fd = new File(homedir,"mp");
fd.mkdir();
FileOutputStream fos = new FileOutputStream(new File(fd,file.getPath()));
BufferedOutputStream bos = new BufferedOutputStream(fos);
final int EOF = -1;
for ( int c; ( c = bis.read() ) != EOF; ) // oder schneller
bos.write( (byte)c );
bos.close();
fos.close();
}the output:
run-single:
derby/ .. unpacked
derby/derby.log .C:\Dokumente und Einstellungen\anti/mp/derby\derby.log
zipfile not found
java.io.FileNotFoundException: C:\Dokumente und Einstellungen\anti\mp\derby\derby.log (Das System kann den angegebenen Pfad nicht finden)
at java.io.FileOutputStream.open(Native Method)
at java.io.FileOutputStream.<init>(FileOutputStream.java:179)
at java.io.FileOutputStream.<init>(FileOutputStream.java:131)
at mxnew.installClass$UnZip.saveEntry(installClass.java:86)
at mxnew.installClass$UnZip.<init>(installClass.java:48)
the error line is the one with the FileOutputStream fos = new FileOutputStream(new File(fd,file.getPath())); -
hello!
I m trying to make a jar file using the API. When the jar tool is used for the same manifest file, it is correctly written and an executable jar is created. When I use the API, the jar file is made but it is nor executable. Here is that part of code:
jar = new File(parent, jarName);
System.out.println("Executing jar command...");
//create jar file here
Manifest mf = new Manifest(new FileInputStream(manifest));
fos = new FileOutputStream(jar);
jos = new JarOutputStream(new BufferedOutputStream(fos), mf);
BufferedInputStream reader = null;
byte[] data = new byte[BUFFER];
int byteCount = 0;
for(int i = 0; i < fileNames.length; i++)
System.out.println("Adding " + fileNames);
FileInputStream fis = new FileInputStream(fileNames);
reader = new BufferedInputStream(fis, BUFFER);
JarEntry entry = new JarEntry(new ZipEntry(fileNames));
jos.putNextEntry(entry);
while((byteCount = reader.read(data,0,BUFFER)) != -1)
jos.write(data, 0, byteCount);
}//end while
reader.close();
}//end for
jos.close();//close jar output stream
fos.close();
I m sure someone will be kind and intelligent enough to solve the problem. Thank you!
UmerA jar file is simply a Zip file. So the two API's are quite similar. First, you create a CRC - that is a way to make sure that the file isn't corrupted and that all the bytes are there (it's a polynominal algorithm that returns a number which is written in the Zip(Jar) file as well). Each entry is a file or directory. Before writing any data to the Zip(Jar) file, you have to write info on the actual file (like name, path, length etc). That's why you use putNextEntry(). Each file can have it's storing methods, although the most common is to use the "default" methods (built in the ZipOutputStream/JarOutputStream)
But in this example you set the storing methods on the entry. You use the setMethod() method to switch between either storing or compression (don't know why, but in this example you don't compress the file - you should). I myself don't use the setSize() and setCompressedSize() methods at all (and it works fine). Don't know exactly what are the implications of using them. Neither do I use the setCrc() method (If I think a little, I've only used this API once - I don't use it that much), but it's quite straightforward. It's used to check that the data is ok, and since the CRC number is the result of an algorithm, it needs to know the bytes of UNCOMPRESSED data: that's why you use crc.update() on the bytes. After that you actually write all the info set before to the Zip (Jar) file using putNextEntry(). But remember that a ZipEntry doesn't have any data. You'll have to write it yourself: thus the need for the write method: Here are two small programs I used for Zipping and Unzipping. Changing them to work for Jar files is extremely simple:
//Zip.java
import java.io.*;
import java.util.zip.*;
public class Zip
public static void main(String[] arg)
try
if (arg.length < 3)
System.out.println("Usage: java Zip <0-9> <zip file> <file 1> [file 2] [file 3] ...");
System.exit(0);
System.out.println("Compressing files into file " + arg[1]);
ZipOutputStream out = null;
try
out = new ZipOutputStream(new FileOutputStream(arg[1]));
catch (FileNotFoundException ex)
System.out.println("Cannot create file " + arg[1]);
System.exit(1);
try
out.setLevel(Integer.parseInt(arg[0]));
catch (IllegalArgumentException ex)
System.out.println("Illegal compression level");
new File(arg[1]).delete();
System.exit(1);
for (int i=2; i<arg.length; i++)
System.out.println("\tCompressing file " + (i-1));
FileInputStream read = null;
try
read = new FileInputStream(arg);
catch (FileNotFoundException ex)
System.out.println("\tCannot find file " + arg[i]);
continue;
out.putNextEntry(new ZipEntry(arg[i]));
int av = 0;
while ((av = read.available()) != 0)
byte[] b = new byte[av < 64 ? av : 64];
read.read(b);
out.write(b);
