public byte[] getBytes() throws HeaderException {
try {
int length =
HEADER_LENGTH
+ (scopeInformationElements.size() * InformationElement.LENGTH)
+ (informationElements.size() * InformationElement.LENGTH);
if (length % 4 != 0) {
length += (length % 4); // padding
}
byte[] data = new byte[length];
// template ID
System.arraycopy(Shorts.toByteArray((short) getTemplateID()), 0, data, 0, 2);
// field count
System.arraycopy(Shorts.toByteArray((short) getFieldCount()), 0, data, 2, 2);
// scope field count
System.arraycopy(Shorts.toByteArray((short) getScopeFieldCount()), 0, data, 4, 2);
// information elements
int offset = HEADER_LENGTH;
for (InformationElement ie : scopeInformationElements) {
System.arraycopy(ie.getBytes(), 0, data, offset, InformationElement.LENGTH);
offset += InformationElement.LENGTH;
}
for (InformationElement ie : informationElements) {
System.arraycopy(ie.getBytes(), 0, data, offset, InformationElement.LENGTH);
offset += InformationElement.LENGTH;
}
return data;
} catch (Exception e) {
throw new HeaderException("Error while generating the bytes: " + e.getMessage());
}
}
public List<InformationElement> getElements(ElementId elementId) {
ArrayList<InformationElement> ret = new ArrayList<InformationElement>();
for (InformationElement element : elements)
if (element.getElementId() == elementId) ret.add(element);
return ret;
}
public static OptionTemplateRecord parse(byte[] data) throws HeaderException {
try {
if (data.length < HEADER_LENGTH) {
throw new HeaderException("Data array too short.");
}
OptionTemplateRecord otr = new OptionTemplateRecord();
// template ID
byte[] templateID = new byte[2];
System.arraycopy(data, 0, templateID, 0, 2);
otr.setTemplateID(Ints.fromByteArray(templateID));
// field count
byte[] fieldCount = new byte[2];
System.arraycopy(data, 2, fieldCount, 0, 2);
otr.setFieldCount(Ints.fromByteArray(fieldCount));
// scope field count
byte[] scopeFieldCount = new byte[2];
System.arraycopy(data, 4, scopeFieldCount, 0, 2);
otr.setScopeFieldCount(Ints.fromByteArray(scopeFieldCount));
int offset = HEADER_LENGTH;
for (int i = 0; i < otr.getFieldCount(); i++) {
byte[] subData = new byte[InformationElement.LENGTH];
System.arraycopy(
data, offset + (i * InformationElement.LENGTH), subData, 0, InformationElement.LENGTH);
InformationElement ie = InformationElement.parse(subData);
if (i < otr.getScopeFieldCount()) {
otr.getScopeInformationElements().add(ie);
} else {
otr.getInformationElements().add(ie);
}
}
return otr;
} catch (Exception e) {
throw new HeaderException("Parse error: " + e.getMessage());
}
}
public void replaceElement(InformationElement element) {
// Remove any elements with the same element ID
for (int i = 0; i < elements.size(); i++)
if (elements.get(i).getElementId() == element.getElementId()) {
elements.remove(i);
i--;
}
// Add the new created element
elements.add(element);
}
public InformationElement getElement(ElementId elementId) {
for (InformationElement element : elements)
if (element.getElementId() == elementId) return element;
return null;
}
