I have a method which has access to the zip file's name and the zipInputStream object (The zipInputStream actually comes from a service which cannot take any additional changes). I want to save the contents of the zipInputStream as a ZIP file in a particular path on my system. Can someone help me with the best way to do this?
PS: I'm still finding my way around java
Warning: The below causes each entry in the source ZIP file to be decompressed, only to immediately recompress it when copying it to the target ZIP file. As far as I can tell, this is unavoidable if all you have access to is the ZipInputStream. Perhaps someone else knows of a better approach. I would recommend modifying your code to somehow get the raw byte stream of the ZIP file, that way you can just dump the bytes into your target file.
If I understand your goal correctly, you want to copy a ZIP file from one location to another, but you only have access to the ZIP file via a ZipInputStream. If that's the case, then you can implement this by opening a ZipOutputStream to the target file and copying the entries over.
For example:
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
public class Main {
public static void copyZipFile(ZipInputStream in, File target) throws IOException {
try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(target))) {
byte[] buffer = new byte[1024 * 8];
ZipEntry entry;
while ((entry = in.getNextEntry()) != null) {
out.putNextEntry(entry);
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
}
}
}
public static void main(String[] args) {
File target = /* your target file */;
try (ZipInputStream in = /* your ZipInputStream */) {
copyZipFile(in, target);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
It's important you close the streams when done with them (which is done via try-with-resources in the above example).
Note the manual buffer handling can be replaced with InputStream#transferTo(OutputStream) in Java 9+.
I am currently extracting the contents of a war file and then adding some new files to the directory structure and then creating a new war file.
This is all done programatically from Java - but I am wondering if it wouldn't be more efficient to copy the war file and then just append the files - then I wouldn't have to wait so long as the war expands and then has to be compressed again.
I can't seem to find a way to do this in the documentation though or any online examples.
Anyone can give some tips or pointers?
UPDATE:
TrueZip as mentioned in one of the answers seems to be a very good java library to append to a zip file (despite other answers that say it is not possible to do this).
Anyone have experience or feedback on TrueZip or can recommend other similar libaries?
In Java 7 we got Zip File System that allows adding and changing files in zip (jar, war) without manual repackaging.
We can directly write to files inside zip files as in the following example.
Map<String, String> env = new HashMap<>();
env.put("create", "true");
Path path = Paths.get("test.zip");
URI uri = URI.create("jar:" + path.toUri());
try (FileSystem fs = FileSystems.newFileSystem(uri, env))
{
Path nf = fs.getPath("new.txt");
try (Writer writer = Files.newBufferedWriter(nf, StandardCharsets.UTF_8, StandardOpenOption.CREATE)) {
writer.write("hello");
}
}
As others mentioned, it's not possible to append content to an existing zip (or war). However, it's possible to create a new zip on the fly without temporarily writing extracted content to disk. It's hard to guess how much faster this will be, but it's the fastest you can get (at least as far as I know) with standard Java. As mentioned by Carlos Tasada, SevenZipJBindings might squeeze out you some extra seconds, but porting this approach to SevenZipJBindings will still be faster than using temporary files with the same library.
Here's some code that writes the contents of an existing zip (war.zip) and appends an extra file (answer.txt) to a new zip (append.zip). All it takes is Java 5 or later, no extra libraries needed.
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
public class Main {
// 4MB buffer
private static final byte[] BUFFER = new byte[4096 * 1024];
/**
* copy input to output stream - available in several StreamUtils or Streams classes
*/
public static void copy(InputStream input, OutputStream output) throws IOException {
int bytesRead;
while ((bytesRead = input.read(BUFFER))!= -1) {
output.write(BUFFER, 0, bytesRead);
}
}
public static void main(String[] args) throws Exception {
// read war.zip and write to append.zip
ZipFile war = new ZipFile("war.zip");
ZipOutputStream append = new ZipOutputStream(new FileOutputStream("append.zip"));
// first, copy contents from existing war
Enumeration<? extends ZipEntry> entries = war.entries();
while (entries.hasMoreElements()) {
ZipEntry e = entries.nextElement();
System.out.println("copy: " + e.getName());
append.putNextEntry(e);
if (!e.isDirectory()) {
copy(war.getInputStream(e), append);
}
append.closeEntry();
}
// now append some extra content
ZipEntry e = new ZipEntry("answer.txt");
System.out.println("append: " + e.getName());
append.putNextEntry(e);
append.write("42\n".getBytes());
append.closeEntry();
// close
war.close();
append.close();
}
}
I had a similar requirement sometime back - but it was for reading and writing zip archives (.war format should be similar). I tried doing it with the existing Java Zip streams but found the writing part cumbersome - especially when directories where involved.
