I have two trees:tree1,tree2 and I want to drag and drop from tree1 to tree2.
The problem is when I want to move a completely folder,his childrens don't take the right place in tree2. They are just added in tree2 but don't get their true parent (the folder that I dragged).In fact I didn't find how to know the new id of the folder in tree2.
Here is my code :
private void Drag() {
tree1().setDragMode(TreeDragMode.NODE);
// Allow all nodes to have children
for (final Object itemId : tree2().getItemIds()) {
tree2().setChildrenAllowed(itemId, true);
}
tree2().setDragMode(TreeDragMode.NODE);
tree2().setDropHandler(new TreeSortDropHandler(tree2(), tree1()));
}
public class TreeSortDropHandler implements DropHandler {
private final Tree tree2;
private final Tree tree1;
/**
* Tree must use {#link HierarchicalContainer}.
*
* #param tree
*/
public TreeSortDropHandler(final Tree tree2,
final Tree tree1) {
this.tree2 = tree2;
this.tree1 = tree1;
}
#Override
public AcceptCriterion getAcceptCriterion() {
// TODO Auto-generated method stub
return AcceptAll.get();
}
#Override
public void drop(DragAndDropEvent dropEvent) {
// TODO Auto-generated method stub
final Transferable t = dropEvent.getTransferable();
// see the comment in getAcceptCriterion()
if (t.getSourceComponent() != tree1
|| !(t instanceof DataBoundTransferable)) {
return;
}
final TreeTargetDetails dropData = ((TreeTargetDetails) dropEvent
.getTargetDetails());
final Object sourceItemId = ((DataBoundTransferable) t).getItemId();
// FIXME: Why "over", should be "targetItemId" or just
// "getItemId"
final Object targetItemId = dropData.getItemIdOver();
// Location describes on which part of the node the drop took
// place
final VerticalDropLocation location = dropData.getDropLocation();
moveNode(sourceItemId, targetItemId, location);
}
private void moveNode(final Object sourceItemId,
Object targetItemId, final VerticalDropLocation location) {
final HierarchicalContainer container = (HierarchicalContainer) tree1
.getContainerDataSource();
if (location == VerticalDropLocation.MIDDLE) {
if (tree1.hasChildren(sourceItemId))
{
Collection<?> children=tree1.getChildren(sourceItemId);
tree2.addItem(tree1.getItemCaption(sourceItemId));
tree2.setParent(tree1.getItemCaption(sourceItemId),targetItemId);
targetItemId=tree2.getItem(tree1.getItemCaption(sourceItemId));
tree2.addItems(children);
tree2.setParent(children,tree2.getItemCaption(sourceItemId));
System.out.print(tree2.getItem(tree1.getItemCaption(sourceItemId)));
System.out.print("//added");
}else {
tree2.addItem(tree1.getItemCaption(sourceItemId));
tree2.setParent(tree1.getItemCaption(sourceItemId),targetItemId);
System.out.print("added");
}
Related
I am trying to develop custom source for parallel GCS content scanning. The naive approach would be to loop through listObjects function calls:
while (...) {
Objects objects = gcsUtil.listObjects(bucket, prefix, pageToken);
pageToken = objects.getNextPageToken();
...
}
The problem is performance for the tens of millions objects.
Instead of the single thread code we can add delimiter / and submit parallel processed for each prefix found:
...
Objects objects = gcsUtil.listObjects(bucket, prefix, pageToken, "/");
for (String subPrefix : object.getPrefixes()) {
scanAsync(bucket, subPrefix);
}
...
Next idea was to try to wrap this logic in Splittable DoFn.
Choice of RestrictionTracker: I don't see how can be used any of exiting RestrictionTracker. So decided to write own. Restriction itself is basically list of prefixes to scan. tryClaim checks if there is more prefixes left and receive newly scanned to append them to current restriction. trySplit splits list of prefixes.
The problem that I faced that trySplit can be called before all subPrefixes are found. In this case current restriction may receive more work to do after it was splitted. And it seems that trySplit is being called until it returns a not null value for a given RestrictionTracker: after certain number of elements goes to the output or after 1 second via scheduler or when ProcessContext.resume() returned. This doesn't work in my case as new prefixes can be found at any time. And I can't checkpoint via return ProcessContext.resume() because if split was already done, possible work that left in current restriction will cause checkDone() function to fail.
Another problem that I suspect that I couldn't achieve parallel execution in DirectRunner. As trySplit was always called with fractionOfRemainder=0 and new RestrictionTracker was started only after current one completed its piece of work.
It would be also great to read more detailed explanation about Splittable DoFn components lifecycle. How parallel execution per element is achieved. And how and when state of RestrictionTracker can be modified.
