Develop Reference

Is there any way to get the variable as the parameter as the '&' does in c++ in java?

I would like to create a void method that could change the value of the given parameter. I Tried to modify it in the method but it didn't work because it's modifying a copy of the variable.
I Know I can do it in c++ as following :
void Foo::myMethod(MyObject& obj);
I know I can use the return statement in my methods but I would Like to know if there's a way to do as above in java and here is what I tried :
public class LocalCallbackTest {
public static class MyClass {
private MyClass oldClass = null;
private MyClass newClass = null;
private int value = 0;
public MyClass() {
}
public MyClass(MyClass old) {
this();
oldClass = old;
}
/**
* #return the newClass
*/
public MyClass getNewClass() {
return newClass;
}
/**
* #return the oldClass
*/
public MyClass getOldClass() {
return oldClass;
}
/**
* #return the value
*/
public int getValue() {
return value;
}
/**
* #param newClass the newClass to set
*/
public void setNewClass(MyClass newClass) {
this.newClass = newClass;
}
/**
* #param oldClass the oldClass to set
*/
public void setOldClass(MyClass oldClass) {
this.oldClass = oldClass;
}
/**
* #param value the value to set
*/
public void setValue(int value) {
this.value = value;
}
#Override
public String toString() {
StringBuilder sb = new StringBuilder();
if (oldClass != null)
sb.append("old class : \n\t").append(oldClass.getValue()).append("\n");
if (newClass != null)
sb.append("new class : \n\t").append(newClass.getValue()).append("\n");
sb.append("actual class : \n\t").append(value).append("\n");
return sb.toString();
}
private MyClass rollBack() {
if (this.oldClass != null) {
this.oldClass.setNewClass(this);
return oldClass;
}
return this;
}
private MyClass nextMember() {
if (this.newClass != null) {
this.newClass.setOldClass(this);
return newClass;
}
return this;
}
public static boolean rollBack(MyClass param) {
if (param != (param = param.rollBack())) {
return true;
}
return false;
}
public static boolean nextMember(MyClass param) {
if (param != (param = param.nextMember())) {
return true;
}
return false;
}
public static void test(int i) {
i++;
}
}
public static void main(String[] args) {
MyClass test = new MyClass();
test.setValue(0);
for (int i = 1; i <= 5; i++) {
MyClass test2 = new MyClass();
test2.setValue(i);
test2.setOldClass(test);
test.setNewClass(test2);
test = test.getNewClass();
System.out.println(test.getValue());
}
int val=2;
MyClass.test(val);
System.out.println(val);
}
}
thank you for your Help.

In C++ you can pass parameters either by copy or by reference (with the &), but in Java, you can only pass an object as a reference, so any object you pass as a parameter will be modified exactly how you want it without having to return it. (like with an & in C++) if it does not work in your example, it's probably because of some logic.

Infinite recursion Nested Objects

I have found few similar threads about infinity loop while trying save object as Json, but most of them are about java + jpa, and these solutions don't work for me. I would like to create tree structure of some data. There is class ProjectNode which got
private ArrayList<ProjectNode> children;
field. I'm pretty sure this one course the problem but its the main field in this structure, I can't ignore it. I have tested and I can convert object which has list with node which doesn't have children, but cant if any child got another children in the below code:
public class ProjectNode implements Comparable<ProjectNode>{
private String parent;
private String nodeName;
private String nodeHref;
private boolean hasChild;
private int td;
private ArrayList<ProjectNode> children;
public ProjectNode() {
super();
// TODO Auto-generated constructor stub
}
+ getters and setters
ObjectMapper objectMapper = new ObjectMapper();
String json = objectMapper.writeValueAsString(parser.getProjectFactory().get(12));
