/**
* ZipExtraField related methods
- *
+ *
*/
public class ExtraFieldUtils {
- /**
- * Static registry of known extra fields.
- *
- * @since 1.1
- */
- private static Hashtable implementations;
+ /**
+ * Static registry of known extra fields.
+ *
+ * @since 1.1
+ */
+ private static Hashtable implementations;
+
+ static {
+ implementations = new Hashtable();
+ register(AsiExtraField.class);
+ register(JarMarker.class);
+ }
- static {
- implementations = new Hashtable();
- register(AsiExtraField.class);
- register(JarMarker.class);
+ /**
+ * Register a ZipExtraField implementation.
+ *
+ * <p>
+ * The given class must have a no-arg constructor and implement the
+ * {@link ZipExtraField ZipExtraField interface}.
+ * </p>
+ *
+ * @param c
+ * the class to register
+ *
+ * @since 1.1
+ */
+ public static void register(Class c) {
+ try {
+ ZipExtraField ze = (ZipExtraField) c.newInstance();
+ implementations.put(ze.getHeaderId(), c);
+ } catch (ClassCastException cc) {
+ throw new RuntimeException(c + " doesn\'t implement ZipExtraField");
+ } catch (InstantiationException ie) {
+ throw new RuntimeException(c + " is not a concrete class");
+ } catch (IllegalAccessException ie) {
+ throw new RuntimeException(c + "\'s no-arg constructor is not public");
}
+ }
- /**
- * Register a ZipExtraField implementation.
- *
- * <p>The given class must have a no-arg constructor and implement
- * the {@link ZipExtraField ZipExtraField interface}.</p>
- * @param c the class to register
- *
- * @since 1.1
- */
- public static void register(Class c) {
- try {
- ZipExtraField ze = (ZipExtraField) c.newInstance();
- implementations.put(ze.getHeaderId(), c);
- } catch (ClassCastException cc) {
- throw new RuntimeException(c + " doesn\'t implement ZipExtraField");
- } catch (InstantiationException ie) {
- throw new RuntimeException(c + " is not a concrete class");
- } catch (IllegalAccessException ie) {
- throw new RuntimeException(c + "\'s no-arg constructor is not public");
- }
+ /**
+ * Create an instance of the approriate ExtraField, falls back to
+ * {@link UnrecognizedExtraField UnrecognizedExtraField}.
+ *
+ * @param headerId
+ * the header identifier
+ * @return an instance of the appropiate ExtraField
+ * @exception InstantiationException
+ * if unable to instantiate the class
+ * @exception IllegalAccessException
+ * if not allowed to instatiate the class
+ * @since 1.1
+ */
+ public static ZipExtraField createExtraField(ZipShort headerId)
+ throws InstantiationException, IllegalAccessException {
+ Class c = (Class) implementations.get(headerId);
+ if (c != null) {
+ return (ZipExtraField) c.newInstance();
}
+ UnrecognizedExtraField u = new UnrecognizedExtraField();
+ u.setHeaderId(headerId);
+ return u;
+ }
- /**
- * Create an instance of the approriate ExtraField, falls back to
- * {@link UnrecognizedExtraField UnrecognizedExtraField}.
- * @param headerId the header identifier
- * @return an instance of the appropiate ExtraField
- * @exception InstantiationException if unable to instantiate the class
- * @exception IllegalAccessException if not allowed to instatiate the class
- * @since 1.1
- */
- public static ZipExtraField createExtraField(ZipShort headerId)
- throws InstantiationException, IllegalAccessException {
- Class c = (Class) implementations.get(headerId);
- if (c != null) {
- return (ZipExtraField) c.newInstance();
- }
- UnrecognizedExtraField u = new UnrecognizedExtraField();
- u.setHeaderId(headerId);
- return u;
+ /**
+ * Split the array into ExtraFields and populate them with the give data.
+ *
+ * @param data
+ * an array of bytes
+ * @return an array of ExtraFields
+ * @since 1.1
+ * @throws ZipException
+ * on error
+ */
+ public static ZipExtraField[] parse(byte[] data) throws ZipException {
+ Vector v = new Vector();
+ int start = 0;
+ while (start <= data.length - 4) {
+ ZipShort headerId = new ZipShort(data, start);
+ int length = (new ZipShort(data, start + 2)).getValue();
+ if (start + 4 + length > data.length) {
+ throw new ZipException("data starting at " + start
+ + " is in unknown format");
+ }
+ try {
+ ZipExtraField ze = createExtraField(headerId);
+ ze.parseFromLocalFileData(data, start + 4, length);
+ v.addElement(ze);
+ } catch (InstantiationException ie) {
+ throw new ZipException(ie.getMessage());
+ } catch (IllegalAccessException iae) {
+ throw new ZipException(iae.getMessage());
+ }
+ start += (length + 4);
+ }
+ if (start != data.length) { // array not exhausted
+ throw new ZipException("data starting at " + start
+ + " is in unknown format");
}
- /**
- * Split the array into ExtraFields and populate them with the
- * give data.
