ZipInputStream.java [plain text]
package java.util.zip;
import java.io.EOFException;
import java.io.InputStream;
import java.io.IOException;
public class ZipInputStream extends InflaterInputStream implements ZipConstants
{
private CRC32 crc = new CRC32();
private ZipEntry entry = null;
private int csize;
private int size;
private int method;
private int flags;
private int avail;
private boolean entryAtEOF;
public ZipInputStream(InputStream in)
{
super(in, new Inflater(true));
}
private void fillBuf() throws IOException
{
avail = len = in.read(buf, 0, buf.length);
}
private int readBuf(byte[] out, int offset, int length) throws IOException
{
if (avail <= 0)
{
fillBuf();
if (avail <= 0)
return -1;
}
if (length > avail)
length = avail;
System.arraycopy(buf, len - avail, out, offset, length);
avail -= length;
return length;
}
private void readFully(byte[] out) throws IOException
{
int off = 0;
int len = out.length;
while (len > 0)
{
int count = readBuf(out, off, len);
if (count == -1)
throw new EOFException();
off += count;
len -= count;
}
}
private final int readLeByte() throws IOException
{
if (avail <= 0)
{
fillBuf();
if (avail <= 0)
throw new ZipException("EOF in header");
}
return buf[len - avail--] & 0xff;
}
private final int readLeShort() throws IOException
{
return readLeByte() | (readLeByte() << 8);
}
private final int readLeInt() throws IOException
{
return readLeShort() | (readLeShort() << 16);
}
public ZipEntry getNextEntry() throws IOException
{
if (crc == null)
throw new IOException("Stream closed.");
if (entry != null)
closeEntry();
int header = readLeInt();
if (header == CENSIG)
{
close();
return null;
}
if (header != LOCSIG)
throw new ZipException("Wrong Local header signature: "
+ Integer.toHexString(header));
readLeShort();
flags = readLeShort();
method = readLeShort();
int dostime = readLeInt();
int crc = readLeInt();
csize = readLeInt();
size = readLeInt();
int nameLen = readLeShort();
int extraLen = readLeShort();
if (method == ZipOutputStream.STORED && csize != size)
throw new ZipException("Stored, but compressed != uncompressed");
byte[] buffer = new byte[nameLen];
readFully(buffer);
String name = new String(buffer);
entry = createZipEntry(name);
entryAtEOF = false;
entry.setMethod(method);
if ((flags & 8) == 0)
{
entry.setCrc(crc & 0xffffffffL);
entry.setSize(size & 0xffffffffL);
entry.setCompressedSize(csize & 0xffffffffL);
}
entry.setDOSTime(dostime);
if (extraLen > 0)
{
byte[] extra = new byte[extraLen];
readFully(extra);
entry.setExtra(extra);
}
if (method == ZipOutputStream.DEFLATED && avail > 0)
{
System.arraycopy(buf, len - avail, buf, 0, avail);
len = avail;
avail = 0;
inf.setInput(buf, 0, len);
}
return entry;
}
private void readDataDescr() throws IOException
{
if (readLeInt() != EXTSIG)
throw new ZipException("Data descriptor signature not found");
entry.setCrc(readLeInt() & 0xffffffffL);
csize = readLeInt();
size = readLeInt();
entry.setSize(size & 0xffffffffL);
entry.setCompressedSize(csize & 0xffffffffL);
}
public void closeEntry() throws IOException
{
if (crc == null)
throw new IOException("Stream closed.");
if (entry == null)
return;
if (method == ZipOutputStream.DEFLATED)
{
if ((flags & 8) != 0)
{
byte[] tmp = new byte[2048];
while (read(tmp) > 0)
;
return;
}
csize -= inf.getTotalIn();
avail = inf.getRemaining();
}
if (avail > csize && csize >= 0)
avail -= csize;
else
{
csize -= avail;
avail = 0;
while (csize != 0)
{
long skipped = in.skip(csize & 0xffffffffL);
if (skipped <= 0)
throw new ZipException("zip archive ends early.");
csize -= skipped;
}
}
size = 0;
crc.reset();
if (method == ZipOutputStream.DEFLATED)
inf.reset();
entry = null;
entryAtEOF = true;
}
public int available() throws IOException
{
return entryAtEOF ? 0 : 1;
}
public int read() throws IOException
{
byte[] b = new byte[1];
if (read(b, 0, 1) <= 0)
return -1;
return b[0] & 0xff;
}
public int read(byte[] b, int off, int len) throws IOException
{
if (len == 0)
return 0;
if (crc == null)
throw new IOException("Stream closed.");
if (entry == null)
return -1;
boolean finished = false;
switch (method)
{
case ZipOutputStream.DEFLATED:
len = super.read(b, off, len);
if (len < 0)
{
if (!inf.finished())
throw new ZipException("Inflater not finished!?");
avail = inf.getRemaining();
if ((flags & 8) != 0)
readDataDescr();
if (inf.getTotalIn() != csize
|| inf.getTotalOut() != size)
throw new ZipException("size mismatch: "+csize+";"+size+" <-> "+inf.getTotalIn()+";"+inf.getTotalOut());
inf.reset();
finished = true;
}
break;
case ZipOutputStream.STORED:
if (len > csize && csize >= 0)
len = csize;
len = readBuf(b, off, len);
if (len > 0)
{
csize -= len;
size -= len;
}
if (csize == 0)
finished = true;
else if (len < 0)
throw new ZipException("EOF in stored block");
break;
}
if (len > 0)
crc.update(b, off, len);
if (finished)
{
if ((crc.getValue() & 0xffffffffL) != entry.getCrc())
throw new ZipException("CRC mismatch");
crc.reset();
entry = null;
entryAtEOF = true;
}
return len;
}
public void close() throws IOException
{
super.close();
crc = null;
entry = null;
entryAtEOF = true;
}
protected ZipEntry createZipEntry(String name)
{
return new ZipEntry(name);
}
}