UPD: Adding simplified code that should show intended implementation
#DoFn.BoundedPerElement
private static class ScannerDoFn extends DoFn<String, String> {
private transient GcsUtil gcsUtil;
#GetInitialRestriction
public ScannerRestriction getInitialRestriction(#Element String bucket) {
return ScannerRestriction.init(bucket);
}
#ProcessElement
public ProcessContinuation processElement(
ProcessContext c,
#Element String bucket,
RestrictionTracker<ScannerRestriction, ScannerPosition> tracker,
OutputReceiver<String> outputReceiver) {
if (gcsUtil == null) {
gcsUtil = c.getPipelineOptions().as(GcsOptions.class).getGcsUtil();
}
ScannerRestriction currentRestriction = tracker.currentRestriction();
ScannerPosition position = new ScannerPosition();
while (true) {
if (tracker.tryClaim(position)) {
if (position.completedCurrent) {
// position.clear();
// ideally I would to get checkpoint here before starting new work
return ProcessContinuation.resume();
}
try {
Objects objects = gcsUtil.listObjects(
currentRestriction.bucket,
position.currentPrefix,
position.currentPageToken,
"/");
if (objects.getItems() != null) {
for (StorageObject o : objects.getItems()) {
outputReceiver.output(o.getName());
}
}
if (objects.getPrefixes() != null) {
position.newPrefixes.addAll(objects.getPrefixes());
}
position.currentPageToken = objects.getNextPageToken();
if (position.currentPageToken == null) {
position.completedCurrent = true;
}
} catch (Throwable throwable) {
logger.error("Error during scan", throwable);
}
} else {
return ProcessContinuation.stop();
}
}
}
#NewTracker
public RestrictionTracker<ScannerRestriction, ScannerPosition> restrictionTracker(#Restriction ScannerRestriction restriction) {
return new ScannerRestrictionTracker(restriction);
}
#GetRestrictionCoder
public Coder<ScannerRestriction> getRestrictionCoder() {
return ScannerRestriction.getCoder();
}
}
public static class ScannerPosition {
private String currentPrefix;
private String currentPageToken;
private final List<String> newPrefixes;
private boolean completedCurrent;
public ScannerPosition() {
this.currentPrefix = null;
this.currentPageToken = null;
this.newPrefixes = Lists.newArrayList();
this.completedCurrent = false;
}
public void clear() {
this.currentPageToken = null;
this.currentPrefix = null;
this.completedCurrent = false;
}
}
private static class ScannerRestriction {
private final String bucket;
private final LinkedList<String> prefixes;
private ScannerRestriction(String bucket) {
this.bucket = bucket;
this.prefixes = Lists.newLinkedList();
}
public static ScannerRestriction init(String bucket) {
ScannerRestriction res = new ScannerRestriction(bucket);
res.prefixes.add("");
return res;
}
public ScannerRestriction empty() {
return new ScannerRestriction(bucket);
}
public boolean isEmpty() {
return prefixes.isEmpty();
}
public static Coder<ScannerRestriction> getCoder() {
return ScannerRestrictionCoder.INSTANCE;
}
private static class ScannerRestrictionCoder extends AtomicCoder<ScannerRestriction> {
private static final ScannerRestrictionCoder INSTANCE = new ScannerRestrictionCoder();
private final static Coder<List<String>> listCoder = ListCoder.of(StringUtf8Coder.of());
#Override
public void encode(ScannerRestriction value, OutputStream outStream) throws IOException {
NullableCoder.of(StringUtf8Coder.of()).encode(value.bucket, outStream);
listCoder.encode(value.prefixes, outStream);
}
#Override
public ScannerRestriction decode(InputStream inStream) throws IOException {
String bucket = NullableCoder.of(StringUtf8Coder.of()).decode(inStream);
List<String> prefixes = listCoder.decode(inStream);
ScannerRestriction res = new ScannerRestriction(bucket);
res.prefixes.addAll(prefixes);
return res;
}
}
}
private static class ScannerRestrictionTracker extends RestrictionTracker<ScannerRestriction, ScannerPosition> {
private ScannerRestriction restriction;
private ScannerPosition lastPosition = null;
ScannerRestrictionTracker(ScannerRestriction restriction) {
this.restriction = restriction;
}
#Override
public boolean tryClaim(ScannerPosition position) {
restriction.prefixes.addAll(position.newPrefixes);
position.newPrefixes.clear();
if (position.completedCurrent) {
// completed work for current prefix
assert lastPosition != null && lastPosition.currentPrefix.equals(position.currentPrefix);
lastPosition = null;
return true; // return true but we would need to claim again if we need to get next prefix
} else if (lastPosition != null && lastPosition.currentPrefix.equals(position.currentPrefix)) {
// proceed work for current prefix
lastPosition = position;
return true;
}
// looking for next prefix
assert position.currentPrefix == null;
assert lastPosition == null;
if (restriction.isEmpty()) {
// no work to do
return false;
}
position.currentPrefix = restriction.prefixes.poll();
lastPosition = position;
return true;
}
#Override
public ScannerRestriction currentRestriction() {
return restriction;
}
#Override
public SplitResult<ScannerRestriction> trySplit(double fractionOfRemainder) {
if (lastPosition == null && restriction.isEmpty()) {
// no work at all
return null;
}
if (lastPosition != null && restriction.isEmpty()) {
// work at the moment only at currently scanned prefix
return SplitResult.of(restriction, restriction.empty());
}
int size = restriction.prefixes.size();
int newSize = new Double(Math.round(fractionOfRemainder * size)).intValue();
if (newSize == 0) {
ScannerRestriction residual = restriction;
restriction = restriction.empty();
return SplitResult.of(restriction, residual);
}
ScannerRestriction residual = restriction.empty();
for (int i=newSize; i<=size; i++) {
residual.prefixes.add(restriction.prefixes.removeLast());
}
return SplitResult.of(restriction, residual);
}
#Override
public void checkDone() throws IllegalStateException {
if (lastPosition != null) {
throw new IllegalStateException("Called checkDone on not completed job");
}
}
#Override
public IsBounded isBounded() {
return IsBounded.UNBOUNDED;
}
}
I'm trying to list all the available phone numbers with display name from contacts app in a ListView with search. Also if a contact has more than one phone number, it has to be displayed in separate list item (as different contact not as same contact in Contacts App).