out.closeEntry();
read.close();
System.out.println("\tDone compressing file " + i);
System.out.println("Done compressing");
out.finish();
out.close();
catch (Exception e)
new File(arg[1]).delete();
e.printStackTrace(System.err);
And the unzipping app:
//UnZip.java
import java.io.*;
import java.util.*;
import java.util.zip.*;
public class UnZip
public static void main(String[] arg)
try
if (arg.length < 1)
System.out.println("Usage: java UnZip <zip file> [to dir]");
System.exit(0);
String dir = "";
if (arg.length > 1)
dir = arg[1] + System.getProperty("file.separator");
File f = new File(arg[1]);
if (!f.exists()) f.mkdirs();
System.out.println("Decompressing files from file " + arg[0]);
ZipFile read = null;
try
read = new ZipFile(arg[0]);
catch (ZipException ex)
System.err.println("Zip error when reading file " + arg[0]);
System.exit(1);
catch (IOException ex)
System.err.println("I/O Exception when reading file " + arg[0]);
System.exit(1);
Enumeration en = read.entries();
while (en.hasMoreElements())
ZipEntry entry = (ZipEntry) en.nextElement();
System.out.println("\tDecompressing file " + entry.getName());
FileOutputStream out;
try
out = new FileOutputStream(dir + entry.getName());
catch (FileNotFoundException ex)
System.err.println("\tCannot write down to file " + dir + entry.getName());
continue;
InputStream re = read.getInputStream(entry);
int nRead = 0;
for (byte[] buffer = new byte[1024]; (nRead = re.read(buffer)) != -1; out.write(buffer, 0, nRead));
out.close();
System.out.println("\tDone decompressing file " + entry.getName());
read.close();
System.out.println("Done decompressing files");
catch (Exception e)
new File(arg[1]).delete();
e.printStackTrace(System.err); -
Using Java Embedding Unzip Code and a Trigger File in a BPEL Process
Hello,
Thanks in advance to anyone that contributes with any insight. It is much appreciated. Having said that I will get to the crux of my problem.
I am currently using Oracle 11g. I have created a SOA composite application that incorporates BPEL and Java. I have the code needed to unzip and extract compressed folders. However, when this was first built out using BPEL it automatically created a web service in the "exposed service" lane and not a file adapter which I believe is needed in order to trigger the process via a start.txt file for example. Based on what I know ... this web service automatically connecting to the BPEL process was simply due to the order of operations, etc. So by creating a 'read' file adapter first and then creating the BPEL process and selecting the template "Define Service Later", it does not automatcially connect the web service to the BPEL process and it will allow me to connect a file adapter to this BPEL process instead ... great. When opening up the BPEL file I then connect a recieve component to this file adapter and configure appropriately.
Essentially, my objective in setting up a trigger to start this unzip process is due to the BPEL process before that outputs or writes the .zip folder to the same directory that I want to poll and/or trigger via a start.txt file. I can get this process to work with a webservice connecting to the BPEL process and by using a Java Embedded in BPEL file, which in turns calls the package/ class that has the java code needed to unzip.
For some reason whenever I try to use a file adapter instead of the native web service that gets created (as mentioned above) it doesn't work. It seems to build or compile just fine however, I am getting errors when I try to deploy.
Note: The Java code contains all the paths where the zip file is to be taken from and extracted to. So because this is in the code I don't need the file adapter to handle this. I just want to use the file adapter so that I can trigger the process via start.txt or something of that nature.
Thanks to anyone that has any suggestions.
Kind Regards,
Kevin
Errors when attempting to deploy are as follows:
[04:12:54 PM] Error deploying archive sca_Job2_UnZip_rev1.0.jar to partition "default" on server soa_server1 [http://WN017A.homedepot.com:8001]
[04:12:54 PM] HTTP error code returned [500]
[04:12:54 PM] Error message from server:
There was an error deploying the composite on soa_server1: Deployment Failed: Error occurred during deployment of component: BPELProcess1 to service engine: implementation.bpel, for composite: Job2_UnZip: ORABPEL-05250
Error deploying BPEL suitcase.
error while attempting to deploy the BPEL component file "H:\Oracle\Middleware\user_projects\domains\Dev_Acorde\servers\soa_server1\dc\soa_d78eb301-314c-422a-a748-bcfe7d0906e8"; the exception reported is: java.lang.RuntimeException: failed to compile execlets of BPELProcess1
This error contained an exception thrown by the underlying deployment module.
Verify the exception trace in the log (with logging level set to debug mode).