I'll recommend you to try out the TrueZIP (open source - apache style licensed) library that exposes any archive as a virtual file system into which you can read and write like a normal filesystem. It worked like a charm for me and greatly simplified my development.
You could use this bit of code I wrote
public static void addFilesToZip(File source, File[] files)
{
try
{
File tmpZip = File.createTempFile(source.getName(), null);
tmpZip.delete();
if(!source.renameTo(tmpZip))
{
throw new Exception("Could not make temp file (" + source.getName() + ")");
}
byte[] buffer = new byte[1024];
ZipInputStream zin = new ZipInputStream(new FileInputStream(tmpZip));
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(source));
for(int i = 0; i < files.length; i++)
{
InputStream in = new FileInputStream(files[i]);
out.putNextEntry(new ZipEntry(files[i].getName()));
for(int read = in.read(buffer); read > -1; read = in.read(buffer))
{
out.write(buffer, 0, read);
}
out.closeEntry();
in.close();
}
for(ZipEntry ze = zin.getNextEntry(); ze != null; ze = zin.getNextEntry())
{
out.putNextEntry(ze);
for(int read = zin.read(buffer); read > -1; read = zin.read(buffer))
{
out.write(buffer, 0, read);
}
out.closeEntry();
}
out.close();
tmpZip.delete();
}
catch(Exception e)
{
e.printStackTrace();
}
}
I don't know of a Java library that does what you describe. But what you described is practical. You can do it in .NET, using DotNetZip.
Michael Krauklis is correct that you cannot simply "append" data to a war file or zip file, but it is not because there is an "end of file" indication, strictly speaking, in a war file. It is because the war (zip) format includes a directory, which is normally present at the end of the file, that contains metadata for the various entries in the war file. Naively appending to a war file results in no update to the directory, and so you just have a war file with junk appended to it.
What's necessary is an intelligent class that understands the format, and can read+update a war file or zip file, including the directory as appropriate. DotNetZip does this, without uncompressing/recompressing the unchanged entries, just as you described or desired.
As Cheeso says, there's no way of doing it. AFAIK the zip front-ends are doing exactly the same as you internally.
Anyway if you're worried about the speed of extracting/compressing everything, you may want to try the SevenZipJBindings library.
I covered this library in my blog some months ago (sorry for the auto-promotion). Just as an example, extracting a 104MB zip file using the java.util.zip took me 12 seconds, while using this library took 4 seconds.
In both links you can find examples about how to use it.
Hope it helps.
See this bug report.
Using append mode on any kind of
structured data like zip files or tar
files is not something you can really
expect to work. These file formats
have an intrinsic "end of file"
indication built into the data format.
If you really want to skip the intermediate step of un-waring/re-waring, you could read the war file file, get all the zip entries, then write to a new war file "appending" the new entries you wanted to add. Not perfect, but at least a more automated solution.
Yet Another Solution: You may find code below useful in other situations as well. I have used ant this way to compile Java directories, generating jar files, updating zip files,...
public static void antUpdateZip(String zipFilePath, String libsToAddDir) {
Project p = new Project();
p.init();
Target target = new Target();
target.setName("zip");
Zip task = new Zip();
task.init();
task.setDestFile(new File(zipFilePath));
ZipFileSet zipFileSet = new ZipFileSet();
zipFileSet.setPrefix("WEB-INF/lib");
zipFileSet.setDir(new File(libsToAddDir));
task.addFileset(zipFileSet);
task.setUpdate(true);
task.setProject(p);
task.init();
target.addTask(task);
target.setProject(p);
p.addTarget(target);
DefaultLogger consoleLogger = new DefaultLogger();
consoleLogger.setErrorPrintStream(System.err);
consoleLogger.setOutputPrintStream(System.out);
consoleLogger.setMessageOutputLevel(Project.MSG_DEBUG);
p.addBuildListener(consoleLogger);
try {
// p.fireBuildStarted();
// ProjectHelper helper = ProjectHelper.getProjectHelper();
// p.addReference("ant.projectHelper", helper);
// helper.parse(p, buildFile);
p.executeTarget(target.getName());
// p.fireBuildFinished(null);
} catch (BuildException e) {
p.fireBuildFinished(e);
throw new AssertionError(e);
}
}
this a simple code to get a response with using servlet and send a response
myZipPath = bla bla...