I've successfully retrived all the phone numbers with display name and displayed in ListView. Multiple phone numbers of a contact also displayed as separate contact.
But, when I search - either it gives irrelevant phone number for the display name or it fails to filter when I entered single character. Please suggest on this.
Here is my code:
public class ContactsListFragment extends ListFragment implements
AdapterView.OnItemClickListener, LoaderManager.LoaderCallbacks<Cursor> {
// Defines a tag for identifying log entries
private static final String TAG = "ContactsListFragment";
private ContactsAdapter mAdapter; // The main query adapter
private String mSearchTerm; // Stores the current search query term
// Contact selected listener that allows the activity holding this fragment to be notified of
// a contact being selected
private OnContactsInteractionListener mOnContactSelectedListener;
/**
* Fragments require an empty constructor.
*/
public ContactsListFragment() {}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
// Let this fragment contribute menu items
setHasOptionsMenu(true);
// Create the main contacts adapter
mAdapter = new ContactsAdapter(getActivity());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
// Inflate the list fragment layout
return inflater.inflate(R.layout.contact_list_fragment, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
// Set up ListView, assign adapter and set some listeners. The adapter was previously
// created in onCreate().
setListAdapter(mAdapter);
getListView().setOnItemClickListener(this);
getListView().setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
}
#Override
public void onAttach(Activity activity){
super.onAttach(activity);
try{
// Assign callback listener which the holding activity must implement. This is used
// so that when a contact item is interacted with (selected by the user) the holding
// activity will be notified and can take further action such as extracting the contact
//details and pass it to AddNewUserDialogFragment
mOnContactSelectedListener = (OnContactsInteractionListener) activity;
}catch(ClassCastException e){
throw new ClassCastException(activity.toString()
+ " must implement OnContactsInteractionListener");
}
}
#Override
public void onPause(){
super.onPause();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// Gets the Cursor object currently bound to the ListView
final Cursor cursor = mAdapter.getCursor();
// Moves to the Cursor row corresponding to the ListView item that was clicked
cursor.moveToPosition(position);
final String displayName = cursor.getString(ContactMobileNumbQuery.DISPLAY_NAME);
final String mobileNumb = cursor.getString(ContactMobileNumbQuery.NUMBER);
mOnContactSelectedListener.onContactSelected(displayName, mobileNumb);
}
/**
* Called when ListView selection is cleared, for example
* when search mode is finished and the currently selected
* contact should no longer be selected.
*/
private void onSelectionCleared() {
// Uses callback to notify activity this contains this fragment
mOnContactSelectedListener.onSelectionCleared();
// Clears currently checked item
getListView().clearChoices();
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater){
// Inflate the menu items
inflater.inflate(R.menu.contact_list_menu, menu);
// Locate the search item
MenuItem searchItem = menu.findItem(R.id.menu_search);
//sets up and configures the ActionBar SearchView
final SearchManager mSearchManager = (SearchManager)getActivity().getSystemService(Context.SEARCH_SERVICE);
// Retrieves the SearchView from the search menu item
final SearchView mSearchView = (SearchView) searchItem.getActionView();
// Assign searchable info to SearchView
mSearchView.setSearchableInfo(mSearchManager.getSearchableInfo(getActivity().getComponentName()));
// Set listeners for SearchView
mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
// Called when the action bar search text has changed. Updates
// the search filter, and restarts the loader to do a new query
// using the new search string.
String newFilter = !TextUtils.isEmpty(newText) ? newText : null;
// Don't do anything if the filter is empty
if(mSearchTerm == null && newText == null){
return true;
}
// Don't do anything if the new filter is the same as the current filter
if(mSearchTerm != null && mSearchTerm.equals(newText)){
return true;
}
// Updates current filter to new filter
mSearchTerm = newFilter;
// Restarts the loader. This triggers onCreateLoader(), which builds the
// necessary content Uri from mSearchTerm.
getLoaderManager().restartLoader(ContactMobileNumbQuery.QUERY_ID, null, ContactsListFragment.this);
return true;
}
});
searchItem.setOnActionExpandListener(new MenuItem.OnActionExpandListener() {
#Override
public boolean onMenuItemActionExpand(MenuItem item) {
// Nothing to do when the action item is expanded
return true;
}
#Override
public boolean onMenuItemActionCollapse(MenuItem item) {
// When the user collapses the SearchView the current search string is
// cleared and the loader restarted.
