JAVA中压缩与解压缩

以压缩Zip文件为例。主要是通过ZipOutputStream类实现。解压缩主要使用ZipFile类和ZipInputStream以及ZipEntry类。

package main;

import java.io.*;
import java.util.*;
import java.util.zip.*;
public class Main
{

public static final Integer BUFFERSIZE = 1024*1024;
public static void main(String[] args) throws Exception
{
File fileNeedToBeCompressed = new File("C:" + File.separator + "D" + File.separator + "code" + File.separator + "output.xml");
StringBuffer zipFilePath = new StringBuffer(fileNeedToBeCompressed.getParent());
zipFilePath.append(File.separator).append(getFileName(fileNeedToBeCompressed.getName())).append(".zip");
File compressedFile = new File(zipFilePath.toString());

InputStream is = null;
ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(compressedFile));

if(fileNeedToBeCompressed.isDirectory())
{
//压缩一个文件夹

File[] files = fileNeedToBeCompressed.listFiles();
for(File file : files)
{
compressFile(file, is, zos);
}
}
else
{
//压缩一个文件

compressFile(fileNeedToBeCompressed,is,zos);
}
zos.close();

System.out.println("///~ Main done");
}

public static String getFileName(String fileName)
{
if(fileName.lastIndexOf('.') < 0)
{
return fileName;
}
else
{
return fileName.substring(0,fileName.lastIndexOf('.'));
}
}

public static void compressFile(File fileNeedToBeCompressed,InputStream is,ZipOutputStream zos) throws Exception
{
System.out.println("正在压缩:" + fileNeedToBeCompressed.getName());
is = new FileInputStream(fileNeedToBeCompressed);
zos.putNextEntry(new ZipEntry(fileNeedToBeCompressed.getName()));
int bytesReaded = 0;
byte[] buffer = new byte[BUFFERSIZE];
while((bytesReaded = is.read(buffer)) > 0)
{
zos.write(buffer,0,bytesReaded);
}
is.close();
}

}

ZipInputStream 获取压缩文件中的每个ZipEntry，然后ZipFile通过ZipEntry拿到输入流。

package main;

import java.io.*;
import java.util.*;
import java.util.zip.*;
public class Main
{

public static final Integer BUFFERSIZE = 1024*1024;
public static void main(String[] args) throws Exception
{
//        {
//            File fileNeedToBeCompressed = new File("C:" + File.separator + "D" + File.separator + "code" + File.separator + "resource");
//            StringBuffer zipFilePath = new StringBuffer(fileNeedToBeCompressed.getParent());
//            zipFilePath.append(File.separator).append(getFileName(fileNeedToBeCompressed.getName())).append(".zip");
//            File compressedFile = new File(zipFilePath.toString());
//
//
//            InputStream is = null;
//            ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(compressedFile));
//
//            if(fileNeedToBeCompressed.isDirectory())
//            {
//                //压缩一个文件夹
//                File[] files = fileNeedToBeCompressed.listFiles();
//                for(File file : files)
//                {
//                    compressFile(file, is, zos);
//                }
//            }
//            else
//            {
//                //压缩一个文件
//
//                compressFile(fileNeedToBeCompressed,is,zos);
//            }
//            zos.close();
//        }

{
String zipFilePath = "C:" + File.separator + "D" + File.separator + "code" + File.separator + "resource.zip";
ZipFile zipFile = new ZipFile(zipFilePath);
ZipInputStream zis = new ZipInputStream(new FileInputStream(new File(zipFilePath)));
ZipEntry tempZipEntry = null;
OutputStream os = null;
byte[] buffer = new byte[BUFFERSIZE];
File unzipedFolder = new File(getFileName(zipFile.getName()));
int bytesReaded = 0;
if(!unzipedFolder.exists())
unzipedFolder.mkdirs();
while((tempZipEntry = zis.getNextEntry())!= null)
{
System.out.println("正在解压:" + tempZipEntry.getName());
File newFile = new File(unzipedFolder.getPath() + File.separator + tempZipEntry.getName());
InputStream is = zipFile.getInputStream(tempZipEntry);
os = new FileOutputStream(newFile);
while(( bytesReaded = is.read(buffer)) > 0)
{
os.write(buffer, 0, bytesReaded);
}
os.close();
}
zipFile.close();
zis.close();
}
System.out.println("///~ Main done");
}

public static String getFileName(String fileName)
{
if(fileName.lastIndexOf('.') < 0)
{
return fileName;
}
else
{
return fileName.substring(0,fileName.lastIndexOf('.'));
}
}

public static void compressFile(File fileNeedToBeCompressed,InputStream is,ZipOutputStream zos) throws Exception
{
System.out.println("正在压缩:" + fileNeedToBeCompressed.getName());
is = new FileInputStream(fileNeedToBeCompressed);
zos.putNextEntry(new ZipEntry(fileNeedToBeCompressed.getName()));
int bytesReaded = 0;
byte[] buffer = new byte[BUFFERSIZE];
while((bytesReaded = is.read(buffer)) > 0)
{
zos.write(buffer,0,bytesReaded);
}
is.close();
}

}