Java 如何在 Android 中以编程方式解压缩文件？

How to unzip files programmatically in Android?

提问by Kartik

I need a small code snippet which unzips a few files from a given .zip file and gives the separate files according to the format they were in the zipped file. Please post your knowledge and help me out.

我需要一个小代码片段，它从给定的 .zip 文件中解压缩一些文件，并根据它们在压缩文件中的格式给出单独的文件。请发布您的知识并帮助我。

回答by ankitjaininfo

Android has build-in Java API. Check out java.util.zippackage.

Android 有内置的 Java API。查看java.util.zip包。

The class ZipInputStreamis what you should look into. Read ZipEntry from the ZipInputStream and dump it into filesystem/folder. Check similar example to compress into zipfile.

您应该研究ZipInputStream类。从 ZipInputStream 读取 ZipEntry 并将其转储到文件系统/文件夹中。检查类似的示例以压缩为 zip文件。

回答by petrnohejl

This is my unzip method, which I use:

这是我使用的解压缩方法：

private boolean unpackZip(String path, String zipname)
{       
     InputStream is;
     ZipInputStream zis;
     try 
     {
         is = new FileInputStream(path + zipname);
         zis = new ZipInputStream(new BufferedInputStream(is));          
         ZipEntry ze;

         while((ze = zis.getNextEntry()) != null) 
         {
             ByteArrayOutputStream baos = new ByteArrayOutputStream();
             byte[] buffer = new byte[1024];
             int count;

             String filename = ze.getName();
             FileOutputStream fout = new FileOutputStream(path + filename);

             // reading and writing
             while((count = zis.read(buffer)) != -1) 
             {
                 baos.write(buffer, 0, count);
                 byte[] bytes = baos.toByteArray();
                 fout.write(bytes);             
                 baos.reset();
             }

             fout.close();               
             zis.closeEntry();
         }

         zis.close();
     } 
     catch(IOException e)
     {
         e.printStackTrace();
         return false;
     }

    return true;
}

回答by Renaud

Here is a ZipFileIterator (like a java Iterator, but for zip files):

这是一个 ZipFileIterator（类似于 java 迭代器，但用于 zip 文件）：

package ch.epfl.bbp.io;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class ZipFileIterator implements Iterator<File> {

    private byte[] buffer = new byte[1024];

    private FileInputStream is;
    private ZipInputStream zis;
    private ZipEntry ze;

    public ZipFileIterator(File file) throws FileNotFoundException {
    is = new FileInputStream(file);
    zis = new ZipInputStream(new BufferedInputStream(is));
    }

    @Override
    public boolean hasNext() {
    try {
        return (ze = zis.getNextEntry()) != null;
    } catch (IOException e) {
        e.printStackTrace();
    }
    return false;
    }

    @Override
    public File next() {
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int count;

        String filename = ze.getName();
        File tmpFile = File.createTempFile(filename, "tmp");
        tmpFile.deleteOnExit();// TODO make it configurable
        FileOutputStream fout = new FileOutputStream(tmpFile);

        while ((count = zis.read(buffer)) != -1) {
        baos.write(buffer, 0, count);
        byte[] bytes = baos.toByteArray();
        fout.write(bytes);
        baos.reset();
        }
        fout.close();
        zis.closeEntry();

        return tmpFile;

    } catch (Exception e) {
        throw new RuntimeException(e);
    }
    }

    @Override
    public void remove() {
    throw new RuntimeException("not implemented");
    }

    public void close() {
    try {
        zis.close();
        is.close();
    } catch (IOException e) {// nope
    }
    }
}

回答by Vasily Sochinsky

Had peno's version optimised a bit. The increase in performance is perceptible.

