I have two class like this :
public class Forecast {
private List<Element> elements;
private Person person;
}
public class Element {
private String element;
}
I have a constant of String[] like this :
private static final String[] ELE = {"element1", "element2", "element3"};
I would like to retrieve all the elements of my list in forecast which contains one of the elements of my constant with Stream.
So, I started by doing this to test :
public List<Element> getElement(String person) {
return getElement(person).getList()
.stream()
.filter(r -> r.get(0).getElement.equals("element1"))
.collect(Collectors.toList());
}
Now I would like to use my constant ELE, and I don't find how to go through it and test my elements
Thanks
private static final List<String> ELE_LIST = java.util.Arrays.asList(ELE);
public List<Element> getElement(String person) {
return getElement(person).getList()
.stream()
.filter(r -> ELE_LIST.contains(r.get(0).getElement()))
.collect(Collectors.toList());
}
Related
For example in the Select component the selected value is rendered as shown here. However when it comes to the ComboBox it is not rendered, only on the dropdown as shown here. I need to use the ComboBox because I need the search functionality, that is to have the item selected as they type in the value because there may be a lot of values. Ideally it would be great to merge the Select and ComboBox but barring that I'm wondering if there's a way to render the selected value.
You can't use an arbitrary Renderer, because the text input is, well, a text input. As noted in the comments below the question, what you're really after is an icon in front of the value of the input, and while there's no nice API in ComboBox for this, you can frankenstein together a solution using the prefix slot of the vaadin-text-field input. I've adapted an example using the Cookbook recipe here. Note that there's an enhancement request that would make handling prefix/suffix components in ComboBox easier: https://github.com/vaadin/flow-components/issues/1594
public class AboutView extends Div {
public AboutView() {
ComboBox<Person> comboBox = new ComboBox<>();
comboBox.setItems(getPersons());
// Renderer for the drop down
comboBox.setRenderer(new ComponentRenderer<Div, Person>(person -> {
Div container = new Div();
container.add(person.getIcon().create(), new Span(person.getName()));
return container;
}));
// on value change: either clear the prefix slot or create a new Icon there
comboBox.addValueChangeListener(e -> {
Person p = e.getValue();
if (p == null) {
PrefixUtil.clearSlot(comboBox, "prefix");
return;
}
PrefixUtil.setPrefixComponent(comboBox, p.getIcon().create());
});
comboBox.setItemLabelGenerator(Person::getName);
add(comboBox);
}
public List<Person> getPersons() {
List<Person> persons = new ArrayList<>();
Person person1 = new Person("Foo", VaadinIcon.ARROW_BACKWARD);
Person person2 = new Person("Bar", VaadinIcon.BAR_CHART);
Person person3 = new Person("Baz", VaadinIcon.PUZZLE_PIECE);
persons.add(person1);
persons.add(person2);
persons.add(person3);
return persons;
}
public static class Person {
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
private String name;
public VaadinIcon getIcon() {
return icon;
}
public void setIcon(VaadinIcon icon) {
this.icon = icon;
}
private VaadinIcon icon;
public Person(String name, VaadinIcon icon) {
this.name = name;
this.icon = icon;
}
}
public static class PrefixUtil {
private static Stream<Element> getElementsInSlot(HasElement target,
String slot) {
return target.getElement().getChildren()
.filter(child -> slot.equals(child.getAttribute("slot")));
}
public static void setPrefixComponent(Component target, Component component) {
clearSlot(target, "prefix");
if (component != null) {
component.getElement().setAttribute("slot", "prefix");
target.getElement().appendChild(component.getElement());
}
}
private static void clearSlot(Component target, String slot) {
getElementsInSlot(target, slot).collect(Collectors.toList())
.forEach(target.getElement()::removeChild);
}
private static Component getChildInSlot(HasElement target, String slot) {
Optional<Element> element = getElementsInSlot(target, slot).findFirst();
if (element.isPresent()) {
return element.get().getComponent().get();
}
return null;
}
public static Component getPrefixComponent(Component target) {
return getChildInSlot(target, "prefix");
}
}
}
I have json like following
{"data": [
{
"instance": { ...
