How to create a zip file in Java

Question

I have a dynamic text file that picks content from a database according to the user s query  I have to write this content into a text file and zip it in a folder in a servlet  How should I do this

User · Answer

If you want decompress without software better use this code  Other code with pdf files sends error on manually decompress   byte   buffer   new byte 1024            try                  FileOutputStream fos   new FileOutputStream  123 zip            ZipOutputStream zos   new ZipOutputStream fos           ZipEntry ze  new ZipEntry  file pdf            zos putNextEntry ze           FileInputStream in   new FileInputStream  file pdf            int len          while   len   in read buffer    gt  0                         zos write buffer  0  len                     in close            zos closeEntry            zos close              catch IOException ex               ex printStackTrace

User · Answer

This is how you create a zip file from a source file   String srcFilename    C  myfile txt   String zipFile    C  myfile zip    try       byte   buffer   new byte 1024       FileOutputStream fos   new FileOutputStream zipFile       ZipOutputStream zos   new ZipOutputStream fos                File srcFile   new File srcFilename       FileInputStream fis   new FileInputStream srcFile       zos putNextEntry new ZipEntry srcFile getName                    int length      while   length   fis read buffer    gt  0            zos write buffer  0  length             zos closeEntry        fis close        zos close                  catch  IOException ioe        System out println  Error creating zip file    ioe

User · Answer

You have mainly to create two functions  First is writeToZipFile   and second is createZipfileForOutPut      and then call the createZipfileForOutPut  file name of  zip          public static void writeToZipFile String path  ZipOutputStream zipStream          throws FileNotFoundException  IOException        System out println  Writing file        path      to zip file         File aFile   new File path       FileInputStream fis   new FileInputStream aFile       ZipEntry zipEntry   new ZipEntry path       zipStream putNextEntry zipEntry        byte   bytes   new byte 1024       int length      while   length   fis read bytes    gt   0            zipStream write bytes  0  length              zipStream closeEntry        fis close       public static void createZipfileForOutPut String filename        String home   System getProperty  user home          File directory   new File home     Documents      AutomationReport        File directory   new File  AutomationReport        if   directory exists              directory mkdir              try           FileOutputStream fos   new FileOutputStream  Path to your destination    filename     zip            ZipOutputStream zos   new ZipOutputStream fos            writeToZipFile  Path to file which you want to compress   zip   zos             zos close            fos close          catch  FileNotFoundException e            e printStackTrace          catch  IOException e            e printStackTrace

User · Answer

Here is an example code to compress a Whole Directory including sub files and sub directories   it s using the walk file tree feature of Java NIO   import java io FileOutputStream  import java io IOException  import java nio file    import java nio file attribute BasicFileAttributes  import java util zip ZipEntry  import java util zip ZipOutputStream   public class ZipCompress       public static void compress String dirPath            final Path sourceDir   Paths get dirPath           String zipFileName   dirPath concat   zip            try               final ZipOutputStream outputStream   new ZipOutputStream new FileOutputStream zipFileName                Files walkFileTree sourceDir  new SimpleFileVisitor lt Path gt                       Override                 public FileVisitResult visitFile Path file  BasicFileAttributes attributes                        try                           Path targetFile   sourceDir relativize file                           outputStream putNextEntry new ZipEntry targetFile toString                              byte   bytes   Files readAllBytes file                           outputStream write bytes  0  bytes length                           outputStream closeEntry                          catch  IOException e                            e printStackTrace                                              return FileVisitResult CONTINUE                                                outputStream close              catch  IOException e                e printStackTrace                        To use this  just call  ZipCompress compress  target directoryToCompress      and you ll get a zip file directoryToCompress zip

User · Answer

Spring boot controller  zip the files in a directory  and can be downloaded    RequestMapping value     files zip    ResponseBody byte   filesZip   throws IOException       File dir   new File            File   filesArray   dir listFiles        if  filesArray    null    filesArray length    0          System out println dir getAbsolutePath       have no file         ByteArrayOutputStream bo   new ByteArrayOutputStream        ZipOutputStream zipOut  new ZipOutputStream bo       for File xlsFile filesArray           if  xlsFile isFile   continue          ZipEntry zipEntry   new ZipEntry xlsFile getName             zipOut putNextEntry zipEntry           zipOut write IOUtils toByteArray new FileInputStream xlsFile             zipOut closeEntry              zipOut close        return bo toByteArray