[04:12:54 PM] Check server log for more details.
[04:12:54 PM] Error deploying archive sca_Job2_UnZip_rev1.0.jar to partition "default" on server soa_server1 [http://WN017A.homedepot.com:8001]
[04:12:54 PM] #### Deployment incomplete. ####
[04:12:54 PM] Error deploying archive file:/C:/JDeveloper/mywork/Job2_UnZip/Job2_UnZip/deploy/sca_Job2_UnZip_rev1.0.jar
(oracle.tip.tools.ide.fabric.deploy.common.SOARemoteDeployer)Just wanted to provide a screenshot of the BPEL file as supporting documentation to better illustrate my issue.
Thanks so much,
Kevin -
ABAP- JAVA : How to unzip a zip file sent by ABAP
Hello,
We are using JCO to exchange the XML strings (File Sizes can range upto couple of MBs) between ABAP and JAVA. We were earlier using a STRING parameter for XML data exchange. This approach was resulting in huge performance overheads. As per our initial performance investigations, we have identified that time taken for XML exchange using JCO is the major bottlenecks.
Currently we are evaluating Zip - Exchange - Unzip mechanism for XML exchange.
We now try to ZIP the export content using following ABAP code:
TRY.
CALL METHOD cl_abap_gzip=>compress_text
EXPORTING
text_in = lv_xmlstring
IMPORTING
gzip_out = ev_xmlstring.
This returns an XSTRING (zipped) which is lesser in size as compared to the earlier xml STRING.For zipping the XML String this code works fine. But on java end on using the following code (for unzipping):
public static String unzipStringFromBytes( byte[] bytes ) throws IOException
ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
BufferedInputStream bufis = new BufferedInputStream(new InflaterInputStream(bis));
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int len;
while( (len = bufis.read(buf)) > 0 )
bos.write(buf, 0, len);
String retval = bos.toString();
bis.close();
bufis.close();
bos.close();
return retval;
We get the following error:
java.util.zip.DataFormatException: unknown compression method
at java.util.zip.Inflater.inflateBytes(Native Method)
at java.util.zip.Inflater.inflate(Inflater.java:215)
Please share java code snippet which we can use in our program to retrieve our initial XML string.
Best Regards,
AayushHi,
i took a sequence '0123456789' and gziped it with your ABAP code snipped.
Result is in HEX:
'33 30 34 32 36 31 35 33 B7 B0 04 00'
Than i took an good old gzip executable and gzipped a text file with the same sequence in compression mode 6(default of ABAP Method).
Result in HEX:
'1F 8B 08 08 BA B1 D1 45 00 0B 31 2E 74 78 74 00'
'33 30 34 32 36 31 35 33 B7 B0 04 00 C6 C7 84 A6' <-- quiet similar with ABAP gzip data
'0A 00 00 00'
It seems that some gzip headers and trailers are missing from ABAP Processor's output, i don't know why, maybe it will help you to fake the file headers's to your data section: http://www.gzip.org/zlib/rfc-gzip.html
Other topic is your Exception: java.util.zip.Inflater.inflate(Inflater.java:215)
Inflater is used for ZLIB compressed files, try to pass your InputStream to an Object of [java.util.zip.GZIPInputStream] like:
http://www.galileocomputing.de/openbook/javainsel6/javainsel_12_010.htm [Listing 12.29]
Let me know if it works and have fun..... -
Zipped files created with Java won't unzip with Java
Hello there,
I have written a class for unzipping a zip file using the 'ZipFile' class. It works perfectly fine when I extract zip files that have been created with XP, Winzip, or Winrar.
I am now experimenting with creating zip files using the ZipOutputStream (http://forum.java.sun.com/thread.jspa?forumID=256&threadID=366550 by author smeee). The code works great for creating the zip file, but when I try and unzip it with the zipfile class mentioned above it throws an exception.
The error that the following code gives me when it tries to convert an element from the enumeration to a ZipEntry is this: java.io.FileNotFoundException: C:\testfiles\out\high\BAUMAN\00001.jpg (The system cannot find the path specified)
NOTE: The file is there by the way!!! :-)
See the code for extracting here:
try {
zippy = new ZipFile(fileName);
Enumeration all = zippy.entries();
while (all.hasMoreElements()) {//loop through all zip entries
getFile((ZipEntry)all.nextElement()); <<<=====FAILS HERE
} catch (IOException err) {
System.err.println(err.toString());
return;
}Now if I extract the zip file with winzip, then rezip it with winzip and run the above method again it works with no errors. Any thoughts. Any help would be greatly appreciated.
JaredHello All,
For anyone else who use the forum posting by smeee as a guide to create a zipper (http://forum.java.sun.com/thread.jspa?forumID=256&threadID=366550 by author smeee).