"inner"" {....
.............}
}
}]
"isvalid":true
"nextVal" : <some num>
}
and POJO like
class A{
private String data;
private boolean isvalid;
private String nextVal;
//with getter setters and proper jackson annotations
}
These can have variable structure inside data, so with object mapper.read I want to take entire data object in string!
have tried direct serialization to my simple object which obviously gives error and also tried JSONNode
mapper.readValue(jsonString, JsonNode.class);
String content = node.get("data").textValue();
This returns blank
anyway I can achieve that to take entire data object value in string with objectmapper?
I tried toString and returned just fine what I wanted - entire data object as String
JsonNode node = (ObjectNode) mapper.readValue(jsonString, JsonNode.class);
node.get("data").toString();
The reason it returns blank is because, data is an array. You need to deseralise it in to JsonArray. Assuming your JSON structure as below,
{
"data": [
{"instance": {
"inner": {
"id": "1"
}
}
}],
"isvalid": true,
"nextVal": 1
}
This will be deserialised using below code (in JSONNode),
List<JsonNode> list = node.findValues("data");
for(JsonNode n: list){
JsonNode in1 = n.findValue("instance");
JsonNode in2 = in1.findValue("inner");
String abc = in2.findValue("id").textValue();
System.out.println(abc);
}
You need to have the POJO structure as shown above. The data will be list of instance object. instance object will have to have inner object.
Update:
Outer node = mapper.readValue(jsonstr, Outer.class);
The classes which needs to be created would be as shown below.
public class Outer {
private List<Data> data;
Boolean valid;
Integer nextval;
public List<Data> getData() {
return data;
}
public void setData(List<Data> data) {
this.data = data;
}
public Boolean isValid() {
return valid;
}
public void setValid(Boolean valid) {
this.valid = valid;
}
public Integer getNextval() {
return nextval;
}
public void setNextval(Integer nextval) {
this.nextval = nextval;
}
}
public class Data {
Instance instance;
public Instance getInstance() {
return instance;
}
public void setInstance(Instance instance) {
this.instance = instance;
}
}
public class Instance {
private Inner inner;
public Inner getInner() {
return inner;
}
public void setInner(Inner inner) {
this.inner = inner;
}
}
public class Inner {
private String id;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
}
I'm programming an application Web (Semantic Web) and for storing the triples, using sesame, and for mapping of data alibaba. My question is, that way I have to implement the classes,to that at the base of triplets is store an object as a subclass of another , try interfaces but I got no results , below I present the "entities":
the parent class:
import java.math.BigInteger;
import org.openrdf.annotations.Iri;
#Iri(Parent.NS + "Parent")
public interface Parent {
public static final String NS = "http://www.spelta.ec/ontology/example#";
#Iri(Parent.NS +"code")
BigInteger getCode();
#Iri(Parent.NS +"code")
void setCode(BigInteger code);
#Iri(Parent.NS+"description")
String getDescription();
#Iri(Parent.NS+"description")
void setDescription(String description);
}
The child class:
import java.math.BigInteger;
public class Child implements Parent {
private BigInteger code;
private String description;
#Override
public BigInteger getCode() {
return code;
}
#Override
public void setCode(BigInteger code) {
this.code = code;
}
#Override
public String getDescription() {
return description;
}
#Override
public void setDescription(String description) {
this.description = description;
}
}
to consult the store of triples, should define an instance of the Children class is a subclass of Parent
many thanks
I'm trying to follow the new Cineasts app with SDN 4.0.0.M1 and SpringBoot to learn Spring and Neo4j but I have an error when I try to access the movie url with
curl http://localhost:8080/movies
MappingException: Error mapping GraphModel to instance
I implemented the minimum to get something working so the code is simple but I probably forgot something
the movie class
#NodeEntity
public class Movie {
#GraphId