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Single file   String filePath     absolute path file1 txt   String zipPath     absolute path output zip    try  ZipOutputStream zipOut   new ZipOutputStream new FileOutputStream zipPath          File fileToZip   new File filePath       zipOut putNextEntry new ZipEntry fileToZip getName          Files copy fileToZip toPath    zipOut       Multiple files   List lt String gt  filePaths   Arrays asList   absolute path file1 txt     absolute path file2 txt    String zipPath     absolute path output zip    try  ZipOutputStream zipOut   new ZipOutputStream new FileOutputStream zipPath          for  String filePath   filePaths            File fileToZip   new File filePath           zipOut putNextEntry new ZipEntry fileToZip getName              Files copy fileToZip toPath    zipOut

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There is another option by using zip4j at https   github com srikanth-lingala zip4j  Creating a zip file with single file in it   Adding single file to an existing zip  new ZipFile  filename zip   addFile  filename ext       Or  new ZipFile  filename zip   addFile new File  filename ext      Creating a zip file with multiple files   Adding multiple files to an existing zip  new ZipFile  filename zip   addFiles Arrays asList new File  first file    new File  second file       Creating a zip file by adding a folder to it   Adding a folder to an existing zip  new ZipFile  filename zip   addFolder new File   user myuser folder to add      Creating a zip file from stream   Adding a stream to an existing zip new ZipFile  filename zip   addStream inputStream  new ZipParameters

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public static void zipFromTxt String zipFilePath  String txtFilePath        Assert notNull zipFilePath   Zip file path is required        Assert notNull txtFilePath   Txt file path is required        zipFromTxt new File zipFilePath   new File txtFilePath       public static void zipFromTxt File zipFile  File txtFile        ZipOutputStream out   null      FileInputStream in   null      try           Assert notNull zipFile   Zip file is required            Assert notNull txtFile   Txt file is required            out   new ZipOutputStream new FileOutputStream zipFile            in   new FileInputStream txtFile           out putNextEntry new ZipEntry txtFile getName              int len          byte   buffer   new byte 1024           while   len   in read buffer    gt  0                out write buffer  0  len               out flush                    catch  Exception e            log info  Zip from txt occur error Detail message      e toString           finally           try               if  in    null  in close                if  out    null                    out closeEntry                    out close                            catch  Exception e                log info  Zip from txt close error Detail message      e toString

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public static void main String args          omtZip  res     omt zip      public static void omtZip String path String outputFile        final int BUFFER   2048      boolean isEntry   false      ArrayList lt String gt  directoryList   new ArrayList lt String gt         File f   new File path       if f exists              try               FileOutputStream fos   new FileOutputStream outputFile               ZipOutputStream zos   new ZipOutputStream new BufferedOutputStream fos                byte data     new byte BUFFER                if f isDirectory                                   This is Directory                 do                      String directoryName                           if directoryList size    gt  0                                                directoryName   directoryList get 0                           System out println  Directory Name At 0    directoryName                                             String fullPath   path directoryName                      File fileList   null                      if directoryList size      0                                                  Main path  Root Directory                          fileList   f                       else                                                 Child Directory                         fileList   new File fullPath                                             String   filesName   fileList list                         int totalFiles   filesName length                      for int i   0   i  lt  totalFiles   i                                                  String name   filesName i                           File filesOrDir   new File fullPath name                           if filesOrDir isDirectory                                                          System out println  New Directory Entry    directoryName name                                   ZipEntry entry   new ZipEntry directoryName name                                   zos putNextEntry entry                               isEntry   true                              directoryList add directoryName name                                else                                                       System out println  New File Entry    directoryName name                               ZipEntry entry   new ZipEntry directoryName name                               zos putNextEntry entry                               isEntry   true                              FileInputStream fileInputStream   new FileInputStream filesOrDir                               BufferedInputStream bufferedInputStream   new BufferedInputStream fileInputStream  BUFFER                               int size   -1                              while    size   bufferedInputStream read data  0  BUFFER      -1                                                                  zos write data  0  size                                                             bufferedInputStream close                                                                        if directoryList size    gt  0  amp  amp  directoryName trim   length    gt  0                                                System out println  Directory removed    directoryName                           directoryList remove 0                                           while directoryList size    gt  0                else                                 This is File                   Zip this file                 System out println  Zip this file    f getPath                     FileInputStream fis   new FileInputStream f                   BufferedInputStream bis   new BufferedInputStream fis BUFFER                   ZipEntry entry   new ZipEntry f getName                     zos putNextEntry entry                   isEntry   true                  int size   -1                   while   size   bis read data 0 BUFFER      -1                                        zos write data  0  size                                                                 CHECK IS THERE ANY ENTRY IN ZIP   ----START             if isEntry                              zos close                 else                               zos   null                  System out println  No Entry Found in Zip                                CHECK IS THERE ANY ENTRY IN ZIP   ----START          catch Exception e                        e printStackTrace                   else               System out println  File or Directory not found