if(!TextUtils.isEmpty(mSearchTerm)){
onSelectionCleared();
}
mSearchTerm = null;
getLoaderManager().restartLoader(ContactMobileNumbQuery.QUERY_ID, null, ContactsListFragment.this);
return true;
}
});
getLoaderManager().restartLoader(ContactMobileNumbQuery.QUERY_ID, null, ContactsListFragment.this);
}
#Override
public void onSaveInstanceState(Bundle outState){
super.onSaveInstanceState(outState);
if(!TextUtils.isEmpty(mSearchTerm)){
// Saves the current search string
outState.putString(SearchManager.QUERY, mSearchTerm);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item){
return super.onOptionsItemSelected(item);
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
Log.i(TAG, "onCreateLoader starts");
//If this is the loader for finding contacts in the Contacts Provider
if(id == ContactMobileNumbQuery.QUERY_ID){
Uri contentUri;
// There are two types of searches, one which displays all contacts and
// one which filters contacts by a search query. If mSearchTerm is set
// then a search query has been entered and the latter should be used.
if(mSearchTerm == null){
// Since there's no search string, use the content URI that searches the entire
// Contacts table
contentUri = ContactMobileNumbQuery.CONTENT_URI;
}else{
// Since there's a search string, use the special content Uri that searches the
// Contacts table. The URI consists of a base Uri and the search string.
contentUri = Uri.withAppendedPath(Phone.CONTENT_FILTER_URI, Uri.encode(mSearchTerm));
}
// Returns a new CursorLoader for querying the Contacts table. No arguments are used
// for the selection clause. The search string is either encoded onto the content URI,
// or no contacts search string is used. The other search criteria are constants. See
// the ContactsQuery interface.
return new CursorLoader(getActivity(),
contentUri,
ContactMobileNumbQuery.PROJECTION,
ContactMobileNumbQuery.SELECTION,
null,
ContactMobileNumbQuery.SORT_ORDER);
}
Log.e(TAG, "onCreateLoader - incorrect ID provided (" + id + ")");
return null;
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
// This swaps the new cursor into the adapter.
if(loader.getId() == ContactMobileNumbQuery.QUERY_ID){
mAdapter.swapCursor(data);
}
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
if(loader.getId() == ContactMobileNumbQuery.QUERY_ID){
// When the loader is being reset, clear the cursor from the adapter. This allows the
// cursor resources to be freed.
mAdapter.swapCursor(null);
}
}
/**
* This is a subclass of CursorAdapter that supports binding Cursor columns to a view layout.
* If those items are part of search results, it will be bind to the view layout.
*/
private class ContactsAdapter extends CursorAdapter implements SectionIndexer {
private LayoutInflater mInflater; // Stores the layout inflater
private TextAppearanceSpan highlightTextSpan; // Stores the highlight text appearance style
/**
* Instantiates a new Contacts Adapter.
* #param context A context that has access to the app's layout.
*/
public ContactsAdapter(Context context) {
super(context, null, 0);
// Stores inflater for use later
mInflater = LayoutInflater.from(context);
}
#Override
public Object[] getSections() {
// TODO Auto-generated method stub
return null;
}
#Override
public int getPositionForSection(int section) {
// TODO Auto-generated method stub
return 0;
}
#Override
public int getSectionForPosition(int position) {
// TODO Auto-generated method stub
return 0;
}
/**
* Binds data from the Cursor to the provided view.
*/
#Override
public void bindView(View view, Context context, Cursor cursor) {
// Gets handles to individual view resources
final ViewHolder holder = (ViewHolder) view.getTag();
final String displayName = cursor.getString(ContactMobileNumbQuery.DISPLAY_NAME);
final String mobileNumb = cursor.getString(ContactMobileNumbQuery.NUMBER);
final int startIndex = indexOfSearchQuery(displayName);
if (startIndex == -1) {
// If the user didn't do a search, or the search string didn't match a display
// name, show the display name without highlighting
holder.text1.setText(displayName);
holder.mobile_text.setText(mobileNumb);
if (TextUtils.isEmpty(mSearchTerm)) {
} else {
}
}else {
// If the search string matched the display name, applies a SpannableString to
// highlight the search string with the displayed display name
// Wraps the display name in the SpannableString
final SpannableString highlightedName = new SpannableString(displayName);
// Sets the span to start at the starting point of the match and end at "length"
// characters beyond the starting point
highlightedName.setSpan(highlightTextSpan, startIndex,
startIndex + mSearchTerm.length(), 0);
// Binds the SpannableString to the display name View object
holder.text1.setText(highlightedName);
}
}
private int indexOfSearchQuery(String displayName) {
if (!TextUtils.isEmpty(mSearchTerm)) {
return displayName.toLowerCase(Locale.getDefault()).indexOf(
mSearchTerm.toLowerCase(Locale.getDefault()));
}
return -1;
}
/**
* Overrides newView() to inflate the list item views.