I was tracing through the code and found that there is a statement that adds 1 character (strSource.length()+1) to the source path. This was causing the following bug:
In windows it was placing objects like this \myfolder\myfile.txt
In unix it was placing objects like this yfolder\myfile.txt
Naturally a path like \myfolder... in the zip index was causing problems. I have added a case statement that tests the OS and then adds two chars if windows to compensate for the 'C:' and does nothing if Unix. The code now runs perfectly on either OS.
Thanks for your response guys!
Jared -
I have problem in this unzip java codes
hi all,I have problem in this unzip java codes,I think either the pathway that i put C:.......is wrong or the codes are wrong because when i run it, the zipped folder is not unzipped. So anyone has another set of example or know how to correct it? Thanks!Please post the solution here!
This is the set of codes that i have:
import java.io.*;
import java.util.*;
import java.util.zip.*;
public class Unzip {
public static final void copyInputStream(InputStream in, OutputStream out)
throws IOException
byte[] buffer = new byte[1024];
int len;
while((len = in.read(buffer)) >= 0)
out.write(buffer, 0, len);
in.close();
out.close();
public static final void main(String[] args) {
Enumeration entries;
ZipFile zipFile;
if(args.length != 1) {
System.err.println("Usage: Unzip zipfile");
return;
try {
zipFile = new ZipFile("C:\\Temp\\FolderZiper.zip");
entries = zipFile.entries();
while(entries.hasMoreElements()) {
ZipEntry entry = (ZipEntry)entries.nextElement();
if(entry.isDirectory()) {
// Assume directories are stored parents first then children.
System.err.println("Extracting directory: " + entry.getName());
// This is not robust, just for demonstration purposes.
(new File(entry.getName())).mkdir();
continue;
System.err.println("Extracting file: " + entry.getName());
copyInputStream(zipFile.getInputStream(entry),
new BufferedOutputStream(new FileOutputStream(entry.getName())));
zipFile.close();
} catch (IOException ioe) {
System.err.println("Unhandled exception:");
ioe.printStackTrace();
return;
}What does the program output when it's executed? Can you copy the screen and post it here? More info can help solve the problem.
What exactly is the program supposed to do?
Add some more println() to show the program flow and what the values of key variables are. For example what is in entries after the entries() method is executed?
Some prep work on your part would make it easier for us to help. -
I have a zip file with a nested directory structure, with most folders containing files as well as other directories. I want to do use java's zip utilities to unzip the file.
Here's the twist: For each file (but not each directory) I want to read the file, write some extra text to the end of it, and then write it out into its appropriate place in the directory tree.
I know I get can use entries() to get an enumeration of entries in the zip file, and then I could use recursion to spider down into directories. But I thought maybe there was a simpler way, so that I didn't have to write the spidering code myself. Seems like this would be a common problem...
Thanks for any ideas/code,
JohnI know I get can use entries() to get an enumeration
of entries in the zip file, and then I could use
recursion to spider down into directories. But IUhm, Zips are flat, aren't they? No need for recursion... all entries are at top level. -
Using unzip from unix in java-code ...
Hi people,
i have problem, i want to use the command unzip from unix, to unzip a zip-file, the commend unzip must invoke from java-code. Can someone help me. I use the zip-api, but i have 100Mb zip-file, it needs very long time to unzip the zip-file.