User · Answer

Java 7 has ZipFileSystem built in  that can be used to create  write and read file from zip file   Java Doc  ZipFileSystem Provider  Map lt String  String gt  env   new HashMap lt  gt        Create the zip file if it doesn t exist env put  create    true     URI uri   URI create  jar file  codeSamples zipfs zipfstest zip     try  FileSystem zipfs   FileSystems newFileSystem uri  env         Path externalTxtFile   Paths get   codeSamples zipfs SomeTextFile txt        Path pathInZipfile   zipfs getPath   SomeTextFile txt                     Copy a file into the zip file     Files copy externalTxtFile  pathInZipfile  StandardCopyOption REPLACE EXISTING

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Look at this example   StringBuilder sb   new StringBuilder    sb append  Test String     File f   new File  d   test zip    ZipOutputStream out   new ZipOutputStream new FileOutputStream f    ZipEntry e   new ZipEntry  mytext txt    out putNextEntry e    byte   data   sb toString   getBytes    out write data  0  data length   out closeEntry     out close      This will create a zip in the root of D  named test zip which will contain one single file called mytext txt  Of course you can add more zip entries and also specify a subdirectory like this   ZipEntry e   new ZipEntry  folderName mytext txt      You can find more information about compression with Java here

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To write a ZIP file  you use a ZipOutputStream  For each entry that you want to place into the ZIP file  you create a ZipEntry object  You pass the file name to the ZipEntry constructor  it sets the other parameters such as file date and decompression method  You can override these settings if you like  Then  you call the putNextEntry method of the ZipOutputStream to begin writing a new file  Send the file data to the ZIP stream  When you are done  call closeEntry  Repeat for all the files you want to store  Here is a code skeleton   FileOutputStream fout   new FileOutputStream  test zip    ZipOutputStream zout   new ZipOutputStream fout   for all files       ZipEntry ze   new ZipEntry filename       zout putNextEntry ze       send data to zout      zout closeEntry      zout close

User · Answer

Since it took me a while to figure it out  I thought it would be helpful to post my solution using Java 7  ZipFileSystem    openZip runFile     addToZip filepath     loop construct      zipfs close      private void openZip File runFile  throws IOException       Map lt String  String gt  env   new HashMap lt  gt         env put  create    true        env put  encoding    UTF-8        Files deleteIfExists runFile toPath         zipfs   FileSystems newFileSystem URI create  jar     runFile toURI   toString     env            private void addToZip String filename  throws IOException       Path externalTxtFile   Paths get filename  toAbsolutePath        Path pathInZipfile   zipfs getPath filename substring filename lastIndexOf  results        all files to be stored have a common base folder  results  in my case     if  Files isDirectory externalTxtFile             Files createDirectories pathInZipfile           try  DirectoryStream lt Path gt  ds   Files newDirectoryStream externalTxtFile                 for  Path child   ds                    addToZip child normalize   toString       recursive call                               else              copy file to zip file         Files copy externalTxtFile  pathInZipfile  StandardCopyOption REPLACE EXISTING

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Given exportPath and queryResults as String variables  the following block creates a results zip file under exportPath and writes the content of queryResults to a results txt file inside the zip   URI uri   URI create  jar file     exportPath     results zip    Map lt String  String gt  env   Collections singletonMap  create    true     try  FileSystem zipfs   FileSystems newFileSystem uri  env       Path filePath   zipfs getPath   results txt      byte   fileContent   queryResults getBytes       Files write filePath  fileContent  StandardOpenOption CREATE

User · Answer

Using Jeka https   jeka dev JkPathTree  it s quite straightforward   Path wholeDirToZip   Paths get  dir to zip    Path zipFile   Paths get  file zip    JkPathTree of wholeDirToZip  zipTo zipFile

[java] How to create a zip file in Java

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