parser.getProjectFactory() returns list of ParentNodes (parent=null), I would like to convert 12 elements because there is a case where node has child and this child has child. Cause this error:
Exception in thread "main" com.fasterxml.jackson.databind.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"]->java.util.ArrayList[31]->ProjectNode["children"])
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:734)
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:119)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:79)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:18)
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727)
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719)
EDIT:
Parser - parse project/hosts list from cacti:
public List<ProjectNode> getProjectFactory() throws FailingHttpStatusCodeException, MalformedURLException, IOException {
FileWriter fstream = new FileWriter("graphMap.txt");
BufferedWriter out = new BufferedWriter(fstream);
String [] hostInfo = null;
HtmlTableCell cel= (HtmlTableCell) page.getHtmlPage().getByXPath("/html/body/table/tbody/tr[5]/td[1]").get(0);
System.out.println(cel.getChildElementCount());
List<HtmlDivision> divs = cel.getByXPath(".//div");
System.out.println(divs.size());
//checks if list of host has been added to the project
ProjectTree projectTree = new ProjectTree();
Map<Integer,String> suppMap = new HashMap<Integer,String>();
for(HtmlDivision div : divs) {
List<DomNode> td = div.getByXPath(".//table/tbody/tr/td");
if(td.size()>2) {
ProjectNode pn = new ProjectNode(getNameSrc(td).split("#")[0],getNameSrc(td).split("#")[1],td.size());
hostInfo = getNameSrc(td).split("#");
if(pn.getTd()>3) {
if(!suppMap.get(pn.getTd()-1).isEmpty()) {
pn.setParent(suppMap.get(pn.getTd()-1));
}
if(suppMap.get(pn.getTd())!=null){
suppMap.remove(pn.getTd());
}
suppMap.put(pn.getTd(), pn.getNodeName());
projectTree.addNodeToTree(pn);
} else {
projectTree.addNodeToTree(pn);
suppMap.put(pn.getTd(), pn.getNodeName());
//out.write(pn.toString()+"\n");
}
}
}
ArrayList<ProjectNode> pns = projectTree.getNodeList();
Collections.sort(pns, Comparator.comparing(ProjectNode::getTd));
Collections.reverse(pns);
projectTree.setNodeList(pns);
List<ProjectNode> finalList = new ArrayList<ProjectNode>();
for(ProjectNode pn :pns ) {
if(pn.getTd()==3) {
finalList.add(pn);
}else {
projectTree.addToParent(pn);
}
}
Collections.reverse(finalList);
for(ProjectNode pn : finalList) {
Collections.sort(pn.getChildren());
}
out.write(finalList.get(12).getChildren().get(4).getChildren().toString());
out.close();
System.out.println(finalList.size());
return finalList;
}
ProjectTree class
public class ProjectTree {
private ProjectNode rootNode;
private ArrayList<ProjectNode> NodeList;
public ProjectTree() {
super();
this.NodeList = new ArrayList<ProjectNode>();
}
public ProjectTree(ProjectNode rootNode, ArrayList<ProjectNode> nodeList) {
super();
this.rootNode = rootNode;
NodeList = nodeList;
}
public ArrayList<ProjectNode> groupHosts(){
return this.NodeList;
}
public void addToParent(ProjectNode pn) {
for(ProjectNode pnA :this.NodeList) {
if(pnA.getNodeName().equals(pn.getParent())) {
if(pnA.getChildren()!=null && pnA.getChildren().size()!=0) {
pnA.sortChildren();
}
pnA.addChlild(pn);
}
}
}
public ProjectNode getRootNode() {
return rootNode;
}
public void setRootNode(ProjectNode rootNode) {
this.rootNode = rootNode;
}
public ArrayList<ProjectNode> getNodeList() {
return NodeList;
}
public void setNodeList(ArrayList<ProjectNode> nodeList) {
NodeList = nodeList;
}
}
ProjectNode.class
public class ProjectNode implements Comparable<ProjectNode>{
private String parent;
private String nodeName;
private String nodeHref;
private boolean hasChild;
private int td;
private ArrayList<ProjectNode> children;
public ProjectNode() {
super();
// TODO Auto-generated constructor stub
}