thanks for your help ...ok, not sure how much improvement this will give in general, but its given a reliable 25% speed increase on my mini tests
using the nio libraries will also get you a lot further, and is the way to go if you are very keen on speed
asjf
import java.awt.*;
import java.io.*;
import java.util.*;
import java.util.zip.*;
import javax.swing.*;
public class Unzipper {
private Unzipper() {}
private static byte[] buffer = new byte[16384];
public static void unzip(File file, Component parentComponent, File outputDir) throws ZipException, IOException {
unzip(new ZipFile(file), parentComponent, outputDir);
public static void unzip(File file, int mode, Component parentComponent, File outputDir) throws IOException {
unzip(new ZipFile(file, mode), parentComponent, outputDir);
public static void unzip(String name, Component parentComponent, File outputDir) throws IOException {
unzip(new ZipFile(name), parentComponent, outputDir);
public static void unzip(ZipFile zip, Component parentComponent, File outputDir) throws IOException {
if ( zip == null) {
throw new NullPointerException("outputDir is null");
int size = zip.size();
if (size > 0) {
if (outputDir == null) {
throw new NullPointerException("outputDir is null");
if (!outputDir.exists()) {
outputDir.mkdirs();
ProgressMonitor monitor =
new ProgressMonitor(parentComponent,
"Unpacking " + zip.getName() + "...", "", 0, size);
monitor.setMillisToDecideToPopup(0);
monitor.setMillisToPopup(0);
Enumeration entries = zip.entries();
for ( int i = 0; entries.hasMoreElements(); ) {
ZipEntry entry = (ZipEntry) entries.nextElement();
/*if (entry.getMethod() == ZipEntry.DEFLATED)
System.out.println(" Inflating: "+entry.getName());
else
System.out.println(" Extracting: "+entry.getName());*/
monitor.setNote(entry.getName());
File File = new File(outputDir, entry.getName());
File.getParentFile().mkdirs();
if (!entry.isDirectory()) {
InputStream in = null;
OutputStream out = null;
try {
in = zip.getInputStream(entry);
out = new FileOutputStream(File);
for (int n = 0; (n = in.read(buffer)) > -1; )
out.write(buffer, 0, n);
monitor.setProgress(++i);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
public static void main(String[] args) throws ZipException, IOException
if (args.length !=2) {
System.err.println("Usage: java Unzipper <zip file> <output dir>");
System.exit(1);
long start = -System.currentTimeMillis();
unzip(args[0], null, new File(args[1]));
System.out.println(start+System.currentTimeMillis());
System.exit(0); -
How do I estimate time takes to Zip/Unzip using java.util.zip ?
If I am compressing files or uncompressing zips using java.util.zip is there a way for me to tell the user how long it should take or for perhaps displaying a progress monitor ?
For unzip use the ZipInputStream and pass it a CountingInputStream that keeps track ofr the number of bytes read from it (you write this). This CountingInputStream extends fileInputStream and as such can provide you with information about the total number of bytes available to be read and the number already read. This can give a crude idea of how much work has been done and how much work still needs to be done. It is inaccurate but should be good enoough for a progress bar
As for zipping use the ZipOutputStream and pass it blocks of information. Keep track of the number of blocks you have written and the number you still need to write.
matfud -
hello friends,
Please help me out...iam in urgent help..iam not getting answer for this .. Using zlib java..
I have a zipfile named prabhu.zip
It contains
prabhu\prabhuimage\imagefiles
right now iam able to unzip only files in current folders..i mean prabhu
i want to unzip subfolders also...eg prabhuimage folder..
RIght now only files in current folder is getting unzipped..
please understand this and help me out my friend..
Thanks and Regards,
Prabhuhello friends,
Please help me out...iam in urgent help..iam not getting answer for this .. Using zlib java..
I have a zipfile named prabhu.zip
It contains
prabhu\prabhuimage\imagefiles
right now iam able to unzip only files in current folders..i mean prabhu
i want to unzip subfolders also...eg prabhuimage folder..
RIght now only files in current folder is getting unzipped..
please understand this and help me out my friend..
Thanks and Regards,
Prabhu -
Unzipping zipfile with sub folders...using zlib java
Hello,
I am encounterig a problem while unzipping a zipfile using zlib.The zip file contaings subdirectories.so i am not able to unzip the zipfile.Since my code is able to unzip only the files which are in current directory.Please help me out to unzip the subdirectories using zlib.
Please find my below code..for unzip the files in current directory..
String destinationname = rootFolder.getAbsolutePath();
byte[] buf = new byte[1024];
ZipInputStream zipinputstream = null;
ZipEntry zipentry;
zipinputstream = new ZipInputStream(
new FileInputStream(destinationname+"\\"+date+".zip"));
zipentry = zipinputstream.getNextEntry();
while (zipentry != null)
//for each entry to be extracted
String entryName = zipentry.getName();
LoggerHtml.debug(entryName);
int n;
FileOutputStream fileoutputstream;
File newFile = new File(entryName);
String directory = newFile.getParent();
if(directory == null)
//break;
fileoutputstream = new FileOutputStream(
entryName);
while ((n = zipinputstream.read(buf, 0, 1024)) > -1)
fileoutputstream.write(buf, 0, n);
fileoutputstream.close();
zipinputstream.closeEntry();
zipentry = zipinputstream.getNextEntry();
Please provide me the coding..It is very urgent...google
code #1
import java.io.*;
import java.util.*;
import java.util.zip.*;
public class unzip
public static void main(String args[])
if(args.length < 1)
System.out.println("Syntax : unzip zip-file destination-dir[optional]");
return;
try
ZipFile zf = new ZipFile(args[0]);
Enumeration zipEnum = zf.entries();
String dir = new String(".");
if( args.length == 2 )
dir = args[1].replace('\\', '/');
if(dir.charAt(dir.length()-1) != '/')
dir += "/";
while( zipEnum.hasMoreElements() )
ZipEntry item = (ZipEntry) zipEnum.nextElement();
if( item.isDirectory() ) //Directory
File newdir = new File( dir + item.getName() );
System.out.print("Creating directory "+newdir+"..");
newdir.mkdir();
System.out.println("Done!");
else //File
String newfile = dir + item.getName();
System.out.print("Writing "+newfile+"..");
InputStream is = zf.getInputStream(item);
FileOutputStream fos = new FileOutputStream(newfile);
int ch;
while( (ch = is.read()) != -1 )
fos.write(ch);
is.close();
fos.close();
System.out.println("Done!");
zf.close();
catch(Exception e)
System.err.println(e);
}code #2
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
* UnZip -- print or unzip a JAR or PKZIP file using java.util.zip. Command-line
* version: extracts files.