*/
#Override
public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
// Inflates the list item layout.
final View itemLayout = mInflater.inflate(R.layout.contacts_list_view_item, viewGroup,false);
// Creates a new ViewHolder in which to store handles to each view resource. This
// allows bindView() to retrieve stored references instead of calling findViewById for
// each instance of the layout.
final ViewHolder holder = new ViewHolder();
holder.text1 = (TextView) itemLayout.findViewById(android.R.id.text1);
holder.text2 = (TextView) itemLayout.findViewById(android.R.id.text2);
holder.mobile_text = (TextView) itemLayout.findViewById(R.id.mobile_text);
// Stores the resourceHolder instance in itemLayout. This makes resourceHolder
// available to bindView and other methods that receive a handle to the item view.
itemLayout.setTag(holder);
// Returns the item layout view
return itemLayout;
}
}
/**
* A class that defines fields for each resource ID in the list item layout. This allows
* ContactsAdapter.newView() to store the IDs once, when it inflates the layout, instead of
* calling findViewById in each iteration of bindView.
*/
private class ViewHolder {
TextView text1;
TextView text2;
TextView mobile_text;
}
/**
* This interface must be implemented by any activity that loads this fragment. When an
* interaction occurs, such as touching an item from the ListView, these callbacks will
* be invoked to communicate the event back to the activity.
*/
public interface OnContactsInteractionListener {
/**
* Called when a contact is selected from the ListView.
* #param contactUri The contact Uri.
*/
public void onContactSelected(String name, String mobile);
/**
* Called when the ListView selection is cleared like when
* a contact search is taking place or is finishing.
*/
public void onSelectionCleared();
// Uses callback to notify activity this contains this fragment
}
/**
* This interface defines constants used by mobile number retrieval queries.
*/
public interface ContactMobileNumbQuery{
final static int QUERY_ID = 1;
//A Content Uri for Phone table
final static Uri CONTENT_URI = Phone.CONTENT_URI;
//The search or filter query Uri
final static Uri FILTER_URI = Phone.CONTENT_FILTER_URI;
final static String SELECTION = Phone.HAS_PHONE_NUMBER + "=1" + " AND " + Phone.DISPLAY_NAME_PRIMARY + "<>''";
final static String SORT_ORDER = Phone.SORT_KEY_PRIMARY;
final static String[] PROJECTION = {
Phone._ID,
Phone.DISPLAY_NAME_PRIMARY,
Phone.LOOKUP_KEY,
Phone.HAS_PHONE_NUMBER,
Phone.NUMBER,
Phone.TYPE,
SORT_ORDER
};
final static int ID = 0;
final static int DISPLAY_NAME = 1;
final static int LOOKUP_KEY = 2;
final static int HAS_PHONE = 3;
final static int NUMBER = 4;
final static int TYPE = 5;
}
}
Can somebody help me to fix it? Thanks in advance!
The below code fixes my issue.
#Override
public void bindView(View view, Context context, Cursor cursor) {
// Gets handles to individual view resources
final ViewHolder holder = (ViewHolder) view.getTag();
final String displayName = cursor.getString(ContactMobileNumbQuery.DISPLAY_NAME);
final String mobileNumb = cursor.getString(ContactMobileNumbQuery.NUMBER);
holder.text1.setText(displayName);
holder.mobile_text.setText(mobileNumb);
}
I want to unmarshal an XML file to java object using JAXB. The XML file is very large and contains some nodes which I want to skip in some cases to improve performance as these elements are non editable by client java program.
A sample XML is as follows:
<Example id="10" date="1970-01-01" version="1.0">
<Properties>...</Properties>
<Summary>...</Summary>
<RawData>
<Document id="1">...</Document>
<Document id="2">...</Document>
<Document id="3">...</Document>
------
------
</RawData>
<Location></Location>
<Title></Title>
----- // more elements
</Example>
I have two use cases:
unmarshal into Example object which contains Properties, Summaries, RawData etc. without skipping any RawData. (already done this part)
unmarshal into Example object which exclude RawData. Elements nested in RawData is very large so do not want to read this in this use case.
Now I want to unmarshal the XML such that RawData can be skipped. I have tried the technique provided at this link.
Using technique provided in above link also skips all elements which come after RawData.