private Long nodeId;
private String id;
private String title;
public Movie() {
}
public Movie(String id, String title) {
this.id = id;
this.title = title;
}
}
the associated MovieRepository is empty at the moment
public interface MovieRepository extends GraphRepository<Movie> {
}
the MovieController
#Autowired
private MovieRepository movieRepository;
#Autowired
private Session session;
#RequestMapping(value = "/movies/{id}", method = RequestMethod.GET, headers = "Accept=application/json")
public
#ResponseBody
Movie getMovie(#PathVariable String id) {
return IteratorUtil.firstOrNull(findMovieByProperty("id", id));
}
public Iterable<Movie> findMovieByProperty(String propertyName, Object propertyValue) {
return session.loadByProperty(Movie.class, new Property(propertyName, propertyValue));
}
and the main class with database connection
#SpringBootApplication
#EnableNeo4jRepositories("cineasts.repository")
#EnableTransactionManagement
public class CineastsApplication extends Neo4jConfiguration {
public static final int NEO4J_PORT = 7474;
#Bean
public Neo4jServer neo4jServer() {
return new RemoteServer("http://localhost:" + NEO4J_PORT);
}
#Override
public SessionFactory getSessionFactory() {
return new SessionFactory("org.neo4j.cineasts.domain");
}
#Override
#Bean
#Scope(value = "session", proxyMode = ScopedProxyMode.TARGET_CLASS)
public Session getSession() throws Exception {
return super.getSession();
}
public static void main(String[] args) {
SpringApplication.run(CineastsApplication.class, args);
}
}
I started Neo4j and added one record with Neo4j browser
CREATE (m:Movie {id:1, name:'The Matrix'}) return m
when I go to localhost:8080 I can see the json response
{
"_links" : {
"movies" : {
"href" : "http://localhost:8080/movies"
},
"profile" : {
"href" : "http://localhost:8080/alps"
}
}
but it fails to display the movies or http://localhost:8080/movies/1 record I just created. Any idea to fix this or get a more relevant message?
Thanks!
The problem could be the fact that your entity definition does not match that of the node you've created.
The Movie class defines a property id of data type String, and a property title of type String.
The Cypher you used however
CREATE (m:Movie {id:1, name:'The Matrix'}) return m
creates a node with a number id instead of a String id and a name property instead of a title property.
Changing the above to
CREATE (m:Movie {id:'1', title:'The Matrix'}) return m
should fix it.
This question already has answers here:
Conversion Error setting value for 'null Converter' - Why do I need a Converter in JSF?
(2 answers)
Closed 7 years ago.
Is a Converter necessary for a <h:selectOneMenu> or <p:selectOneMenu> with arbitrary user-created classes as its values? I mean, is the following code supposed to work without a converter?
<p:selectOneMenu value="#{bean.language}">
<f:selectItems value="#{bean.allLanguages}" />
</p:selectOneMenu>
and
#Named(value = "bean")
#ConversationScoped
public class Bean {
private Language language; // appropriate getter and setter are present
public List<SelectItem> getAllLanguages() {
// populates a list of select items with Strings as item labels and Languages as item values
}
}
I have a similar code with an enum as the type (Language) and it works perfectly. But when I replace the type with a normal java class, I get a conversion error.
You need a converter here, as JSF will assume strings by default, that is the way you coded it. JSF has no idea how to convert your pseudo entities to strings and vice versa.
Some notes:
1 . Your getAsString method defines your identifier for your entities/POJOs, not what the JSF (or whatever) select gets as itemLabel.
2 . Your converter can dig into the DB for real entities using this infamous article:
http://balusc.blogspot.de/2011/09/communication-in-jsf-20.html#ConvertingAndValidatingGETRequestParameters
You can also use CDI annotations with that "pattern".
3 . Your value = "bean"is redundant and the CDI scope of choice is usually #ViewScoped. However, you have to keep in mind that CDI #Named + JSF #ViewScoped isn't working together without using Seam 3 or Apache MyFaces CODI.
