在Android中以编程方式解压缩文件 [英] Unzipping files programmatically in Android
问题描述
我正在下载一个zip文件夹并保存在我的Android设备的特定文件夹中。我的应用程序没有访问该文件夹，因为它是压缩的。我想从服务器下载后解压缩文件夹并保存在特定文件夹中。
I am downloading a zip folder and saving in specific folder in my Android device. My application is not accessing the folder as it is zipped. I would like to unzip the folder after downloading from server and save in specific folder.
我的代码在这里：
public void DownloadDatabase(String DownloadUrl, String fileName) {
try {
File root = android.os.Environment.getExternalStorageDirectory();
File dir = new File(root.getAbsolutePath() + "/timy/databases");
if(dir.exists() == false){
dir.mkdirs();
}
URL url = new URL("http://myexample.com/android/timy.zip");
File file = new File(dir,fileName);
long startTime = System.currentTimeMillis();
Log.d("DownloadManager" , "download url:" +url);
Log.d("DownloadManager" , "download file name:" + fileName);
URLConnection uconn = url.openConnection();
uconn.setConnectTimeout(TIMEOUT_SOCKET);
InputStream is = uconn.getInputStream();
ZipInputStream zipinstream = new ZipInputStream(new BufferedInputStream(is));
ZipEntry zipEntry;
while((zipEntry = zipinstream.getNextEntry()) != null){
String zipEntryName = zipEntry.getName();
File file1 = new File(file + zipEntryName);
if(file1.exists()){
}else{
if(zipEntry.isDirectory()){
file1.mkdirs();
}
}
}
BufferedInputStream bufferinstream = new BufferedInputStream(is);
ByteArrayBuffer baf = new ByteArrayBuffer(5000);
int current = 0;
while((current = bufferinstream.read()) != -1){
baf.append((byte) current);
}
FileOutputStream fos = new FileOutputStream( file);
fos.write(baf.toByteArray());
fos.flush();
fos.close();
Log.d("DownloadManager" , "download ready in" + ((System.currentTimeMillis() - startTime)/1000) + "sec");
}
catch(IOException e) {
Log.d("DownloadManager" , "Error:" + e);
e.printStackTrace();
}
}
我的logcat显示错误。 Just folder正在我的设备中创建，没有文件正在下载并解压缩。不使用inputZipStream方法，我的压缩文件夹正在下载并保存在SD卡中。当我想解压缩它时，它不会发生。
And my logcat is showing on error. Just folder is creating in my device and no files are downloading with unzipped. Without using inputZipStream method then my zipped folder is downloading and saving in sdcard. When I want to unzip it, it is not happening.
推荐答案
这篇文章是关于如何编写实用程序类来提取文件压缩zip存档中的目录和内容，使用内置Java API。
This article is about how to write a utility class for extracting files and directories in a compressed zip archive, using built-in Java API.
java.util.zip包提供以下类，用于从ZIP存档中提取文件和目录：
The java.util.zip package provides the following classes for extracting files and directories from a ZIP archive:
ZipInputStream：这是主类，可用于读取zip文件并提取存档中的文件和目录（条目）。以下是此类的一些重要用法：
-read通过其构造函数ZipInputStream（FileInputStream）读取
-read文件和目录条目通过方法getNextEntry（）
-read当前二进制数据通过方法读取（字节）
- 通过方法关闭当前条目closeEntry（）
- 通过方法关闭zip文件close（）
ZipInputStream: this is the main class which can be used for reading zip file and extracting files and directories (entries) within the archive. Here are some important usages of this class: -read a zip via its constructor ZipInputStream(FileInputStream) -read entries of files and directories via method getNextEntry() -read binary data of current entry via method read(byte) -close current entry via method closeEntry() -close the zip file via method close()
ZipEntry ：此类表示zip文件中的条目。每个文件或目录都表示为ZipEntry对象。它的方法getName（）返回一个String，它表示文件/目录的路径。路径采用以下形式：
folder_1 / subfolder_1 / subfolder_2 / ... / subfolder_n / file.ext
ZipEntry: this class represents an entry in the zip file. Each file or directory is represented as a ZipEntry object. Its method getName() returns a String which represents path of the file/directory. The path is in the following form: folder_1/subfolder_1/subfolder_2/…/subfolder_n/file.ext
根据ZipEntry的路径，我们重新 - 解压缩zip文件时创建目录结构。
Based on the path of a ZipEntry, we re-create directory structure when extracting the zip file.
