Package org.apache.commons.compress.archivers.zip

Class ZipUtil

java.lang.Object

org.apache.commons.compress.archivers.zip.ZipUtil

public abstract class ZipUtil
extends Object

Utility class for handling DOS and Java time conversions.

This class is immutable

Constructor Summary

Constructors

Constructor	Description
ZipUtil()

Method Summary

Modifier and Type	Method	Description
static long	adjustToLong(int i)	Assumes a negative integer really is a positive integer that has wrapped around and re-creates the original value.
static long	dosToJavaTime(long dosTime)	Converts DOS time to Java time (number of milliseconds since epoch).
static Date	fromDosTime(ZipLong zipDosTime)	Convert a DOS date/time field to a Date object.
static byte[]	reverse(byte[] array)	Reverses a byte[] array.
static int	signedByteToUnsignedInt(byte b)	Converts a signed byte into an unsigned integer representation (e.g., -1 becomes 255).
static byte[]	toDosTime(long t)	Convert a Date object to a DOS date/time field.
static void	toDosTime(long t, byte[] buf, int offset)	Convert a Date object to a DOS date/time field.
static ZipLong	toDosTime(Date time)	Convert a Date object to a DOS date/time field.
static byte	unsignedIntToSignedByte(int i)	Converts an unsigned integer to a signed byte (e.g., 255 becomes -1).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ZipUtil

public ZipUtil()

Method Detail

toDosTime

public static ZipLong toDosTime(Date time)

Convert a Date object to a DOS date/time field.

Parameters:

time - the Date to convert

Returns:

the date as a ZipLong

toDosTime

public static byte[] toDosTime(long t)

Convert a Date object to a DOS date/time field.

Stolen from InfoZip's fileio.c

Parameters:

t - number of milliseconds since the epoch

Returns:

the date as a byte array

toDosTime

public static void toDosTime(long t,
                             byte[] buf,
                             int offset)

Convert a Date object to a DOS date/time field.

Stolen from InfoZip's fileio.c

Parameters:

t - number of milliseconds since the epoch

buf - the output buffer

offset - The offset within the output buffer of the first byte to be written. must be non-negative and no larger than buf.length-4

adjustToLong

public static long adjustToLong(int i)

Assumes a negative integer really is a positive integer that has wrapped around and re-creates the original value.

Parameters:

i - the value to treat as unsigned int.

Returns:

the unsigned int as a long.

reverse

public static byte[] reverse(byte[] array)

Reverses a byte[] array. Reverses in-place (thus provided array is mutated), but also returns same for convenience.

Parameters:

array - to reverse (mutated in-place, but also returned for convenience).

Returns:

the reversed array (mutated in-place, but also returned for convenience).

Since:

1.5

signedByteToUnsignedInt

public static int signedByteToUnsignedInt(byte b)

Converts a signed byte into an unsigned integer representation (e.g., -1 becomes 255).

Parameters:

b - byte to convert to int

Returns:

int representation of the provided byte

Since:

1.5

unsignedIntToSignedByte

public static byte unsignedIntToSignedByte(int i)

Converts an unsigned integer to a signed byte (e.g., 255 becomes -1).

Parameters:

i - integer to convert to byte

Returns:

byte representation of the provided int

Throws:

IllegalArgumentException - if the provided integer is not inside the range [0,255].

Since:

1.5

fromDosTime

public static Date fromDosTime(ZipLong zipDosTime)

Convert a DOS date/time field to a Date object.

Parameters:

zipDosTime - contains the stored DOS time.

Returns:

a Date instance corresponding to the given time.

dosToJavaTime

public static long dosToJavaTime(long dosTime)

Converts DOS time to Java time (number of milliseconds since epoch).

Parameters:

dosTime - time to convert

Returns:

converted time