public ProjectNode( String nodeName, String nodeHref, int td) {
super();
this.nodeName = nodeName;
this.nodeHref = nodeHref;
this.hasChild =false;
this.td=td;
}
public void addChlild(ProjectNode pn) {
if(children!=null) {
this.children.add(pn);
}else {
this.children = new ArrayList<ProjectNode>();
this.children.add(pn);
}
}
public List<ProjectNode> getChildren() {
return children;
}
public void sortChildren() {
Collections.sort(this.getChildren());;
//Collections.sort(this.getChildren(), Comparator.comparing(ProjectNode::getNodeName));
//System.out.println(this.children.toString());
}
public void setChildren(ArrayList<ProjectNode> children) {
this.children = children;
}
public int getTd() {
return td;
}
public void setTd(int td) {
this.td = td;
}
public boolean isHasChild() {
return hasChild;
}
public void setHasChild(boolean hasChild) {
this.hasChild = hasChild;
}
public String getParent() {
return parent;
}
public void setParent(String parent) {
this.parent = parent;
}
public String getNodeName() {
return nodeName;
}
public void setNodeName(String nodeName) {
this.nodeName = nodeName;
}
public String getNodeHref() {
return nodeHref;
}
public void setNodeHref(String nodeHref) {
this.nodeHref = nodeHref;
}
#Override
public String toString() {
return "ProjectNode [parent=" + parent + ", nodeName=" + nodeName + ", nodeHref=" + nodeHref + ", hasChild="
+ hasChild + ", td=" + td + ", children=" +"]";
}
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((children == null) ? 0 : children.hashCode());
result = prime * result + (hasChild ? 1231 : 1237);
result = prime * result + ((nodeHref == null) ? 0 : nodeHref.hashCode());
result = prime * result + ((nodeName == null) ? 0 : nodeName.hashCode());
result = prime * result + ((parent == null) ? 0 : parent.hashCode());
result = prime * result + td;
return result;
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
ProjectNode other = (ProjectNode) obj;
if (children == null) {
if (other.children != null)
return false;
} else if (!children.equals(other.children))
return false;
if (hasChild != other.hasChild)
return false;
if (nodeHref == null) {
if (other.nodeHref != null)
return false;
} else if (!nodeHref.equals(other.nodeHref))
return false;
if (nodeName == null) {
if (other.nodeName != null)
return false;
} else if (!nodeName.equals(other.nodeName))
return false;
if (parent == null) {
if (other.parent != null)
return false;
} else if (!parent.equals(other.parent))
return false;
if (td != other.td)
return false;
return true;
}
#Override
public int compareTo(ProjectNode o) {
// TODO Auto-generated method stub
return nodeName.compareTo(o.getNodeName());
}
}
I would use recursive to groupd all nodes in corect place but i had same error (with stackoverflow) so i had to use work around which is addToParent() function.

I have managed it by breaking loop when parent of my node have been found. I made it just for performance because before even if parent has been found loop was checking all elements anyway so i added break, and it works.. Not sure why..
Code below:
public void group() {
int td = this.highestTd;
while (td > 2) {
List<ProjectNode> toRemove = new ArrayList<ProjectNode>();
for (ProjectNode pnA : this.NodeList) {
if(pnA.getTd()==3) {
pnA.setParent("root");
}
if (pnA.getTd() == td) {
for (ProjectNode pnB : this.NodeList) {
System.out.println(pnB.toString());
if (pnA.getParent()!=null && pnA.getParent().equals(pnB.getNodeName())) {
System.out.println("Dodaje "+pnA.getNodeName() + " Do "+pnB.getNodeName());
pnB.addChlild(pnA);
toRemove.add(pnA);
break;
}
}
}
}
td--;
this.NodeList.removeAll(toRemove);
}
}

instantiate the recursively defined composite generic classes in java

I defined classes Graph containing GraphNode as follows, my intention for declaring N is to compare 2 GraphNode objects using generics.
The question is how shall I instantiate the Graph which is recursively bound.
error while declaring as below.