* @author Ian Darwin, [email protected] $Id: UnZip.java,v 1.7 2004/03/07
* 17:40:35 ian Exp $
public class UnZip {
/** Constants for mode listing or mode extracting. */
public static final int LIST = 0, EXTRACT = 1;
/** Whether we are extracting or just printing TOC */
protected int mode = LIST;
/** The ZipFile that is used to read an archive */
protected ZipFile zippy;
/** The buffer for reading/writing the ZipFile data */
protected byte[] b;
* Simple main program, construct an UnZipper, process each .ZIP file from
* argv[] through that object.
public static void main(String[] argv) {
UnZip u = new UnZip();
for (int i = 0; i < argv.length; i++) {
if ("-x".equals(argv)) {
u.setMode(EXTRACT);
continue;
String candidate = argv[i];
// System.err.println("Trying path " + candidate);
if (candidate.endsWith(".zip") || candidate.endsWith(".jar"))
u.unZip(candidate);
else
System.err.println("Not a zip file? " + candidate);
System.err.println("All done!");
/** Construct an UnZip object. Just allocate the buffer */
UnZip() {
b = new byte[8092];
/** Set the Mode (list, extract). */
protected void setMode(int m) {
if (m == LIST || m == EXTRACT)
mode = m;
/** Cache of paths we've mkdir()ed. */
protected SortedSet dirsMade;
/** For a given Zip file, process each entry. */
public void unZip(String fileName) {
dirsMade = new TreeSet();
try {
zippy = new ZipFile(fileName);
Enumeration all = zippy.entries();
while (all.hasMoreElements()) {
getFile((ZipEntry) all.nextElement());
} catch (IOException err) {
System.err.println("IO Error: " + err);
return;
protected boolean warnedMkDir = false;
* Process one file from the zip, given its name. Either print the name, or
* create the file on disk.
protected void getFile(ZipEntry e) throws IOException {
String zipName = e.getName();
switch (mode) {
case EXTRACT:
if (zipName.startsWith("/")) {
if (!warnedMkDir)
System.out.println("Ignoring absolute paths");
warnedMkDir = true;
zipName = zipName.substring(1);
// if a directory, just return. We mkdir for every file,
// since some widely-used Zip creators don't put out
// any directory entries, or put them in the wrong place.
if (zipName.endsWith("/")) {
return;
// Else must be a file; open the file for output
// Get the directory part.
int ix = zipName.lastIndexOf('/');
if (ix > 0) {
String dirName = zipName.substring(0, ix);
if (!dirsMade.contains(dirName)) {
File d = new File(dirName);
// If it already exists as a dir, don't do anything
if (!(d.exists() && d.isDirectory())) {
// Try to create the directory, warn if it fails
System.out.println("Creating Directory: " + dirName);
if (!d.mkdirs()) {
System.err.println("Warning: unable to mkdir "
+ dirName);
dirsMade.add(dirName);
System.err.println("Creating " + zipName);
FileOutputStream os = new FileOutputStream(zipName);
InputStream is = zippy.getInputStream(e);
int n = 0;
while ((n = is.read(b)) > 0)
os.write(b, 0, n);
is.close();
os.close();
break;
case LIST:
// Not extracting, just list
if (e.isDirectory()) {
System.out.println("Directory " + zipName);
} else {
System.out.println("File " + zipName);
break;
default:
throw new IllegalStateException("mode value (" + mode + ") bad");
hth -
Cannot use winzip to unzip the zip file zipped by java.util.zip
Hi all,
I use the followcode to create a zip file, and i downlaod it and try to use winzip to unzip this file but fail. The path is correct and i got the zip file. but it just cannot unzip.
pls help
thanks alot.
