我使用这样的代码在Android上创建归档文件:
OutputStream os = new FileOutputStream(zipFile);
ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(os));
try
{
zos.setLevel(8);
byte[] buffer = new byte[32768];
for (VFile src : toPack)
{
ZipEntry entry = new ZipEntry(src.name);
zos.putNextEntry(entry);
src.pushToStream(zos, buffer);
src.close();
zos.closeEntry();
}
}
finally
{
zos.close();
}
我发现,只有一种压缩方法可用- DEFLATED
(这里只有STORED
可替代)。 这意味着,归档总是与一个方法压缩。
如果我运行在Android 2.3.4这段代码 - 我可以解压缩在Windows中使用7Zip的文件; 如果我在Android上运行3本(或三星Galaxy Tab,不知道谁做是错误的) - 7Zip的显示存档列表,但无法解压缩文件说不受支持的压缩方法 。 与此同时7Zip的显示放气作为文件的压缩方法,这意味着它能够适当地对待它。
有没有人有这个问题?
谢谢。
UDP:发现了另一个类似的问题主题 (可能是不相同的,虽然)。
该@ user1269737的答案是正确的; 几乎。 但它仅适用于一个单一的文件档案。 下面是解析整个压缩代码。
/**
* Replace wrong local file header byte
* http://sourceforge.net/tracker/?func=detail&aid=3477810&group_id=14481&atid=114481
* Applies to Android API 9-13
* @param zip file
* @throws IOException
*/
private static void fixInvalidZipFile(File zip) throws IOException
{
RandomAccessFile r = new RandomAccessFile(zip, "rw");
try
{
long eocd_offset = findEOCDRecord(r);
if (eocd_offset > 0)
{
r.seek(eocd_offset + 16); // offset of first CDE in EOCD
long cde_offset = readInt(r); // read offset of first Central Directory Entry
long lfh_offset = 0;
long fskip, dskip;
while (true)
{
r.seek(cde_offset);
if (readInt(r) != CDE_SIGNATURE) // got off sync!
return;
r.seek(cde_offset + 20); // compressed file size offset
fskip = readInt(r);
// fix the header
//
r.seek(lfh_offset + 7);
short localFlagsHi = r.readByte(); // hi-order byte of local header flags (general purpose)
r.seek(cde_offset + 9);
short realFlagsHi = r.readByte(); // hi-order byte of central directory flags (general purpose)
if (localFlagsHi != realFlagsHi)
{ // in latest versions this bug is fixed, so we're checking is bug exists.
r.seek(lfh_offset + 7);
r.write(realFlagsHi);
}
// calculate offset of next Central Directory Entry
//
r.seek(cde_offset + 28); // offset of variable CDE parts length in CDE
dskip = 46; // length of fixed CDE part
dskip += readShort(r); // file name
dskip += readShort(r); // extra field
dskip += readShort(r); // file comment
cde_offset += dskip;
if (cde_offset >= eocd_offset) // finished!
break;
// calculate offset of next Local File Header
//
r.seek(lfh_offset + 26); // offset of variable LFH parts length in LFH
fskip += readShort(r); // file name
fskip += readShort(r); // extra field
fskip += 30; // length of fixed LFH part
fskip += 16; // length of Data Descriptor (written after file data)
lfh_offset += fskip;
}
}
}
finally
{
r.close();
}
}
//http://www.pkware.com/documents/casestudies/APPNOTE.TXT
private static final int LFH_SIGNATURE = 0x04034b50;
private static final int DD_SIGNATURE = 0x08074b50;
private static final int CDE_SIGNATURE = 0x02014b50;
private static final int EOCD_SIGNATURE = 0x06054b50;
/** Find an offset of End Of Central Directory record in file */
private static long findEOCDRecord(RandomAccessFile f) throws IOException
{
long result = f.length() - 22; // 22 is minimal EOCD record length
while (result > 0)
{
f.seek(result);
if (readInt(f) == EOCD_SIGNATURE) return result;
result--;
}
return -1;
}
/** Read a 4-byte integer from file converting endianness. */
private static int readInt(RandomAccessFile f) throws IOException
{
int result = 0;
result |= f.read();
result |= (f.read() << 8);
result |= (f.read() << 16);
result |= (f.read() << 24);
return result;
}
/** Read a 2-byte integer from file converting endianness. */
private static short readShort(RandomAccessFile f) throws IOException
{
short result = 0;
result |= f.read();
result |= (f.read() << 8);
return result;
}
需要更新。 它修复单个文件压缩。 你要看看下面的序列中的zip文件{0,0×08,0×08,0×08,0}并且它替换{0,0×08,0×00,0×08,0}
/**
* Replace wrong byte http://sourceforge.net/tracker/?func=detail&aid=3477810&group_id=14481&atid=114481
* @param zip file
* @throws IOException
*/
private static void replaceWrongZipByte(File zip) throws IOException {
RandomAccessFile r = new RandomAccessFile(zip, "rw");
int flag = Integer.parseInt("00001000", 2); //wrong byte
r.seek(7);
int realFlags = r.read();
if( (realFlags & flag) > 0) { // in latest versions this bug is fixed, so we're checking is bug exists.
r.seek(7);
flag = (~flag & 0xff);
// removing only wrong bit, other bits remains the same.
r.write(realFlags & flag);
}
r.close();
}
更新版:
下面的代码将删除ZIP所有错误字节。 KMPMatch.java容易在谷歌找到
public static void replaceWrongBytesInZip(File zip) throws IOException {
byte find[] = new byte[] { 0, 0x08, 0x08, 0x08, 0 };
int index;
while( (index = indexOfBytesInFile(zip,find)) != -1) {
replaceWrongZipByte(zip, index + 2);
}
}
private static int indexOfBytesInFile(File file,byte find[]) throws IOException {
byte fileContent[] = new byte[(int) file.length()];
FileInputStream fin = new FileInputStream(file);
fin.read(fileContent);
fin.close();
return KMPMatch.indexOf(fileContent, find);
}
/**
* Replace wrong byte http://sourceforge.net/tracker/?func=detail&aid=3477810&group_id=14481&atid=114481
* @param zip file
* @throws IOException
*/
private static void replaceWrongZipByte(File zip, int wrongByteIndex) throws IOException {
RandomAccessFile r = new RandomAccessFile(zip, "rw");
int flag = Integer.parseInt("00001000", 2);
r.seek(wrongByteIndex);
int realFlags = r.read();
if( (realFlags & flag) > 0) { // in latest versions this bug is fixed, so we're checking is bug exists.
r.seek(wrongByteIndex);
flag = (~flag & 0xff);
// removing only wrong bit, other bits remains the same.
r.write(realFlags & flag);
}
r.close();
}
文章来源: Cannot extract file from ZIP archive created on Android (device/OS specific)