Graph<Integer,Comparable<GraphNode>> graph = new Graph<>();
Bound mismatch: The type Comparable<GraphNode> is not a valid substitute for the bounded parameter <N extends Comparable<GraphNode<T,N>>> of the type Graph<T,N>
public class Graph<T, N extends Comparable<GraphNode<T, N>>> {
private N root;
private Class<N> clazz;
Graph(Class<N> clazz) {
this.clazz = clazz;
}
public N getInstance() {
try {
return clazz.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
return null;
} catch (IllegalAccessException e) {
e.printStackTrace();
return null;
}
}
#SuppressWarnings("unchecked")
public void insert(T d, N n) {
if (root == null && n == null)
root = getInstance();
if (root == null)
root = n;
N node = root;
while (node != null) {
if (node.equals(n)) {
N newNode = getInstance();
((GraphNode<T, N>) newNode).setAdjNode(newNode);
}
}
}
}
public class GraphNode<T, N extends Comparable<GraphNode<T, N>>> implements Comparable<N> {
private T data;
private LinkedHashSet<N> adjNodes = new LinkedHashSet<>();
GraphNode() {
data = null;
}
GraphNode(T d) {
setData(d);
}
public void setAdjNode(N n) {
adjNodes.add(n);
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
#Override
public int hashCode() {
return data.hashCode();
}
#Override
public boolean equals(Object obj) {
if (obj instanceof GraphNode<?, ?>) {
return ((GraphNode<?, ?>) obj).getData() == this.getData();
}
return false;
}
#Override
public String toString() {
return data + "";
}
#Override
public int compareTo(N o) {
return this.compareTo(o);
}
}

This solved my above problem
public class Graph<T extends Comparable<T>> {
private GraphNode<T> root;
public void insert(T d, GraphNode<T> n) {
if (root == null && n == null)
root = new GraphNode<T>(d);
if (root == null)
root = n;
GraphNode<T> node = root;
Queue<GraphNode<T>> queue = new ConcurrentLinkedQueue<>();
queue.add(root);
while (!queue.isEmpty()) {
node = queue.poll();
node.setNodeColor(color.BLACK);
if (node.equals(n)) {
GraphNode<T> newNode = new GraphNode<T>(d);
((GraphNode<T>) newNode).setAdjNode(newNode);
} else {
queue.addAll(node.getUnexploredAdjNodes());
}
}
}
}
public class GraphNode<T extends Comparable<T>> implements Comparable<GraphNode<T>> {
enum color {
WHITE, GREY, BLACK
};
private T data;
private color nodeColor = color.WHITE;
private LinkedHashSet<GraphNode<T>> adjNodes = new LinkedHashSet<>();
GraphNode() {
data = null;
}
GraphNode(T d) {
setData(d);
}
public void setAdjNode(GraphNode<T> n) {
adjNodes.add(n);
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
public LinkedHashSet<GraphNode<T>> getAdjNodes() {
return adjNodes;
}
public LinkedHashSet<GraphNode<T>> getUnexploredAdjNodes() {
LinkedHashSet<GraphNode<T>> n = new LinkedHashSet<>();
for (GraphNode<T> node : adjNodes) {
if (node.getNodeColor() == color.WHITE)
n.add(node);
}
return n;
}
public color getNodeColor() {
return nodeColor;
}
public void setNodeColor(color nodeColor) {
this.nodeColor = nodeColor;
}
#Override
public int hashCode() {
return data.hashCode();
}
#Override
public boolean equals(Object obj) {
if (obj instanceof GraphNode<?>) {
return ((GraphNode<?>) obj).getData() == this.getData();
}
return false;
}
#Override
public int compareTo(GraphNode<T> o) {
return data.compareTo(o.data);
}
#Override
public String toString() {
return data + "";
}
}
Graph<Integer> graph = new Graph<>();

Make Custom Control Generic

I have created a Custom JavaFX Control, Call it ComboBoxTablePopup, it's a Generic Control witch takes a list of items of type S from the user.
Internally, i have used some sort of filtering in the TableView(a child of ComboboxTablePopup Contrl).So i have used :
FiltredList.setPridcate(S -> {
if (pr == null || pr.isEmpty() || pr.length() == 0)
return true;
if (((Engine) S).getDesignation().toLowerCase().contains(pr.toLowerCase())) {
return true;
} else
return false;).
Because i'm using generic class and the list can be of any type i have to cast filtredlist items to well known object in ordre to get filtring work.
So, how can i make the predicate function generic, so i can work with any object and filtre it ?