byte[] buf = new byte[8192];
String zipName = "myZip.zip";
String zipPath = myzippath+ File.separator+"pdf" + File.separator+ zipName;
File pdfFile = new File("myPdf.pdf");
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipPath));
ZipEntry zipEntry = new ZipEntry(pdfFile.getName());
out.putNextEntry(zipEntry);
InputStream in = new FileInputStream(pdfFile);
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
out.closeEntry();
in.close();
out.close();
FileInputStream fis = new FileInputStream(zipPath);
response.setContentType("application/zip");
response.addHeader("content-disposition", "attachment;filename=" + zipName);
OutputStream os = response.getOutputStream();
int length = is.read(buffer);
while (length != -1)
{
os.write(buffer, 0, length);
length = is.read(buffer);
}
Here are examples how easily files can be appended to existing zip using TrueVFS:
// append a file to archive under different name
TFile.cp(new File("existingFile.txt"), new TFile("archive.zip", "entry.txt"));
// recusively append a dir to the root of archive
TFile src = new TFile("dirPath", "dirName");
src.cp_r(new TFile("archive.zip", src.getName()));
TrueVFS, the successor of TrueZIP, uses Java 7 NIO 2 features under the hood when appropriate but offers much more features like thread-safe async parallel compression.
Beware also that Java 7 ZipFileSystem by default is vulnerable to OutOfMemoryError on huge inputs.
Here is Java 1.7 version of Liam answer which uses try with resources and Apache Commons IO.
The output is written to a new zip file but it can be easily modified to write to the original file.
/**
* Modifies, adds or deletes file(s) from a existing zip file.
*
* #param zipFile the original zip file
* #param newZipFile the destination zip file
* #param filesToAddOrOverwrite the names of the files to add or modify from the original file
* #param filesToAddOrOverwriteInputStreams the input streams containing the content of the files
* to add or modify from the original file
* #param filesToDelete the names of the files to delete from the original file
* #throws IOException if the new file could not be written
*/
public static void modifyZipFile(File zipFile,
File newZipFile,
String[] filesToAddOrOverwrite,
InputStream[] filesToAddOrOverwriteInputStreams,
String[] filesToDelete) throws IOException {
try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(newZipFile))) {
// add existing ZIP entry to output stream
try (ZipInputStream zin = new ZipInputStream(new FileInputStream(zipFile))) {
ZipEntry entry = null;
while ((entry = zin.getNextEntry()) != null) {
String name = entry.getName();
// check if the file should be deleted
if (filesToDelete != null) {
boolean ignoreFile = false;
for (String fileToDelete : filesToDelete) {
if (name.equalsIgnoreCase(fileToDelete)) {
ignoreFile = true;
break;
}
}
if (ignoreFile) {
continue;
}
}
// check if the file should be kept as it is
boolean keepFileUnchanged = true;
if (filesToAddOrOverwrite != null) {
for (String fileToAddOrOverwrite : filesToAddOrOverwrite) {
if (name.equalsIgnoreCase(fileToAddOrOverwrite)) {
keepFileUnchanged = false;
}
}
}
if (keepFileUnchanged) {
// copy the file as it is
out.putNextEntry(new ZipEntry(name));
IOUtils.copy(zin, out);
}
}
}
// add the modified or added files to the zip file
if (filesToAddOrOverwrite != null) {
for (int i = 0; i < filesToAddOrOverwrite.length; i++) {
String fileToAddOrOverwrite = filesToAddOrOverwrite[i];
try (InputStream in = filesToAddOrOverwriteInputStreams[i]) {
out.putNextEntry(new ZipEntry(fileToAddOrOverwrite));
IOUtils.copy(in, out);
out.closeEntry();
}
}
}
}
}
this works 100% , if you dont want to use extra libs ..