对 peno 的版本进行了一些优化。性能的提升是显而易见的。

private boolean unpackZip(String path, String zipname)
{       
     InputStream is;
     ZipInputStream zis;
     try 
     {
         String filename;
         is = new FileInputStream(path + zipname);
         zis = new ZipInputStream(new BufferedInputStream(is));          
         ZipEntry ze;
         byte[] buffer = new byte[1024];
         int count;

         while ((ze = zis.getNextEntry()) != null) 
         {
             filename = ze.getName();

             // Need to create directories if not exists, or
             // it will generate an Exception...
             if (ze.isDirectory()) {
                File fmd = new File(path + filename);
                fmd.mkdirs();
                continue;
             }

             FileOutputStream fout = new FileOutputStream(path + filename);

             while ((count = zis.read(buffer)) != -1) 
             {
                 fout.write(buffer, 0, count);             
             }

             fout.close();               
             zis.closeEntry();
         }

         zis.close();
     } 
     catch(IOException e)
     {
         e.printStackTrace();
         return false;
     }

    return true;
}

回答by jcw

While the answers that are already here work well, I found that they were slightly slower than I had hoped for. Instead I used zip4j, which I think is the best solution because of its speed. It also allowed for different options for the amount of compression, which I found useful.

虽然这里的答案效果很好，但我发现它们比我希望的要慢一些。相反，我使用了zip4j，我认为这是最好的解决方案，因为它的速度。它还允许压缩量的不同选项，我发现这很有用。

回答by userDroid

public class MainActivity extends Activity {

private String LOG_TAG = MainActivity.class.getSimpleName();

private File zipFile;
private File destination;

private TextView status;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    status = (TextView) findViewById(R.id.main_status);
    status.setGravity(Gravity.CENTER);

    if ( initialize() ) {
        zipFile = new File(destination, "BlueBoxnew.zip");
        try {
            Unzipper.unzip(zipFile, destination);
            status.setText("Extracted to \n"+destination.getAbsolutePath());
        } catch (ZipException e) {
            Log.e(LOG_TAG, e.getMessage());
        } catch (IOException e) {
            Log.e(LOG_TAG, e.getMessage());
        }
    } else {
        status.setText("Unable to initialize sd card.");
    }
}

public boolean initialize() {
    boolean result = false;
     File sdCard = new File(Environment.getExternalStorageDirectory()+"/zip/");
    //File sdCard = Environment.getExternalStorageDirectory();
    if ( sdCard != null ) {
        destination = sdCard;
        if ( !destination.exists() ) {
            if ( destination.mkdir() ) {
                result = true;
            }
        } else {
            result = true;
        }
    }

    return result;
}

 }

->Helper Class(Unzipper.java)

->Helper 类(Unzipper.java)

    import java.io.File;
    import java.io.FileInputStream;
   import java.io.FileOutputStream;
    import java.io.IOException;
       import java.util.zip.ZipEntry;
    import java.util.zip.ZipException;
    import java.util.zip.ZipInputStream;
     import android.util.Log;

   public class Unzipper {

private static String LOG_TAG = Unzipper.class.getSimpleName();

public static void unzip(final File file, final File destination) throws ZipException, IOException {
    new Thread() {
        public void run() {
            long START_TIME = System.currentTimeMillis();
            long FINISH_TIME = 0;
            long ELAPSED_TIME = 0;
            try {
                ZipInputStream zin = new ZipInputStream(new FileInputStream(file));
                String workingDir = destination.getAbsolutePath()+"/";

                byte buffer[] = new byte[4096];
                int bytesRead;
                ZipEntry entry = null;
                while ((entry = zin.getNextEntry()) != null) {
                    if (entry.isDirectory()) {
                        File dir = new File(workingDir, entry.getName());
                        if (!dir.exists()) {
                            dir.mkdir();
                        }
                        Log.i(LOG_TAG, "[DIR] "+entry.getName());
                    } else {
                        FileOutputStream fos = new FileOutputStream(workingDir + entry.getName());
                        while ((bytesRead = zin.read(buffer)) != -1) {
                            fos.write(buffer, 0, bytesRead);
                        }
                        fos.close();
                        Log.i(LOG_TAG, "[FILE] "+entry.getName());
                    }
                }
                zin.close();

                FINISH_TIME = System.currentTimeMillis();
                ELAPSED_TIME = FINISH_TIME - START_TIME;
                Log.i(LOG_TAG, "COMPLETED in "+(ELAPSED_TIME/1000)+" seconds.");
            } catch (Exception e) {
                Log.e(LOG_TAG, "FAILED");
            }
        };
    }.start();
}