Here is the code of my CustomControl:
public class ComboBoxTablePopup<S> extends ComboBoxBase {
private
ObservableList<TableColumn> columns = FXCollections.emptyObservableList();
public ObservableList<TableColumn> getColumns() {
return columns;
}
public void setColumns(ObservableList<TableColumn> columns) {
this.columns = columns;
}
/***************************************************************************
* *
* Static properties and methods *
* *
**************************************************************************/
private static <T> StringConverter<T> defaultStringConverter() {
return new StringConverter<T>() {
#Override
public String toString(T t) {
return t == null ? null : t.toString();
}
#Override
public T fromString(String string) {
return (T) string;
}
};
}
/***************************************************************************
* *
* Constructors *
* *
**************************************************************************/
/**
* Creates a default ComboboxTablePopup instance with an empty
* {#link #itemsProperty() items} list and default
* {#link #selectionModelProperty() selection model}.
*/
public ComboBoxTablePopup() {
this(FXCollections.<S>emptyObservableList());
}
/**
* Creates a default ComboboxTablePopup instance with the provided items list and
* a default {#link #selectionModelProperty() selection model}.
*/
public ComboBoxTablePopup(ObservableList<S> items) {
setItems(items);
getStyleClass().add(DEFAULT_STYLE_CLASS);
setEditable(true);
setPromptText("Plz Search for a pirticular term");
}
public ComboBoxTablePopup(ObservableList<S> items, ObservableList<TableColumn> columns) {
this(items);
this.columns = columns;
}
private static final String DEFAULT_STYLE_CLASS = "combobox-table-popup";
private ReadOnlyObjectWrapper<TextField> editor;
private ObjectProperty<ObservableList<S>> items = new SimpleObjectProperty<ObservableList<S>>(this, "items");
public final void setItems(ObservableList<S> value) {
itemsProperty().set(value);
}
public final ObservableList<S> getItems() {
return items.get();
}
public ObjectProperty<ObservableList<S>> itemsProperty() {
return items;
}
// Converter
public ObjectProperty<StringConverter<S>> converterProperty() {
return converter;
}
private ObjectProperty<StringConverter<S>> converter =
new SimpleObjectProperty<StringConverter<S>>(this, "converter", ComboBoxTablePopup.<S>defaultStringConverter());
public final void setConverter(StringConverter<S> value) {
converterProperty().set(value);
}
public final StringConverter<S> getConverter() {
return converterProperty().get();
}// Create a symmetric (format/parse) converter with the default locale.
// Editor
public TextField getEditor() {
return editorProperty().get();
}
public ReadOnlyObjectProperty<TextField> editorProperty() {
if (editor == null) {
editor = new ReadOnlyObjectWrapper<TextField>(this, "editor");
editor.set(new ComboBoxListViewSkin.FakeFocusTextField());
}
return editor.getReadOnlyProperty();
}
#Override
protected Skin<?> createDefaultSkin() {
return new ComboBoxTablePopupSkin<>(this);
}
}
public class ComboBoxTablePopupSkin<S> extends ComboBoxPopupControl {
private ComboBoxTablePopup comboBoxTablePopup;
private ObservableList<S> comboboxTablePopupItems;
private TextField displayNode;
private TableView<S> tableViewPopupContent;
FilteredList<S> filtredList;
private SortedList<S> sortedList;
private Predicate<S> predicate;
private final InvalidationListener itemsObserver;
private final ListChangeListener<S> tableViewItemsListener = new ListChangeListener<S>() {
#Override
public void onChanged(ListChangeListener.Change<? extends S> c) {
getSkinnable().requestLayout();
}
};
private final WeakListChangeListener<S> weakListViewItemsListener =
new WeakListChangeListener<S>(tableViewItemsListener);
public ComboBoxTablePopupSkin(ComboBoxTablePopup comboBoxTablePopup) {
super(comboBoxTablePopup, new ComboBoxTablePopupBehavior(comboBoxTablePopup));
this.comboBoxTablePopup = comboBoxTablePopup;
setupTablePredicate();
updateComboBoxTablePopupItems();
itemsObserver = observable -> {
updateComboBoxTablePopupItems();
updateTableViewItems();
};
this.comboBoxTablePopup.itemsProperty().addListener(new WeakInvalidationListener(itemsObserver));
tableViewPopupContent = createTableView();
tableViewPopupContent.setManaged(false);
getChildren().add(tableViewPopupContent);