1) first, the class that append files to the zip ..
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class AddZip {
public void AddZip() {
}
public void addToZipFile(ZipOutputStream zos, String nombreFileAnadir, String nombreDentroZip) {
FileInputStream fis = null;
try {
if (!new File(nombreFileAnadir).exists()) {//NO EXISTE
System.out.println(" No existe el archivo : " + nombreFileAnadir);return;
}
File file = new File(nombreFileAnadir);
System.out.println(" Generando el archivo '" + nombreFileAnadir + "' al ZIP ");
fis = new FileInputStream(file);
ZipEntry zipEntry = new ZipEntry(nombreDentroZip);
zos.putNextEntry(zipEntry);
byte[] bytes = new byte[1024];
int length;
while ((length = fis.read(bytes)) >= 0) {zos.write(bytes, 0, length);}
zos.closeEntry();
fis.close();
} catch (FileNotFoundException ex ) {
Logger.getLogger(AddZip.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(AddZip.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
2) you can call it in your controller ..
//in the top
try {
fos = new FileOutputStream(rutaZip);
zos = new ZipOutputStream(fos);
} catch (FileNotFoundException ex) {
Logger.getLogger(UtilZip.class.getName()).log(Level.SEVERE, null, ex);
}
...
//inside your method
addZip.addToZipFile(zos, pathFolderFileSystemHD() + itemFoto.getNombre(), "foto/" + itemFoto.getNombre());
Based on the answer given by #sfussenegger above, following code is used to append to a jar file and download it:
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Resource resourceFile = resourceLoader.getResource("WEB-INF/lib/custom.jar");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try (ZipOutputStream zos = new ZipOutputStream(baos, StandardCharsets.ISO_8859_1);) {
try (ZipFile zin = new ZipFile(resourceFile.getFile(), StandardCharsets.ISO_8859_1);) {
zin.stream().forEach((entry) -> {
try {
zos.putNextEntry(entry);
if (!entry.isDirectory()) {
zin.getInputStream(entry).transferTo(zos);
}
zos.closeEntry();
} catch (Exception ex) {
ex.printStackTrace();
}
});
}
/* build file records to be appended */
....
for (FileContents record : records) {
zos.putNextEntry(new ZipEntry(record.getFileName()));
zos.write(record.getBytes());
zos.closeEntry();
}
zos.flush();
}
response.setContentType("application/java-archive");
response.setContentLength(baos.size());
response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"custom.jar\"");
try (BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream())) {
baos.writeTo(out);
}
}
I have a JSP application that allows the user to upload a ZIP file and then the application will read all the files in the ZIP and store them in a MySQL.
Upon advice I decided to use "Zip File System Provider" to handle the ZIP file:
Path zipPath = Paths.get(zipFile.getSubmittedFileName());//returns the path to the ZIP file
FileSystem fs = FileSystems.newFileSystem(zipPath, null);//creates the file system
I tried to traverse it using:
for (FileStore store: fs.getFileStores()) {
System.err.println("Store: " + store.name());
}
However it loops only one time and returns tmp.zipwhich is the entire ZIP. How do I extract the physical image files one by one so I can store them in MySQL.
Here's code that traverses given ZIP file and prints first 16 bytes of each file inside.
Path filePath = Paths.get("somefile.zip");
FileSystem fileSystem = FileSystems.newFileSystem(filePath, null);
byte[] buffer = new byte[16];
Base64.Encoder encoder = Base64.getEncoder();
for (Path rootDirectory : fileSystem.getRootDirectories()) {
Files.walk(rootDirectory).forEach(path -> {
System.out.print(path);
if (Files.isRegularFile(path)) {
System.out.print(" ");
try (InputStream stream = Files.newInputStream(path)) {
int length = stream.read(buffer);
for (int i = 0; i < length; i++) {
byte b = buffer[i];
if (32 <= b && b < 127) {
System.out.print((char) b);
} else {
System.out.printf("\\%02x", b);
}
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
System.out.println();
});
}
The Apache Commons Compress module probably can help you to iterate through the files.