Kin
int count = 0;
count = ContentDocuments.size();
for (int i = 0; i < bb; i++) {
System.out.println(filenames[i] + "");
// Create a buffer for reading the files
byte[] buf = new byte[10*1024*1024];
try {
String outFilename = MyDir + "zipfile/" + getContentID2()+".zip";
System.out.println("outFilename = " + outFilename);
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outFilename));
for (int i=0; i<filenames.length; i++) {
FileInputStream in = new FileInputStream(filenames);
out.putNextEntry(new ZipEntry(filenames[i]));
int len;
while ((len = in.read(buf)) != -1) {
out.write(buf, 0, len);
out.closeEntry();
in.close();
out.close();
} catch (IOException e) {
System.err.println("zipprocess " + e.getMessage());I've written a replacement zip file creator class. Not much tested but it seems to work, however I've yet to try it with the version of WINZIP that rejected my previous attempts. Oh, and the stored dates are garbage.
* ZipOutputFile.java
* Created on 25 March 2004, 13:08
package zip;
import java.io.IOException;
import java.nio.ByteBuffer;
* <p>Creates a ZIP archive in a file which WINZIP should be able to read.</p>
* <p>Unfortunately zip archives generated by the standard Java class
* {@link java.util.zip.ZipOutputStream}, while adhering to PKZIPs format specification,
* don't appear to be readable by some versions of WinZip and similar utilities. This is
* probably because they use
* a format specified for writing to a non-seakable stream, where the length and CRC of
* a file is writen to a special block following the data. Since the length of the binary
* date is unknown this makes an archive quite complicated to read, and it looks like
* WinZip hasn't bothered.</p>
* <p>All data is Deflated. Close completes the archive, flush terminates the current entry.</p>
* @see java.util.zip.ZipOutputStream
* @author Malcolm McMahon
public class ZipOutputFile extends java.io.OutputStream {
byte[] oneByte = new byte[1];
java.io.RandomAccessFile archive;
public final static short DEFLATE_METHOD = 8;
public final static short VERSION_CODE = 20;
public final static short MIN_VERSION = 10;
public final static int ENTRY_HEADER_MAGIC = 0x04034b50;
public final static int CATALOG_HEADER_MAGIC = 0x02014b50;
public final static int CATALOG_END_MAGIC = 0x06054b50;
private final static short DISC_NUMBER = 0;
ByteBuffer entryHeader = ByteBuffer.wrap(new byte[30]);
ByteBuffer entryLater = ByteBuffer.wrap(new byte[12]);
java.util.zip.CRC32 crcAcc = new java.util.zip.CRC32();
java.util.zip.Deflater def = new java.util.zip.Deflater(java.util.zip.Deflater.DEFLATED, true);
int totalCompressed;
long MSEPOCH;
byte [] deflateBuf = new byte[2048];
public static final long SECONDS_TO_DAYS = 60 * 60 * 24;
* Entry stores info about each file stored
private class Entry {
long offset; // position of header in file
byte[] name;
long crc;
int compressedSize;
int uncompressedSize;
java.util.Date date;
* Contructor also writes initial header.
* @param fileName Name under which data is stored.
* @param date Date to label the file with
* @TODO get the date stored properly
public Entry(String fileName, java.util.Date date) throws IOException {
name = fileName.getBytes();
this.date = date == null ? new java.util.Date() : date;
entryHeader.position(10);
putDate(entryHeader);
entryHeader.putShort(26, (short)name.length);
offset = archive.getFilePointer();
archive.write(entryHeader.array());
archive.write(name);
catalog.add(this);
crcAcc.reset();
totalCompressed = 0;
def.reset();
* Finish writing entry data. Save the lenghts & crc for catalog
* and go back and fill them in in the entry header.
public void close() throws IOException {
def.finish();
while(!def.finished())
deflate();
entryLater.position(0);
crc = crcAcc.getValue();
compressedSize = totalCompressed;
uncompressedSize = def.getTotalIn();
entryLater.putInt((int)crc);
entryLater.putInt(compressedSize);
entryLater.putInt(uncompressedSize);
long eof = archive.getFilePointer();
archive.seek(offset + 14);
archive.write(entryLater.array());
archive.seek(eof);
* Write the catalog data relevant to this entry. Buffer is
* preloaded with fixed data.
* @param buf Buffer to organise fixed lenght part of header
public void writeCatalog(ByteBuffer buf) throws IOException {
buf.position(12);
putDate(buf);
buf.putInt((int)crc);
buf.putInt(compressedSize);
buf.putInt(uncompressedSize);
buf.putShort((short)name.length);
buf.putShort((short)0); // extra field length
buf.putShort((short)0); // file comment length
buf.putShort(DISC_NUMBER); // disk number
buf.putShort((short)0); // internal attributes
buf.putInt(0); // external file attributes
buf.putInt((int)offset); // file position
archive.write(buf.array());
archive.write(name);
* This writes the entries date in MSDOS format.
