安卓解压文件

Posted 2022-10-15 呼啸

主要就是采用流的方式处理大文件

1.先将源文件转换成安卓系统自带CheckedInputStream,这个是一个检验流：

 CheckedInputStream cis = new CheckedInputStream(new FileInputStream(srcFile), new CRC32());

2.再将这个检验流转换成Zip输入流：

ZipInputStream zis = new ZipInputStream(cis);

3.获取zip流的实体：

while ((zipEntry = zis.getNextEntry()) != null)

4.然后用字节输出流的方式：

BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));
        int len;
        byte[] buff = new byte[DEFAULT_BUFF_SIZE];
        while ((len = zis.read(buff, 0 ,DEFAULT_BUFF_SIZE)) != -1) 
            bos.write(buff, 0, len);
        

完整代码：

 public static File decompress(File srcFile, File destFile) throws Exception 
        while (destFile.exists()) 
            destFile = new File(destFile.getAbsolutePath()+"1");
        
        CheckedInputStream cis = new CheckedInputStream(new FileInputStream(srcFile), new CRC32());
        ZipInputStream zis = new ZipInputStream(cis);
        doDecompress(destFile, zis);
        zis.close();
        return destFile;
    

    private static void doDecompress(File destFile, ZipInputStream zis) throws Exception 
        ZipEntry zipEntry = null;
        while ((zipEntry = zis.getNextEntry()) != null) 
            String dir = destFile.getPath() + File.separator + zipEntry.getName();
            File dirFile = new File(dir);
            fileProber(dirFile);
            if (zipEntry.isDirectory()) 
                dirFile.mkdirs();
             else 
                doDecompressFile(dirFile, zis);
            
            zis.closeEntry();
        
    

    private static void doDecompressFile(File destFile, ZipInputStream zis) throws Exception 
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));
        int len;
        byte[] buff = new byte[DEFAULT_BUFF_SIZE];
        while ((len = zis.read(buff, 0 ,DEFAULT_BUFF_SIZE)) != -1) 
            bos.write(buff, 0, len);
        
        bos.close();