updateTableViewItems();
getEditor().textProperty().addListener((obv, oldValue, newValue) -> {
if (!newValue.isEmpty())
comboBoxTablePopup.show();
filtreData(newValue);
});
registerChangeListener(comboBoxTablePopup.itemsProperty(), "ITEMS");
registerChangeListener(comboBoxTablePopup.valueProperty(), "VALUE");
registerChangeListener(comboBoxTablePopup.editorProperty(), "EDITABLE");
}
private void setupTablePredicate() {
}
private void updateTableViewItems() {
filtredList = new FilteredList<S>(comboboxTablePopupItems, p -> true);
sortedList = new SortedList<S>(filtredList);
sortedList.comparatorProperty().bind(tableViewPopupContent.comparatorProperty());
tableViewPopupContent.setItems(sortedList);
}
private void filtreData(String pr) {
String data = pr;
filtredList.setPredicate(engine -> {
if (pr == null || pr.isEmpty() || pr.length() == 0)
return true;
if (((Engine) engine).getDesignation().toLowerCase().contains(pr.toLowerCase())) {
return true;
} else
return false;
});
}
public void updateComboBoxTablePopupItems() {
comboboxTablePopupItems = comboBoxTablePopup.getItems();
comboboxTablePopupItems = comboboxTablePopupItems == null ? FXCollections.<S>emptyObservableList() : comboboxTablePopupItems;
}
private TableView<S> createTableView() {
final TableView<S> tableView = new TableView<>();
tableView.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
tableView.setFocusTraversable(false);
tableView.getSelectionModel().selectedItemProperty().addListener(o -> {
int index = tableView.getSelectionModel().getSelectedIndex();
System.out.println("selected item changed");
});
for (TableColumn tblColumn : tableColumns()) {
tableView.getColumns().add(tblColumn);
}
tableView.setOnKeyPressed(e -> {
if (e.getCode() == KeyCode.ENTER ||
e.getCode() == KeyCode.ESCAPE ||
e.getCode() == KeyCode.SPACE) {
S selectedItem = tableView.getSelectionModel().getSelectedItem();
if (selectedItem != null) {
System.out.println(((Engine) selectedItem).getDesignation());
getEditor().setText(((Engine) selectedItem).getDesignation());
comboBoxTablePopup.setValue(selectedItem);
comboBoxTablePopup.hide();
}
}
});
return tableView;
}
private ObservableList<TableColumn> tableColumns() {
return ((ComboBoxTablePopup) getSkinnable()).getColumns();
}
#Override
protected Node getPopupContent() {
return this.tableViewPopupContent;
}
#Override
protected TextField getEditor() {
return ((ComboBoxTablePopup) getSkinnable()).getEditor();
}
#Override
protected StringConverter getConverter() {
return ((ComboBoxTablePopup) getSkinnable()).getConverter();
}
#Override
public Node getDisplayNode() {
if (displayNode == null) {
displayNode = getEditableInputNode();
displayNode.getStylesheets().add("ComboBoxTable-display-node");
updateDisplayNode();
}
displayNode.setEditable(comboBoxTablePopup.isEditable());
return displayNode;
}
#Override
protected void handleControlPropertyChanged(String p) {
super.handleControlPropertyChanged(p);
if ("TEXT".equals(p)) {
if (!getEditor().textProperty().get().isEmpty()) {
comboBoxTablePopup.show();
}
filtreData(getEditor().textProperty().get());
} else if ("ITEMS".equals(p)) {
updateComboBoxTablePopupItems();
} else if ("EDITABLE".equals(p)) {
getEditableInputNode();
}
}
}

Use the StringConverter to convert the item to a String or use a similar property.
public class ComboBoxTablePopupSkin<S> extends ComboBoxPopupControl<S> {
...
private static final StringConverter DEFAULT_CONVERTER = new StringConverter() {
#Override
public String toString(Object o) {
return o == null ? null : o.toString();
}
#Override
public Object fromString(String s) {
throw new UnsupportedOperationException();
}
};
public final StringConverter<S> getConverter() {
StringConverter<S> converter = converterProperty().get();
// fix in case the property is set to a null
return converter == null ? DEFAULT_CONVERTER : converter;
}
private void filtreData(String pr) {
if (pr == null || pr.isEmpty()) {
filtredList.setPredicate(null);
} else {
final StringConverter<S> converter = ((ComboBoxTablePopup<S>) getSkinnable()).getConverter();
final String data = pr.toLowerCase();
filtredList.setPredicate(object -> {
String s = converter.toString(object);
return s != null && s.toLowerCase().contains(data);
});
}
}

jsp checkbox value not binding

I have a problem in getting checkbox's value from JSP.
