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提供单独的文件。请发布您的知识并帮助我。
答案 0 :(得分：131)
如果Peno的版本有所优化。性能的提高是可感知的。
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;
}
答案 1 :(得分：89)
基于瓦西里·索辛斯基的回答有点调整＆amp;小修：
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();
}
}
显着差异
public static - 这是一个静态的实用工具方法，可以在任何地方。File个参数，因为String是：/用于文件，而且无法指定之前提取zip文件的位置。另外path + filename串联＆gt; https://stackoverflow.com/a/412495/995891 throws - 因为catch late - 添加一个try catch如果真的对它们不感兴趣。mkdirs()的返回值非常重要。finally的魔力来防止资源泄漏。所以
unzip(new File("/sdcard/pictures.zip"), new File("/sdcard"));
应该相当于原来的
unpackZip("/sdcard/", "pictures.zip")
答案 2 :(得分：23)
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;
}
答案 3 :(得分：13)
Android内置了Java API。查看java.util.zip包。
课程ZipInputStream是你应该研究的。从ZipInputStream中读取ZipEntry并将其转储到filesystem /文件夹中。检查similar example to compress into zip文件。
答案 4 :(得分：5)
虽然已经在这里的答案运作良好，但我发现它们比我希望的稍慢。相反，我使用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，我发现它很有用。
答案 5 :(得分：5)
根据@zapl的回答，解压缩进度报告：
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();
}
}
答案 6 :(得分：5)
2016年更新 使用以下课程
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();
}
}
}
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();
权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
答案 7 :(得分：4)
科特林方式
//FileExt.kt
data class ZipIO (val entry: ZipEntry, val output: File)
fun File.unzip(unzipLocationRoot: File? = null) {
val rootFolder = unzipLocationRoot ?: File(parentFile.absolutePath + File.separator + nameWithoutExtension)
if (!rootFolder.exists()) {
rootFolder.mkdirs()
}
ZipFile(this).use { zip ->
zip
.entries()
.asSequence()
.map {
val outputFile = File(rootFolder.absolutePath + File.separator + it.name)
ZipIO(it, outputFile)
}
.map {
it.output.parentFile?.run{
if (!exists()) mkdirs()
}
it
}
.filter { !it.entry.isDirectory }
.forEach { (entry, output) ->
zip.getInputStream(entry).use { input ->
output.outputStream().use { output ->
input.copyTo(output)
}
}
}
}
}
用法
val zipFile = File("path_to_your_zip_file")
file.unzip()
答案 8 :(得分：3)
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;
}
}
- ＆gt; Helper Class（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();
}
}
- ＆gt; xml layout（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>
- ＆gt; Menifest文件中的权限：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
答案 9 :(得分：2)
这是一个ZipFileIterator（就像java Iterator，但是对于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
}
}
}
答案 10 :(得分：2)
最小的例子我曾经将我的zipfile中的特定文件解压缩到我的应用程序缓存文件夹中。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();
}
}
答案 11 :(得分：2)
我正在使用Java的ZipFile类无法处理的zip文件。 Java 8显然无法处理压缩方法12（我相信bzip2）。尝试了多种方法（包括zip4j）（由于另一个问题，该方法在某些特定文件中也失败）后，我成功使用了支持additional compression methods as mentioned here的 Apache的commons-compress 。
请注意，下面的ZipFile类不是java.util.zip中的类。
它实际上是 org.apache.commons.compress.archivers.zip.ZipFile ，因此请小心导入。
try (ZipFile zipFile = new ZipFile(archiveFile)) {
Enumeration<ZipArchiveEntry> entries = zipFile.getEntries();
while (entries.hasMoreElements()) {
ZipArchiveEntry entry = entries.nextElement();
File entryDestination = new File(destination, entry.getName());
if (entry.isDirectory()) {
entryDestination.mkdirs();
} else {
entryDestination.getParentFile().mkdirs();
try (InputStream in = zipFile.getInputStream(entry); OutputStream out = new FileOutputStream(entryDestination)) {
IOUtils.copy(in, out);
}
}
}
} catch (IOException ex) {
log.debug("Error unzipping archive file: " + archiveFile, ex);
}
对于Gradle：
compile 'org.apache.commons:commons-compress:1.18'
答案 12 :(得分：1)
受密码保护的Zip文件
如果你想用密码压缩文件，你可以看看this library，它可以轻松地用密码压缩文件：
<强>邮编：
ZipArchive zipArchive = new ZipArchive();
zipArchive.zip(targetPath,destinationPath,password);
<强>解压缩：
ZipArchive zipArchive = new ZipArchive();
zipArchive.unzip(targetPath,destinationPath,password);
<强>的RAR：
RarArchive rarArchive = new RarArchive();
rarArchive.extractArchive(file archive, file destination);
这个库的文档已经足够好了，我刚从那里添加了几个例子。 它是完全免费的，专门为Android而写。
答案 13 :(得分：1)
根据zapl的回答，在try()的结尾处添加Closeable会在使用后自动关闭流。
public static void unzip(File zipFile, File targetDirectory) {
try (FileInputStream fis = new FileInputStream(zipFile)) {
try (BufferedInputStream bis = new BufferedInputStream(fis)) {
try (ZipInputStream zis = new ZipInputStream(bis)) {
ZipEntry ze;
int count;
byte[] buffer = new byte[Constant.DefaultBufferSize];
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;
try (FileOutputStream fout = new FileOutputStream(file)) {
while ((count = zis.read(buffer)) != -1)
fout.write(buffer, 0, count);
}
}
}
}
} catch (Exception ex) {
//handle exception
}
}
使用Constant.DefaultBufferSize Stream.CopyTo中的65536（C# .NET 4），是乔恩·斯凯特（Jon Skeet）在这里给出的答案：
https://stackoverflow.com/a/411605/1876355
我总是看到使用byte[1024]或byte[4096]缓冲区的帖子，却不知道它可以更大，从而提高了性能，并且仍然可以正常工作。
这是Stream源代码：
https://referencesource.microsoft.com/#mscorlib/system/io/stream.cs
//We pick a value that is the largest multiple of 4096 that is still smaller than the large object heap threshold (85K). // The CopyTo/CopyToAsync buffer is short-lived and is likely to be collected at Gen0, and it offers a significant // improvement in Copy performance. private const int _DefaultCopyBufferSize = 81920;
但是，为了安全起见，我将其拨回了65536的倍数，4096。