   }

->xml layout(activity_main.xml):

-> xml 布局（activity_main.xml）：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity" >

<TextView
    android:id="@+id/main_status"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world" />

</RelativeLayout>

->permission in Menifest file:

-> 在 Menifest 文件中的权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

回答by zapl

Based on Vasily Sochinsky's answer a bit tweaked & with a small fix:

基于 Vasily Sochinsky 的回答，稍作调整并进行了小修正：

public static void unzip(File zipFile, File targetDirectory) throws IOException {
    ZipInputStream zis = new ZipInputStream(
            new BufferedInputStream(new FileInputStream(zipFile)));
    try {
        ZipEntry ze;
        int count;
        byte[] buffer = new byte[8192];
        while ((ze = zis.getNextEntry()) != null) {
            File file = new File(targetDirectory, ze.getName());
            File dir = ze.isDirectory() ? file : file.getParentFile();
            if (!dir.isDirectory() && !dir.mkdirs())
                throw new FileNotFoundException("Failed to ensure directory: " +
                        dir.getAbsolutePath());
            if (ze.isDirectory())
                continue;
            FileOutputStream fout = new FileOutputStream(file);
            try {
                while ((count = zis.read(buffer)) != -1)
                    fout.write(buffer, 0, count);
            } finally {
                fout.close();
            }
            /* if time should be restored as well
            long time = ze.getTime();
            if (time > 0)
                file.setLastModified(time);
            */
        }
    } finally {
        zis.close();
    }
}

Notable differences

显着差异

• public static- this is a static utility method that can be anywhere.
• 2 Fileparameters because Stringare :/ for files and one could not specify where the zip file is to be extracted before. Also path + filenameconcatenation > https://stackoverflow.com/a/412495/995891
• throws- because catch late- add a try catch if really not interested in them.
• actually makes sure that the required directories exist in all cases. Not every zip contains all the required directory entries in advance of file entries. This had 2 potential bugs:
  • if the zip contains an empty directory and instead of the resulting directory there is an existing file, this was ignored. The return value of mkdirs()is important.
  • could crash on zip files that don't contain directories.
• increased write buffer size, this should improve performance a bit. Storage is usually in 4k blocks and writing in smaller chunks is usually slower than necessary.
• uses the magic of finallyto prevent resource leaks.

• public static- 这是一个可以在任何地方使用的静态实用方法。
• 2 个File参数因为String是 :/ 用于文件，一个无法指定之前要提取 zip 文件的位置。还path + filename串联 > https://stackoverflow.com/a/412495/995891
• throws- 因为捕获晚了- 如果真的对它们不感兴趣，请添加一个尝试捕获。
• 实际上确保在所有情况下都存在所需的目录。并非每个 zip 在文件条目之前都包含所有必需的目录条目。这有两个潜在的错误：
  • 如果 zip 包含一个空目录，并且存在一个现有文件而不是生成的目录，则忽略该文件。的返回值mkdirs()很重要。
  • 可能会在不包含目录的 zip 文件上崩溃。
• 增加写入缓冲区大小，这应该会稍微提高性能。存储通常以 4k 块为单位，以较小的块写入通常比必要的要慢。
• 使用魔法finally来防止资源泄漏。

So

所以

unzip(new File("/sdcard/pictures.zip"), new File("/sdcard"));

should do the equivalent of the original

应该做相当于原来的

unpackZip("/sdcard/", "pictures.zip")

回答by Behrouz.M

According to @zapl answer,Unzip with progress report:

根据@zapl 的回答，解压进度报告：

public interface UnzipFile_Progress
{
    void Progress(int percent, String FileName);
}

// unzip(new File("/sdcard/pictures.zip"), new File("/sdcard"));
public static void UnzipFile(File zipFile, File targetDirectory, UnzipFile_Progress progress) throws IOException,
        FileNotFoundException
{
    long total_len = zipFile.length();
    long total_installed_len = 0;