I have fixed the issue with XMLEventReader with following code:
public class PartialXmlEventReader implements XMLEventReader {
private final XMLEventReader reader;
private final QName qName;
private boolean skip = false;
public PartialXmlEventReader(final XMLEventReader reader, final QName element) {
this.reader = reader;
this.qName = element;
}
#Override
public String getElementText() throws XMLStreamException {
return reader.getElementText();
}
#Override
public Object getProperty(final String name) throws IllegalArgumentException {
return reader.getProperty(name);
}
#Override
public boolean hasNext() {
return reader.hasNext();
}
#Override
public XMLEvent nextEvent() throws XMLStreamException {
while (isEof(reader.peek())) {
reader.nextEvent();
}
return reader.nextEvent();
}
#Override
public XMLEvent nextTag() throws XMLStreamException {
return reader.nextTag();
}
#Override
public XMLEvent peek() throws XMLStreamException {
return reader.peek();
}
#Override
public Object next() {
return reader.next();
}
#Override
public void remove() {
reader.remove();
}
#Override
public void close() throws XMLStreamException {
reader.close();
}
private boolean isEof(final XMLEvent e) {
boolean returnValue = skip;
switch (e.getEventType()) {
case XMLStreamConstants.START_ELEMENT:
final StartElement se = (StartElement) e;
if (se.getName().equals(qName)) {
skip = true;
returnValue = true;
}
break;
case XMLStreamConstants.END_ELEMENT:
final EndElement ee = (EndElement) e;
if (ee.getName().equals(qName)) {
skip = false;
}
break;
}
return returnValue;
}
}
While Unmarshalling just pass this eventReader to the unmarshal method
final JAXBContext context = JAXBContext.newInstance(classes);
final Unmarshaller um = context.createUnmarshaller();
Reader reader = null;
try {
reader = new BufferedReader(new FileReader(xmlFile));
final QName qName = new QName("RawData");
final XMLInputFactory xif = XMLInputFactory.newInstance();
final XMLEventReader xmlEventReader = xif.createXMLEventReader(reader);
final Example example =
(Example) um.unmarshal(new PartialXmlEventReader(xmlEventReader, qName));
}
} finally {
IOUtils.closeQuietly(reader);
}
I hope this would help
try {
// First create a new XMLInputFactory
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
// Setup a new eventReader
InputStream in = new FileInputStream("myXml");
XMLEventReader eventReader = inputFactory.createXMLEventReader(in);
// Read the XML document
Example example = null;
while (eventReader.hasNext()) {
XMLEvent event = eventReader.nextEvent();
if (event.isStartElement()) {
StartElement startElement = event.asStartElement();
// If we have a example element we create a new example
if (startElement.getName().getLocalPart().equals("Example")) {
example = new Example();
// We read the attributes from this tag and add the date
// and id attribute to our object
Iterator<Attribute> attributes = startElement
.getAttributes();
while (attributes.hasNext()) {
Attribute attribute = attributes.next();
if (attribute.getName().toString().equals("date")) {
example.setDate(attribute.getValue());
} else if (attribute.getName().toString().equals("id")) {
example.setId(attribute.getValue());
}
}
}
//get the Properties tag and add to object example
if (event.isStartElement()) {
if (event.asStartElement().getName().getLocalPart()
.equals("Properties")) {
event = eventReader.nextEvent();
example.setProperites(event.asCharacters().getData());
continue;
}
}
//get the Summary tag and add to object example
if (event.asStartElement().getName().getLocalPart()
.equals("Summary")) {
event = eventReader.nextEvent();
example.setSummary(event.asCharacters().getData());
continue;
}
// when you encounter the Rawdata tag just continue
//without adding it to the object created
if (event.asStartElement().getName().getLocalPart()
.equals("Rawdata")) {
event = eventReader.nextEvent();
// don't do anything
continue;
}
//get the location tag and add to object example
if (event.asStartElement().getName().getLocalPart()
.equals("Location")) {
event = eventReader.nextEvent();
example.setLocation(event.asCharacters().getData());
continue;
}
// read and add other elements that can be added
}
// If we reach the end of an example element/tag i.e closing tag
if (event.isEndElement()) {
EndElement endElement = event.asEndElement();
if (endElement.getName().getLocalPart().equals("Example")) {
//do something
}
}
}
} catch (FileNotFoundException | XMLStreamException e) {
}
I have the following issue:
a drop down with a list of elements
each of these elements has a fixed key, which is used by the IChoiceRenderer implementation to look up the localized version of the key (it's a standard, utility renderer implemented in a different package)
the list of localized keys is in a properties file, linked to the panel which instantiates the dropdown.
Is there an elegant/reusable solution to have the dropdown display its elements sorted alphabetically ?
In the end, I think using the render is probably the best approach. To make it reusable and efficient, I isolated this in a Behavior.
Here's the code:
import org.apache.wicket.Component;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.markup.html.form.AbstractChoice;
import org.apache.wicket.markup.html.form.IChoiceRenderer;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import static java.util.Arrays.sort;
/**
* This {#link Behavior} can only be used on {#link AbstractChoice} subclasses. It will sort the choices
* according to their "natural display order" (i.e. the natural order of the display values of the choices).
* This assumes that the display value implements {#link Comparable}. If this is not the case, you should
* provide a comparator for the display value. An instance of this class <em>cannot be shared</em> between components.
* Because the rendering can be costly, the sort-computation is done only once, by default,
* unless you set to <code>false</code> the <code>sortOnlyOnce</code> argument in the constructor.