Below is a sample extract that can iterate over multiple files and extract the byte contents
Sample
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class ZipTest {
public static void main(String[] args) throws FileNotFoundException, IOException {
String fileName = "C:\\temp\\ECDS-File-Upload-Processed.zip";
String destinationDir = "C:\\temp\\mango";
ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(fileName));
ZipEntry zipEntry = zipInputStream.getNextEntry();
byte[] buffer = new byte[1024];
while (zipEntry != null) {
String zipFileName = zipEntry.getName();
File extractedFile = new File(destinationDir + File.separator + zipFileName);
new File(extractedFile.getParent()).mkdirs();
FileOutputStream fos = new FileOutputStream(extractedFile);
int len;
while ((len = zipInputStream.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
fos.close();
zipEntry = zipInputStream.getNextEntry();
}
zipInputStream.closeEntry();
zipInputStream.close();
}
}
I'm having the problem of replacing or updating some files within a certain directory inside a jar file.
I've read a few post already. The code (the JarUpdater Class) given at this link Updating .JAR's contents from code
is being very helpful for me to understand the role and the use of ZipInputStream, ZipOutputStream and ZipEntry, etc..
However, when I run it,
I have an EOF Exception
[EDITED by mk7: I found out the jar file was corrupted after I went through it 20 times or so. So after I replaced the jar file with a new one, the EOF Exception went away. The other two problems below still remains unsolved]
these two new xml files only get copied to the "root directory" of the jar file.
these two new xml files NEVER replaced the two original files inside a directory called /conf.
Which lines of code should I change in order to replace the xml files with the new ones?
With the System.out.println, I did see that the while loop steps through every directory and compare at every file as expected. A new temp jar was also created as expected...
I thought the statement "notInFiles = false" would take care of my need but it's NOT.
How do I step into the /conf and only replace those two files and NOT leave a copy at the root of the jar file?
What am I missing? Thanks for any insight!
Below are the code from that link.
import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
public class JarUpdater {
public static void main(String[] args) {
File[] contents = {new File("abc.xml"),
new File("def.xml")};
File jarFile = new File("xyz.jar");
try {
updateZipFile(jarFile, contents);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void updateZipFile(File jarFile,
File[] contents) throws IOException {
// get a temp file
File tempFile = File.createTempFile(jarFile.getName(), null);
// delete it, otherwise you cannot rename your existing zip to it.
tempFile.delete();
System.out.println("tempFile is " + tempFile);
boolean renameOk=jarFile.renameTo(tempFile);
if (!renameOk)
{
throw new RuntimeException("could not rename the file "+jarFile.getAbsolutePath()+" to "+tempFile.getAbsolutePath());
}
byte[] buf = new byte[1024];
ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile));
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(jarFile));
ZipEntry entry = zin.getNextEntry();
while (entry != null) {
String name = entry.getName();
boolean notInFiles = true;
for (File f : contents) {
System.out.println("f is " + f);
if (f.getName().equals(name)) {
// that file is already inside the jar file
notInFiles = false;
System.out.println("file already inside the jar file");
break;
}
}
if (notInFiles) {
System.out.println("name is " + name);
System.out.println("entry is " + entry);
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(name));
// Transfer bytes from the ZIP file to the output file
int len;
while ((len = zin.read(buf)) > 0) {
out.write(buf, 0, len);
}
}
entry = zin.getNextEntry();
}
// Close the streams
zin.close();
// Compress the contents
for (int i = 0; i < contents.length; i++) {
InputStream in = new FileInputStream(contents[i]);
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(contents[i].getName()));
// Transfer bytes from the file to the ZIP file
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
// Complete the entry
out.closeEntry();
in.close();
}
// Complete the ZIP file
out.close();
tempFile.delete();
}
}
In your first cycle (while loop) where you copy the entries which you don't want to replace you don't close the entries in the output zip file. Add out.closeEntry(); like this:
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(name));
// Transfer bytes from the ZIP file to the output file
int len;
while ((len = zin.read(buf)) > 0) {
out.write(buf, 0, len);
}
// ADD THIS LINE:
out.closeEntry();
Also when you check if an entry is to be replaced, you should compare it to a full path, not just to the name of the file. For example if you want to replace abc.xml which is in the /conf folder, you should compare the entry name to "/conf/abc.xml" and not to "abc.xml".