    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(new FileInputStream(zipFile)));
    try
    {
        ZipEntry ze;
        int count;
        byte[] buffer = new byte[1024];
        while ((ze = zis.getNextEntry()) != null)
        {
            if (progress != null)
            {
                total_installed_len += ze.getCompressedSize();
                String file_name = ze.getName();
                int percent = (int)(total_installed_len * 100 / total_len);
                progress.Progress(percent, file_name);
            }

            File file = new File(targetDirectory, ze.getName());
            File dir = ze.isDirectory() ? file : file.getParentFile();
            if (!dir.isDirectory() && !dir.mkdirs())
                throw new FileNotFoundException("Failed to ensure directory: " + dir.getAbsolutePath());
            if (ze.isDirectory())
                continue;
            FileOutputStream fout = new FileOutputStream(file);
            try
            {
                while ((count = zis.read(buffer)) != -1)
                    fout.write(buffer, 0, count);
            } finally
            {
                fout.close();
            }

            // if time should be restored as well
            long time = ze.getTime();
            if (time > 0)
                file.setLastModified(time);
        }
    } finally
    {
        zis.close();
    }
}

回答by Manohar Reddy

UPDATE 2016 use the following class

UPDATE 2016 使用以下类

    package com.example.zip;

    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipInputStream;
    import android.util.Log;

    public class DecompressFast {



 private String _zipFile; 
  private String _location; 

  public DecompressFast(String zipFile, String location) { 
    _zipFile = zipFile; 
    _location = location; 

    _dirChecker(""); 
  } 

  public void unzip() { 
    try  { 
      FileInputStream fin = new FileInputStream(_zipFile); 
      ZipInputStream zin = new ZipInputStream(fin); 
      ZipEntry ze = null; 
      while ((ze = zin.getNextEntry()) != null) { 
        Log.v("Decompress", "Unzipping " + ze.getName()); 

        if(ze.isDirectory()) { 
          _dirChecker(ze.getName()); 
        } else { 
          FileOutputStream fout = new FileOutputStream(_location + ze.getName()); 
         BufferedOutputStream bufout = new BufferedOutputStream(fout);
          byte[] buffer = new byte[1024];
          int read = 0;
          while ((read = zin.read(buffer)) != -1) {
              bufout.write(buffer, 0, read);
          }




          bufout.close();

          zin.closeEntry(); 
          fout.close(); 
        } 

      } 
      zin.close(); 


      Log.d("Unzip", "Unzipping complete. path :  " +_location );
    } catch(Exception e) { 
      Log.e("Decompress", "unzip", e); 

      Log.d("Unzip", "Unzipping failed");
    } 

  } 

  private void _dirChecker(String dir) { 
    File f = new File(_location + dir); 

    if(!f.isDirectory()) { 
      f.mkdirs(); 
    } 
  } 


 }

How to use

如何使用

 String zipFile = Environment.getExternalStorageDirectory() + "/the_raven.zip"; //your zip file location
    String unzipLocation = Environment.getExternalStorageDirectory() + "/unzippedtestNew/"; // destination folder location
  DecompressFast df= new DecompressFast(zipFile, unzipLocation);
    df.unzip();

Permissions

权限

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

回答by nilsi

Minimal example I used to unzip a specific file from my zipfile into my applications cache folder. I then read the manifest file using a different method.

我曾经将特定文件从 zipfile 解压缩到我的应用程序缓存文件夹中的最小示例。然后我使用不同的方法读取清单文件。

private void unzipUpdateToCache() {
    ZipInputStream zipIs = new ZipInputStream(context.getResources().openRawResource(R.raw.update));
    ZipEntry ze = null;

    try {

        while ((ze = zipIs.getNextEntry()) != null) {
            if (ze.getName().equals("update/manifest.json")) {
                FileOutputStream fout = new FileOutputStream(context.getCacheDir().getAbsolutePath() + "/manifest.json");

                byte[] buffer = new byte[1024];
                int length = 0;

                while ((length = zipIs.read(buffer))>0) {
                    fout.write(buffer, 0, length);
                }
                zipIs .closeEntry();
                fout.close();
            }
        }
        zipIs .close();

    } catch (IOException e) {
        e.printStackTrace();
    }

}