*
* #author donckels (created on 2012-06-07)
*/
#SuppressWarnings({"unchecked"})
public class OrderedChoiceBehavior extends Behavior {
// ----- instance fields -----
private Comparator displayValueComparator;
private boolean sortOnlyOnce = true;
private boolean sorted;
// ----- constructors -----
public OrderedChoiceBehavior() {
}
public OrderedChoiceBehavior(boolean sortOnlyOnce) {
this.sortOnlyOnce = sortOnlyOnce;
}
public OrderedChoiceBehavior(boolean sortOnlyOnce, Comparator displayValueComparator) {
this.sortOnlyOnce = sortOnlyOnce;
this.displayValueComparator = displayValueComparator;
}
// ----- public methods -----
#Override
public void beforeRender(Component component) {
if (this.sorted && this.sortOnlyOnce) { return;}
AbstractChoice owner = (AbstractChoice) component;
IChoiceRenderer choiceRenderer = owner.getChoiceRenderer();
List choices = owner.getChoices();
// Temporary data structure: store the actual rendered value with its initial index
Object[][] displayValuesWithIndex = new Object[choices.size()][2];
for (int i = 0, valuesSize = choices.size(); i < valuesSize; i++) {
Object value = choices.get(i);
displayValuesWithIndex[i][0] = choiceRenderer.getDisplayValue(value);
displayValuesWithIndex[i][1] = i;
}
sort(displayValuesWithIndex, new DisplayValueWithIndexComparator());
List valuesCopy = new ArrayList(choices);
for (int i = 0, length = displayValuesWithIndex.length; i < length; i++) {
Object[] displayValueWithIndex = displayValuesWithIndex[i];
int originalIndex = (Integer) displayValueWithIndex[1];
choices.set(i, valuesCopy.get(originalIndex));
}
this.sorted = true;
}
public Comparator getDisplayValueComparator() {
return this.displayValueComparator;
}
// ----- inner classes -----
private class DisplayValueWithIndexComparator implements Comparator<Object[]> {
// ----- Comparator -----
public int compare(Object[] left, Object[] right) {
Object leftDisplayValue = left[0];
Object rightDisplayValue = right[0];
if (null == leftDisplayValue) { return -1;}
if (null == rightDisplayValue) { return 1;}
if (null == getDisplayValueComparator()) {
return ((Comparable) leftDisplayValue).compareTo(rightDisplayValue);
} else {
return getDisplayValueComparator().compare(leftDisplayValue, rightDisplayValue);
}
}
}
}
Use this extension of DropDownChoice using Java's Collator (basically locale sensitive sorting - take national characters and national sorting rules into account)
Code tested with Wicket 6 and Java 5+:
import java.text.Collator;
import java.util.Comparator;
import java.util.List;
import java.util.Locale;
import org.apache.wicket.Session;
import org.apache.wicket.markup.html.form.DropDownChoice;
import org.apache.wicket.markup.html.form.IChoiceRenderer;
import org.apache.wicket.model.IModel;
import com.google.common.collect.Ordering;
/**
* DropDownChoice which sort its choices (or in HTML's terminology select's options) according it's localized value
* and using current locale based Collator so it's sorted how it should be in particular language (ie. including national characters,
* using right order).
*
* #author Michal Bernhard michal#bernhard.cz 2013
*
* #param <T>
*/
public class OrderedDropDownChoice<T> extends DropDownChoice<T> {
public OrderedDropDownChoice(String id, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer) {
super(id, choices, renderer);
}
public OrderedDropDownChoice(String id, IModel<? extends List<? extends T>> choices) {
super(id, choices);
}
public OrderedDropDownChoice(String id) {
super(id);
}
public OrderedDropDownChoice(
String id,
IModel<T> model,
IModel<? extends List<? extends T>> choices,
IChoiceRenderer<? super T> renderer) {
super(id, model, choices, renderer);
}
#Override
public List<? extends T> getChoices() {
List<? extends T> unsortedChoices = super.getChoices();
List<? extends T> sortedChoices = Ordering.from(displayValueAlphabeticComparator()).sortedCopy(unsortedChoices);
return sortedChoices;
}
private Collator localeBasedTertiaryCollator() {
Locale currentLocale = Session.get().getLocale();
Collator collator = Collator.getInstance(currentLocale);
collator.setStrength(Collator.TERTIARY);
return collator;
}
private Comparator<T> displayValueAlphabeticComparator() {
final IChoiceRenderer<? super T> renderer = getChoiceRenderer();
return new Comparator<T>() {
#Override
public int compare(T o1, T o2) {
Object o1DisplayValue = renderer.getDisplayValue(o1);
Object o2DisplayValue = renderer.getDisplayValue(o2);
return localeBasedTertiaryCollator().compare(o1DisplayValue, o2DisplayValue);
}
};
}
}
Copied from https://gist.github.com/michalbcz/7236242
If you want a Wicket-based solution you can try to sort the list with something like that:
public class ChoiceRendererComparator<T> implements Comparator<T> {
private final IChoiceRenderer<T> renderer;
public ChoiceRendererComparator(IChoiceRenderer<T> renderer) {
this.renderer = renderer;
}
#SuppressWarnings("unchecked")
public int compare(T o1, T o2) {
return ((Comparable<Object>) renderer.getDisplayValue(o1)).compareTo(renderer.getDisplayValue(o2));
}
}
Usage:
List<Entity> list = ...
IChoiceRenderer<Entity> renderer = ...