To properly check if an entry is to be replaced:
String name = entry.getName();
boolean notInFiles = true;
for (File f : contents) {
System.out.println("f is " + f);
if (name.equals("/conf/" + f.getName()) {
// that file is already inside the jar file
notInFiles = false;
System.out.println("file already inside the jar file");
break;
}
}
And when you add the entries to the output which are the replaced files, you also have to specify the entry name having full path, e.g. "/conf/abc.xml" and not just "abc.xml" because it would put "abc.xml" in the root of the output zip.
To do this, start the entry name with "/conf/" like this:
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry("/conf/" + contents[i].getName()));
For URIs with the protocol jar:file: (usable for all zip files), you can use a zip file system.
URI jarUri = new URI("jar:" + jarFile.toURI().toString()); // "jar:file:/C:/../xyz.jar"
Map<String, String> zipProperties = new HashMap<>();
zipProperties.put("encoding", "UTF-8");
try (FileSystem zipFS = FileSystems.newFileSystem(jarUri, zipProperties)) {
for (File file : contents) {
Path updatePath = zipFS.getPath("/" + file.getName());
Files.delete(updatePath);
Files.copy(file.toPath(), updatePath, StandardCopyOption.REPLACE_EXISTING);
}
} // closes.
One way to derive the URI is prefixing "jar:" to a File.toURI().
This is a bit more elegant and abstract, and also allows Files.copy in and out the zip. Something to keep in ones tool chest.
I have tried multiple ways to create this zip file in Java/Groovy. The first couple methods I attempted, from various blogs/postings, resulted in corrupt zip files which could not be opened. So, I tried this one (below) which looked fairly promising. The sysouts report valid file paths being passed to the FileInputStream. I am not sure if it is the FQ path being passed to the ZipOutputStream which is causing the problem. Either way, below is the code, which results in small (188kb) zip file (with no entries) being created. Any suggestions?
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Set;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
class FileZipper {
public static void makeZip(Set fullyQualifiedFileNames, String zipFileName, String outDir) throws IOException, FileNotFoundException
{
// These are the files to include in the ZIP file
Object[] filenames = fullyQualifiedFileNames.toArray();
String fileSeparator = (String) System.getProperties().get("file.separator");
// Create a buffer for reading the files
byte[] buf = new byte[1024];
// Create the ZIP file
String outFilename = outDir + fileSeparator +zipFileName;
FileOutputStream fos = new FileOutputStream(outFilename);
ZipOutputStream zos = new ZipOutputStream(fos);
System.out.println("Zipping to file " +outFilename);
// Compress the files
for (Object fileName: filenames)
{
System.out.println("Adding file: " + fileName);
FileInputStream fis = new FileInputStream((String)fileName);
// Add ZIP entry to output stream.
String[] nodes = ((String)fileName).split("[/[\\\\]]");
String zipEntry = nodes[nodes.length-1];
System.out.println("Adding Zip Entry: " + zipEntry);
zos.putNextEntry(new ZipEntry((String)fileName));
// Transfer bytes from the file to the ZIP file
int len;
int totalBytes = 0;
while ((len = fis.read(buf)) > 0)
{
totalBytes += len;
zos.write(buf, 0, len);
}
System.out.println("Zipped " +totalBytes +" bytes");
// Complete the entry
zos.closeEntry();
fis.close();
}
// Complete the ZIP file
zos.close();
fos.close();
}
}
If you are using Groovy, the easiest way is using AntBuilder:
new AntBuilder().zip(
destfile: "myfile.zip",
basedir: "baseDir")
or as of Groovy 1.8:
ant.zip(destfile: 'file.zip', basedir: 'src_dir')
Have you tried closing the underlying FileOutputStream explicitly to ensure that all data has been flushed to disk?
FileOutputStream fos = new FileOutputStream(outFilename);
ZipOutputStream zos = new ZipOutputStream(fos);
...
zos.Close();
fos.Close();
I ran your code locally and had no problems creating and then opening a zip file.
However, I sometimes used to run into odd issues with the default Java compression utilities, so I started using the Apache Commons compression and have used it since with little difficulty.
Check http://commons.apache.org/compress/index.html for the basic overview, and http://commons.apache.org/compress/examples.html for specific examples.