* @param buf Where to write it
* @TODO Get this generating sane dates
public void putDate(ByteBuffer buf) {
long msTime = (date.getTime() - MSEPOCH) / 1000;
buf.putShort((short)(msTime % SECONDS_TO_DAYS));
buf.putShort((short)(msTime / SECONDS_TO_DAYS));
private Entry entryInProgress = null; // entry currently being written
private java.util.ArrayList catalog = new java.util.ArrayList(12); // all entries
* Start a new output file.
* @param name The name to store as
* @param date Date - null indicates current time
public java.io.OutputStream openEntry(String name, java.util.Date date) throws IOException{
if(entryInProgress != null)
entryInProgress.close();
entryInProgress = new Entry(name, date);
return this;
* Creates a new instance of ZipOutputFile
* @param fd The file to write to
public ZipOutputFile(java.io.File fd) throws IOException {
this(new java.io.RandomAccessFile(fd, "rw"));
* Create new instance of ZipOutputFile from RandomAccessFile
* @param archive RandomAccessFile
public ZipOutputFile(java.io.RandomAccessFile archive) {
this.archive = archive;
entryHeader.order(java.nio.ByteOrder.LITTLE_ENDIAN); // create fixed fields of header
entryLater.order(java.nio.ByteOrder.LITTLE_ENDIAN);
entryHeader.putInt(ENTRY_HEADER_MAGIC);
entryHeader.putShort(MIN_VERSION);
entryHeader.putShort((short)0); // general purpose flag
entryHeader.putShort(DEFLATE_METHOD);
java.util.Calendar cal = java.util.Calendar.getInstance();
cal.clear();
cal.set(java.util.Calendar.YEAR, 1950);
cal.set(java.util.Calendar.DAY_OF_MONTH, 1);
// def.setStrategy(Deflater.HUFFMAN_ONLY);
MSEPOCH = cal.getTimeInMillis();
* Writes the master catalogue and postamble and closes the archive file.
public void close() throws IOException{
if(entryInProgress != null)
entryInProgress.close();
ByteBuffer catEntry = ByteBuffer.wrap(new byte[46]);
catEntry.order(java.nio.ByteOrder.LITTLE_ENDIAN);
catEntry.putInt(CATALOG_HEADER_MAGIC);
catEntry.putShort(VERSION_CODE);
catEntry.putShort(MIN_VERSION);
catEntry.putShort((short)0);
catEntry.putShort(DEFLATE_METHOD);
long catStart = archive.getFilePointer();
for(java.util.Iterator it = catalog.iterator(); it.hasNext();) {
((Entry)it.next()).writeCatalog(catEntry);
catEntry.position(0);
catEntry.putInt(CATALOG_END_MAGIC);
catEntry.putShort(DISC_NUMBER);
catEntry.putShort(DISC_NUMBER);
catEntry.putShort((short)catalog.size());
catEntry.putShort((short)catalog.size());
catEntry.putInt((int)(archive.getFilePointer() - catStart));
catEntry.putInt((int)catStart);
catEntry.putShort((short)0);
archive.write(catEntry.array(), 0, catEntry.position());
archive.setLength(archive.getFilePointer()); // truncate if old file
archive.close();
def.end();
* Closes entry in progress.
public void flush() throws IOException{
if(entryInProgress == null)
throw new IllegalStateException("Must call openEntry before writing");
entryInProgress.close();
entryInProgress = null;
* Standard write routine. Defined by {@link java.io.OutputStream}.
* Can only be used once openEntry has defined the file.
* @param b Bytes to write
public void write(byte[] b) throws IOException{
if(entryInProgress == null)
throw new IllegalStateException("Must call openEntry before writing");
crcAcc.update(b);
def.setInput(b);
while(!def.needsInput())
deflate();
* Standard write routine. Defined by {@link java.io.OutputStream}.
* Can only be used once openEntry has defined the file.
* @param b Bytes to write
public void write(int b) throws IOException{
oneByte[0] = (byte)b;
crcAcc.update(b);
write(oneByte, 0, 1);
* Standard write routine. Defined by {@link java.io.OutputStream}.
* Can only be used once openEntry has defined the file.
* @param b Bytes to write
* @param off Start offset
* @param len Byte count
public void write(byte[] b, int off, int len) throws IOException{
if(entryInProgress == null)
throw new IllegalStateException("Must call openEntry before writing");
crcAcc.update(b, off, len);
def.setInput(b, off, len);
while(!def.needsInput())
deflate();
* Gets a buffer full of coded data from the deflater and writes it to archive.
private void deflate() throws IOException {
int len = def.deflate(deflateBuf);
totalCompressed += len;
if(len > 0)
archive.write(deflateBuf, 0, len);
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