下面的类用于解压缩下载zip文件并提取文件并存储你想要的位置。
Below class is used for unzip download zip and extract file and store your desire location.
public class UnzipUtil
{
private String zipFile;
private String location;
public UnzipUtil(String zipFile, String location)
{
this.zipFile = zipFile;
this.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());
byte[] buffer = new byte[8192];
int len;
while ((len = zin.read(buffer)) != -1)
{
fout.write(buffer, 0, len);
}
fout.close();
zin.closeEntry();
}
}
zin.close();
}
catch(Exception e)
{
Log.e("Decompress", "unzip", e);
}
}
private void dirChecker(String dir)
{
File f = new File(location + dir);
if(!f.isDirectory())
{
f.mkdirs();
}
}
}
MainActivity.Class：
MainActivity.Class:
public class MainActivity extends Activity
{
private ProgressDialog mProgressDialog;
String Url="http://hasmukh/hb.zip";
String unzipLocation = Environment.getExternalStorageDirectory() + "/unzipFolder/";
String StorezipFileLocation =Environment.getExternalStorageDirectory() + "/DownloadedZip";
String DirectoryName=Environment.getExternalStorageDirectory() + "/unzipFolder/files/";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
DownloadZipfile mew = new DownloadZipfile();
mew.execute(url);
}
//-This is method is used for Download Zip file from server and store in Desire location.
class DownloadZipfile extends AsyncTask<String, String, String>
{
String result ="";
@Override
protected void onPreExecute()
{
super.onPreExecute();
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setMessage("Downloading...");
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setCancelable(false);
mProgressDialog.show();
}
@Override
protected String doInBackground(String... aurl)
{
int count;
try
{
URL url = new URL(aurl[0]);
URLConnection conexion = url.openConnection();
conexion.connect();
int lenghtOfFile = conexion.getContentLength();
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(StorezipFileLocation);
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1)
{
total += count;
publishProgress(""+(int)((total*100)/lenghtOfFile));
output.write(data, 0, count);
}
output.close();
input.close();
result = "true";
} catch (Exception e) {
result = "false";
}
return null;
}
protected void onProgressUpdate(String... progress)
{
Log.d("ANDRO_ASYNC",progress[0]);
mProgressDialog.setProgress(Integer.parseInt(progress[0]));
}
@Override
protected void onPostExecute(String unused)
{
mProgressDialog.dismiss();
if(result.equalsIgnoreCase("true"))
{
try
{
unzip();
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else
{
}
}
}
//This is the method for unzip file which is store your location. And unzip folder will store as per your desire location.
public void unzip() throws IOException
{
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setMessage("Please Wait...");
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setCancelable(false);
mProgressDialog.show();
new UnZipTask().execute(StorezipFileLocation, DirectoryName);
}
private class UnZipTask extends AsyncTask<String, Void, Boolean>
{
@SuppressWarnings("rawtypes")
@Override
protected Boolean doInBackground(String... params)
{
String filePath = params[0];
String destinationPath = params[1];
File archive = new File(filePath);
try
{
ZipFile zipfile = new ZipFile(archive);
for (Enumeration e = zipfile.entries(); e.hasMoreElements();)
{
ZipEntry entry = (ZipEntry) e.nextElement();
unzipEntry(zipfile, entry, destinationPath);
}
UnzipUtil d = new UnzipUtil(StorezipFileLocation, DirectoryName);
d.unzip();
}
catch (Exception e)
{
return false;
}
return true;
}
@Override
protected void onPostExecute(Boolean result)
{
mProgressDialog.dismiss();
}
private void unzipEntry(ZipFile zipfile, ZipEntry entry,String outputDir) throws IOException
{
if (entry.isDirectory())
{
createDir(new File(outputDir, entry.getName()));
return;
}
File outputFile = new File(outputDir, entry.getName());
if (!outputFile.getParentFile().exists())
{
createDir(outputFile.getParentFile());
}
// Log.v("", "Extracting: " + entry);
BufferedInputStream inputStream = new BufferedInputStream(zipfile.getInputStream(entry));
BufferedOutputStream outputStream = new BufferedOutputStream(new FileOutputStream(outputFile));
try
{
}
finally
{
outputStream.flush();
outputStream.close();
inputStream.close();
}
}
private void createDir(File dir)
{
if (dir.exists())
{
return;
}
if (!dir.mkdirs())
{
throw new RuntimeException("Can not create dir " + dir);
}
}}
}
Note: Do not forgot to add below permission in android Manifest.xml file.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" ></uses-permission>
<uses-permission android:name="android.permission.INTERNET" />
这篇关于在Android中以编程方式解压缩文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