You do not need a converter, if you use this little class that I wrote :-) It can back selectOne and selecteMany components. It requires that your class's toString() provides a one-to-one unique representation of your object. If you like, you could substitute a method name other than toString(), like toIDString()
To use ListBacker in your ManagedBean, use ListBacker<Type> wherever you would have used List<Type>
#ManagedBean
#RequestScoped
public class BackingBean {
private ListBacker<User> users; // +getter +setter
#PostConstruct
public void init() {
// fill it up from your DAO
users = new ListBacker<User>(userDAO.find());
}
// Here's the payoff! When you want to use the selected object,
// it is just available to you, with no extra database hits:
User thisOneIsSelected = users.getSelectedItemAsObject();
// or for multi-select components:
List<User> theseAreSelected = users.getSelectedItemsAsObjects();
}
In your xhtml file:
<p:selectOneMenu value="#{backingBean.users.selectedItem}">
<f:selectItems value="#{backingBean.users.contents}" var="item" itemValue="#{item.value}" itemLabel="#{item.label}" />
</p:selectOneMenu>
The ListBacker class:
public class ListBacker<T extends AbstractEntityBase> {
// Contains the String representation of an Entity's ID (a.k.a.
// primary key) and the associated Entity object
Map<String, T> contents = new LinkedHashMap<String, T>(); // LinkedHashMap defaults to insertion-order iteration.
// These hold values (IDs), not labels (descriptions).
String selectedItem; // for SelectOne list
List<String> selectedItems; // for SelectMany list
public class ListItem {
private String value;
private String label;
public ListItem(String value, String label) {
this.value = value;
this.label = label;
}
public String getValue() {
return value;
}
public String getLabel() {
return label;
}
}
public ListBacker() {}
public ListBacker(List<T> lst) {
put(lst);
}
public void clear() {
contents.clear();
selectedItem = null;
if(selectedItems != null) {
selectedItems.clear();
}
}
public List<ListItem> getContents() {
return convert(contents);
}
public String getSelectedItem() {
return selectedItem;
}
public void setSelectedItem(String selectedItem) {
this.selectedItem = selectedItem;
}
public List<String> getSelectedItems() {
return selectedItems;
}
public void setSelectedItems(List<String> selectedItems) {
this.selectedItems = selectedItems;
}
public T getSelectedItemAsObject() {
return convert(selectedItem);
}
public List<T> getSelectedItemsAsObjects() {
return convert(selectedItems);
}
public void put(T newItem) {
contents.put(newItem.toString(), newItem);
}
public void put(List<T> newItems) {
for (T t : newItems) {
put(t);
}
}
// PROTECTED (UTILITY) METHODS
protected List<ListItem> convert(Map<String, T> maps) {
List<ListItem> lst = new ArrayList<ListItem>();
for (Entry<String, T> e : maps.entrySet()) {
lst.add(new ListItem(e.getKey(), e.getValue().desc()));
}
return lst;
}
protected List<T> convert(List<String> ids) {
List<T> lst = new ArrayList<T>();
for (String id : ids) {
lst.add(convert(id));
}
return lst;
}
protected T convert(String id) {
return contents.get(id);
}
}
I have two toString() implementations, one for JPA entities:
public abstract class AbstractEntityBase {
#Override
public final String toString() {
return String.format("%s[id=%s]", getClass().getSimpleName(), getIdForToString().toString());
}
/**
* Return the entity's ID, whether it is a field or an embedded ID class..
* #return ID Object
*/
protected abstract Object getIdForToString();
}
and one for JPA EmbeddedId's:
public abstract class CompositeKeyBase {
#Override
public final String toString() {
return String.format("%s[id=%s]", getClass().getSimpleName(), getIdForToString());
}
/**
* Supports the class's toString() method, which is required for ListBacker.
* Compile a string of all ID fields, with this format:
* fieldName=StringVALUE,field2=STRINGvAlUE2,...,fieldx=stringvalue <br />
* Recommended: start with Eclipse's "generate toString()" utility and move it to getIdForToString()
* #return a 1-to-1 String representation of the composite key
*/
public abstract String getIdForToString();
}
An example implementation of getIdForToString(), for an entity that has one Id field:
#Override
public Object getIdForToString() {
return userID;
}
An example implementation of getIdForToString(), for an EmbeddedId that has two fields:
#Override
public String getIdForToString() {
return "userID=" + userID + ",roleID=" + roleID;
}