- * @param data an array of bytes
- * @return an array of ExtraFields
- * @since 1.1
- * @throws ZipException on error
- */
- public static ZipExtraField[] parse(byte[] data) throws ZipException {
- Vector v = new Vector();
- int start = 0;
- while (start <= data.length - 4) {
- ZipShort headerId = new ZipShort(data, start);
- int length = (new ZipShort(data, start + 2)).getValue();
- if (start + 4 + length > data.length) {
- throw new ZipException("data starting at " + start
- + " is in unknown format");
- }
- try {
- ZipExtraField ze = createExtraField(headerId);
- ze.parseFromLocalFileData(data, start + 4, length);
- v.addElement(ze);
- } catch (InstantiationException ie) {
- throw new ZipException(ie.getMessage());
- } catch (IllegalAccessException iae) {
- throw new ZipException(iae.getMessage());
- }
- start += (length + 4);
- }
- if (start != data.length) { // array not exhausted
- throw new ZipException("data starting at " + start
- + " is in unknown format");
- }
+ ZipExtraField[] result = new ZipExtraField[v.size()];
+ v.copyInto(result);
+ return result;
+ }
- ZipExtraField[] result = new ZipExtraField[v.size()];
- v.copyInto(result);
- return result;
+ /**
+ * Merges the local file data fields of the given ZipExtraFields.
+ *
+ * @param data
+ * an array of ExtraFiles
+ * @return an array of bytes
+ * @since 1.1
+ */
+ public static byte[] mergeLocalFileDataData(ZipExtraField[] data) {
+ int sum = 4 * data.length;
+ for (int i = 0; i < data.length; i++) {
+ sum += data[i].getLocalFileDataLength().getValue();
}
-
- /**
- * Merges the local file data fields of the given ZipExtraFields.
- * @param data an array of ExtraFiles
- * @return an array of bytes
- * @since 1.1
- */
- public static byte[] mergeLocalFileDataData(ZipExtraField[] data) {
- int sum = 4 * data.length;
- for (int i = 0; i < data.length; i++) {
- sum += data[i].getLocalFileDataLength().getValue();
- }
- byte[] result = new byte[sum];
- int start = 0;
- for (int i = 0; i < data.length; i++) {
- System.arraycopy(data[i].getHeaderId().getBytes(),
- 0, result, start, 2);
- System.arraycopy(data[i].getLocalFileDataLength().getBytes(),
- 0, result, start + 2, 2);
- byte[] local = data[i].getLocalFileDataData();
- System.arraycopy(local, 0, result, start + 4, local.length);
- start += (local.length + 4);
- }
- return result;
+ byte[] result = new byte[sum];
+ int start = 0;
+ for (int i = 0; i < data.length; i++) {
+ System.arraycopy(data[i].getHeaderId().getBytes(), 0, result, start, 2);
+ System.arraycopy(data[i].getLocalFileDataLength().getBytes(), 0, result,
+ start + 2, 2);
+ byte[] local = data[i].getLocalFileDataData();
+ System.arraycopy(local, 0, result, start + 4, local.length);
+ start += (local.length + 4);
}
+ return result;
+ }
- /**
- * Merges the central directory fields of the given ZipExtraFields.
- * @param data an array of ExtraFields
- * @return an array of bytes
- * @since 1.1
- */
- public static byte[] mergeCentralDirectoryData(ZipExtraField[] data) {
- int sum = 4 * data.length;
- for (int i = 0; i < data.length; i++) {
- sum += data[i].getCentralDirectoryLength().getValue();
- }
- byte[] result = new byte[sum];
- int start = 0;
- for (int i = 0; i < data.length; i++) {
- System.arraycopy(data[i].getHeaderId().getBytes(),
- 0, result, start, 2);
- System.arraycopy(data[i].getCentralDirectoryLength().getBytes(),
- 0, result, start + 2, 2);
- byte[] local = data[i].getCentralDirectoryData();
- System.arraycopy(local, 0, result, start + 4, local.length);
- start += (local.length + 4);
- }
- return result;
+ /**
+ * Merges the central directory fields of the given ZipExtraFields.
+ *
+ * @param data
+ * an array of ExtraFields
+ * @return an array of bytes
+ * @since 1.1
+ */
+ public static byte[] mergeCentralDirectoryData(ZipExtraField[] data) {
+ int sum = 4 * data.length;
+ for (int i = 0; i < data.length; i++) {
+ sum += data[i].getCentralDirectoryLength().getValue();
+ }
+ byte[] result = new byte[sum];
+ int start = 0;
+ for (int i = 0; i < data.length; i++) {
+ System.arraycopy(data[i].getHeaderId().getBytes(), 0, result, start, 2);
+ System.arraycopy(data[i].getCentralDirectoryLength().getBytes(), 0,
+ result, start + 2, 2);
+ byte[] local = data[i].getCentralDirectoryData();
+ System.arraycopy(local, 0, result, start + 4, local.length);
+ start += (local.length + 4);
}
+ return result;
+ }
}