I used SpringMVC, and my related class as follows:
Form:
#Getter #Setter
public class Sample3Form extends AbstractForm {<
private List<Sample1Bean> sampleList; //all data
private ValidPagedListHolder<Sample1Bean> samplePagedList;//1 page data
}
the class to control changing page:
ValidPagedListHolder:
#SuppressWarnings("serial")
public class ValidPagedListHolder<E> extends PagedListHolder<E> implements
Serializable {
...
...
/**
* Return a sub-list representing the current page.
*/
#Override
#Valid
public List<E> getPageList() {
return super.getPageList();
}
/**
* コンストラクタ生成時の初期化処理を行うメソッド
*/
protected void init() {
setPageSize(DEFAULT_PAGE_SIZE);
}
}
Sample1Bean:
#Getter #Setter
public class Sample1Bean extends AbstractOnlineDataBean {
private String keiyakuno;
private String keiyakunm;
private String torisakino;
}
Parent Bean Class:
#Getter
#Setter
public abstract class AbstractOnlineDataBean extends AbstractDataBean {
private Integer selectedIndex;
private String maskPattern;
}
Controller:
#Controller
#RequestMapping(value = "app/sample3")
#SessionAttributes(value = "sample3Form")
#NotCheckToken
public class SampleController3 extends AbstractController {
private static Logger logger = LoggerFactory.getLogger(UserUtil.class);
#ModelAttribute(value = "sample3Form")
public Sample3Form getForm() {
return new Sample3Form();
}
......
......
#RequestMapping(value = "delete")
public String delete(Model model, #Validated Sample3Form form, BindingResult result, HttpServletRequest request) throws GdcSystemException {
List<Sample1Bean> list = new ArrayList<Sample1Bean>();
int size = form.getSampleList().size();
ValidPagedListHolder<Sample1Bean> plist = form.getSamplePagedList();
list = plist.getPageList();
for (int i = 0 ; i < size; i ++) {
if (form.getSampleList().get(i).getSelectedIndex() == null ) {
} else {
//I cannot arrive here even though I checked in JSP
list.add(form.getSampleList().get(i));
}
}
...
...
}
JSP:
<ab:form id="sample3" action="submit" modelAttribute="sample3Form">
<table width="100%" class="tableborder" cellpadding="0" cellspacing="0">
...
...
<ab:tr index="${row.index}">
<td width="2%" class="data_list_area">
<ab:checkbox path="${sample3Form.samplePagedList.pageList[row.index].selectedIndex}" fwformat='NONE'
value="${sample3Form.samplePagedList.page * sample3Form.samplePagedList.pageSize + row.index }" name="checkedids"/>
</td>
<td width="5%" class="data_list_area">
<!--ab:out value="${sample3Form.samplePagedList.pageList[row.index].keiyakuno}" /-->
<ab:label path="" fwformat='NONE'>${sample3Form.samplePagedList.pageList[row.index].keiyakuno}</ab:label>
</td>
...
...
In above JSP, I set checkboxes and bind the checkboxes to selectedIndex property for for every row data.but i cannot get selected row in controller as follows:
form.getSampleList().get(i).getSelectedIndex()
The return value is always null.
why? Could who please tell me how i can get the selectedIndex in controller?