Collections.sort(list, new ChoiceRendererComparator<Entity>(renderer));
DropDownChoice<Entity> dropdown = new DropDownChoice<Entity>("dropdown", list, renderer);
The solution we use at my company is Javascript based, we set a special css class on the dropdowns we want to be sorted, and a little jQuery trick does the sort.
Facing the same problem, I moved part of the localisation data from my XMLs to the database, implemented a matching Resolver and was able to use the localized Strings for sorting.
The table design and hibernate configuration was kind of tricky and is described here: Hibernate #ElementCollection - Better solution needed.
The ResourceLoader is along these lines:
public class DataBaseStringResourceLoader extends ComponentStringResourceLoader {
private static final transient Logger logger = Logger
.getLogger(DataBaseStringResourceLoader.class);
#Inject
private ISomeDAO someDao;
#Inject
private IOtherDao otherDao;
#Inject
private IThisDAO thisDao;
#Inject
private IThatDAO thatDao;
#Override
public String loadStringResource(Class<?> clazz, String key, Locale locale,
String style, String variation) {
String resource = loadFromDB(key, new Locale(locale.getLanguage()));
if (resource == null) {
resource = super.loadStringResource(clazz, key, locale, style, variation);
}
return resource;
}
private String loadFromDB(String key, Locale locale) {
String resource = null;
if (locale.getLanguage() != Locale.GERMAN.getLanguage()
&& locale.getLanguage() != Locale.ENGLISH.getLanguage()) {
locale = Locale.ENGLISH;
}
if (key.startsWith("some") || key.startsWith("other")
|| key.startsWith("this") || key.startsWith("that")) {
Integer id = Integer.valueOf(key.substring(key.indexOf(".") + 1));
ILocalizedObject master;
if (key.startsWith("some")) {
master = someDao.findById(id);
} else if (key.startsWith("other")) {
master = otherDao.findById(id);
} else if (key.startsWith("this") ){
master = thisDao.findById(id);
} else {
master = thatDao.findById(id);
}
if (master != null && master.getNames().get(locale) != null) {
resource = master.getNames().get(locale).getName();
} else if (master == null) {
logger.debug("For key " + key + " there is no master.");
}
}
return resource;
}
[...]
}
I am facing an issue in storing data in persistence store,i am trying to store events for different dates in persistence store but the data is getting overridden the code is :
public ListEventScreen(Vector v,String timezone) {
for(int i=0;i<v.size();i++){
EventBean bean=(EventBean)v.elementAt(i);
//a normal label in the app, just to display text, anchored left
LabelField label = new LabelField(bean.getSummary(),LabelField.FIELD_LEFT);
//add the label to the screen
add(label);
saveUserInfo(v);
}
}
public void saveUserInfo(Vector vectorData){
// static{
store = PersistentStore.getPersistentObject( 0x1dfc10ec9447eb14L );
synchronized(store) {
store.setContents(vectorData);
store.commit();
}
//}
}
Please let me know what has to be changed.
Every time you call store.setContents(), the current contents of the persistentStore are overwritten with the Vector you are passing in. You need to make sure you are loading the previous events that were already in the persistentStore into your Vector before then adding new events into that Vector that you are then saving.
You are also calling saveUserInfo() on every iteration of your loop in ListEventScreen(). You should be calling it outside of the loop instead.
I would do something like this:
public ListEventScreen(Vector v,String timezone) {
Enumeration e = v.elements();;
while (e.hasMoreElements()){
EventBean bean = (EventBean) e.nextElement();
//a normal label in the app, just to display text, anchored left
LabelField label = new LabelField(bean.getSummary(),LabelField.FIELD_LEFT);
//add the label to the screen
add(label);
}
}
public void loadUserInfo(Vector vectorData){
// static{
store = PersistentStore.getPersistentObject( 0x1dfc10ec9447eb14L );
synchronized(store) {
Vector v = (Vector) store.getContents();
Enumeration e = v.elements();
while (e.hasMoreElemens){
vectorData.add(e.nextElement());
}
}
//}
}
public void saveUserInfo(Vector vectorData){
// static{
store = PersistentStore.getPersistentObject( 0x1dfc10ec9447eb14L );
synchronized(store) {
store.setContents(vectorData);
store.commit();
}
//}
}
.
{
Vector v = new Vector();
loadUserInfo(v);
ListEventScreen(v, ...);
... modify v contents as needed ...
saveUserInfo(v);
}
If you do not mind changing the format of your persistent store contents, I would wrap the store in a singleton class instead:
public class EventBeans extends Vector implements Persistable
{
private static final long persistKey = 0x1dfc10ec9447eb14L;
private static EventBeans _instance = null;
private static PersistentObject _persist = null;
static{
_persist = PersistentStore.getPersistentObject(persistKey);
_instance = (EventBeans) _persist.getContents();
if (_instance == null){
_instance = new EventBeans();
_persist.setContents(_instance);
_persist.commit();
}
}
private EventBeans(){
super();
}
public static EventBeans getInstance(){
return _instance;
}
public static synchronized void save(){
_persist.commit();
}
}
.
{
Vector v = EventBeans.getInstance();
ListEventScreen(v, ...);
... modify v contents as needed ...
EventBeans.save();
}