By the way, I can get checked row in controller like below:
String[] arr = request.getParameterValues("checkedids");
Remarks: in JSP, These added checkboxes is defined by name "checkedids".
and <ab:checkbox> is a tag class extends AbstractSingleCheckedElementTag.
the src for CheckboxTagImpl is here:
public class CheckboxTagImpl extends AbstractSingleCheckedElementTag {
private String maskPatterns = null;
private boolean escapeMaskFlg = false;
/**
*
* #return
*/
public String getMaskPatterns() {
return maskPatterns;
}
/**
*
* #param maskPatterns
*/
public void setMaskPatterns(String maskPatterns) {
this.maskPatterns = maskPatterns;
}
/**
* #return
*/
public Boolean isEscapeMaskFlg() {
return escapeMaskFlg;
}
/**
* #param escapeMaskFlg
*/
public void setEscapeMaskFlg (Boolean escapeMaskFlg) {
this.escapeMaskFlg = escapeMaskFlg;
}
#Override
protected int writeTagContent(TagWriter tagWriter) throws JspException {
if (maskPatterns != null) {
FormTagImpl formTag = TagUtil.getFormTag(this);
String formClassName = formTag.getModelAttribute();
String maskPattern = TagUtil.getMaskPattern(formClassName, pageContext);
if (maskPattern != null) {
String[] maskPatternArray = maskPatterns.split(",");
for (int i = 0; i < maskPatternArray.length; i++) {
if (maskPattern.equals(maskPatternArray[i])) {
setDisabled(true);
break;
}
}
}
}
FormTagImpl formTag = TagUtil.getFormTag(this);
String formClassName = formTag.getModelAttribute();
Boolean maskFlg = TagUtil.getMaskFlg(formClassName, pageContext);
if (maskFlg == true && escapeMaskFlg == false) {
setDisabled(true);
}
if (!isDisabled()) {
// Write out the 'field was present' marker.
tagWriter.startTag("input");
tagWriter.writeAttribute("type", "hidden");
String name = WebDataBinder.DEFAULT_FIELD_MARKER_PREFIX + getName();
tagWriter.writeAttribute("id", getId());
tagWriter.writeAttribute("name", name);
tagWriter.writeAttribute("value", processFieldValue(name, SystemConstant.FLAG_OFF, getInputType()));
tagWriter.endTag();
}
super.writeTagContent(tagWriter);
return SKIP_BODY;
}
#Override
protected void writeTagDetails(TagWriter tagWriter) throws JspException {
tagWriter.writeAttribute("type", getInputType());
Object boundValue = getBoundValue();
Class<?> valueType = getBindStatus().getValueType();
if (Boolean.class.equals(valueType) || boolean.class.equals(valueType)) {
// the concrete type may not be a Boolean - can be String
if (boundValue instanceof String) {
boundValue = Boolean.valueOf((String) boundValue);
}
Boolean booleanValue = (boundValue != null ? (Boolean) boundValue : Boolean.FALSE);
renderFromBoolean(booleanValue, tagWriter);
} else if (String.class.equals(valueType) && getValue() == null) {
renderFromValue(SystemConstant.FLAG_ON, tagWriter);
}
else {
Object value = getValue();
if (value == null) {
throw new IllegalArgumentException("Attribute 'value' is required when binding to non-boolean values");
}
Object resolvedValue = (value instanceof String ? evaluate("value", value) : value);
renderFromValue(resolvedValue, tagWriter);
}
}
#Override
public void doFinally() {
if (PropertiesUtil.getProperty("cleanAtDoFinally").equals("true")) {
super.doFinally();
this.maskPatterns = null;
this.escapeMaskFlg = false;
setDisabled(false);
}
}
#Override
protected String getInputType() {
return "checkbox";
}
#Override
protected String getName() throws JspException {
if (getPath()==null) {
return super.getName();
} else {
return getPath();
}
}
#Override
protected BindStatus getBindStatus() throws JspException {
BindStatus bindStatus = null;
if (bindStatus == null) {
// HTML escaping in tags is performed by the ValueFormatter class.
String nestedPath = getNestedPath();
String pathToUse = (nestedPath != null ? nestedPath + getPath() : getPath());
if (pathToUse.endsWith(PropertyAccessor.NESTED_PROPERTY_SEPARATOR)) {
pathToUse = pathToUse.substring(0, pathToUse.length() - 1);
}
bindStatus = new BindStatus(getRequestContext(), pathToUse, false);
}
return bindStatus;
}
}
Thanks.