Calling method with variable arguments from JSF 2.0 - jsf

In a backing bean I declared following method
public boolean hasPermission(Object... objects) {
...
}
And I'm trying to call it from JSF 2.0 as follows:
<c:set var="hasPermission" scope="view" value="#{restrictions.hasPermission(entity)}" />
And it throws
javax.el.ELException: Cannot convert Entity of class com.testing.Entity to class [Ljava.lang.Object;
If I pass two arguments, then it throws
Method hasPermission not found
Can I somehow call varargs methods from JSF 2.0?

Varargs is not officially supported in EL. At least, it's nowhere specified in EL specification. There does also not seem to be any plans to introduce it in the upcoming EL 3.0.
You need to look for a different solution. As the functional requirement is unclear, I can't suggest any one.
Update it seems that the Apache EL parser as supplied in Tomcat supports this. It at least isn't supported by Sun/Oracle EL parser as supplied in Glassfish.

On Tomcat 7 JSF 2.1.4 following works
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Insert title here</title>
</head>
<body>
<h:form>
<h:commandButton value="click 1"
action="#{test.var('a','b',1,test.i,test.d,test.s,test.ss)}"/>
<h:commandButton value="click 2"
action="#{test.var('a','b',1)}"/>
<h:commandButton value="click 3"
action="#{test.var(test.i,test.d,test.s,test.ss)}"/>
</h:form>
</body>
</html>
The Bean:
#ManagedBean
public class Test {
private Integer i = 10;
private Double d = 10.0;
private String s = "varargs";
private String[] ss = new String[]{"1","2","3"};
public Integer getI() {
return i;
}
public void setI(Integer i) {
this.i = i;
}
public Double getD() {
return d;
}
public void setD(Double d) {
this.d = d;
}
public String getS() {
return s;
}
public void setS(String s) {
this.s = s;
}
public String[] getSs() {
return ss;
}
public void setSs(String[] ss) {
this.ss = ss;
}
public void var(Object...objects){
System.out.println(Arrays.toString(objects));
}
}
Output : on click 1,2,3
[a, b, 1, 10, 10.0, varargs, [Ljava.lang.String;#4fa9cba5]
[a, b, 1]
[10, 10.0, varargs, [Ljava.lang.String;#26b923ee]
Is this what you are looking for.... as the way you are trying to call in question is blank.

Related

Why does id remain zero? [duplicate]

This question already has answers here:
Creating master-detail pages for entities, how to link them and which bean scope to choose
(2 answers)
Closed 3 years ago.
I'm working on one school project, where i need to use JSF to make CRUD app.
I'm using MySQL database, and managed to make list of all objects, delete button, and i have trouble with edit button.
When i click on edit it redirect me to edit.xhtml page, get id and fill all fields based on that id.
When i click update button on edit page, it always change customer with id=0.
I have one java doc with getter, setter and methods
have two views index.xhtml and edit.xhtml
and one page with method for connection with database.
All other methods work fine, except update.
Customer.java
#ManagedBean
#RequestScoped
public class Customer {
private int id;
private String username;
private String adress;
private int quantity;
private double price;
private Map<String, Object> sessionMap = FacesContext.getCurrentInstance().getExternalContext().getSessionMap();
public String edit() {
FacesContext fc = FacesContext.getCurrentInstance();
Map<String, String> params = fc.getExternalContext().getRequestParameterMap();
String primarId = params.get("action");
System.out.println(primarId);
try {
DatabaseConnection dbc = new DatabaseConnection();
Connection connection = dbc.getConnection();
Statement st = connection.createStatement();
ResultSet rs = st.executeQuery("select * from customer where customer_id=" + primarId);
Customer customer = new Customer();
rs.next();
customer.setUsername(rs.getString("username"));
customer.setAdress(rs.getString("adress"));
customer.setQuantity(rs.getInt("quantity"));
customer.setPrice(rs.getDouble("price"));
sessionMap.put("editcustomer", customer);
} catch (SQLException ex) {
System.out.println(ex);
}
return "/edit.xhtml?faces-redirect=true";
}
public String updateCustomer() {
FacesContext fc = FacesContext.getCurrentInstance();
Map<String, String> params = fc.getExternalContext().getRequestParameterMap();
String fieldId = params.get("action");
System.out.println(fieldId);
try {
DatabaseConnection dbc = new DatabaseConnection();
Connection connection = dbc.getConnection();
PreparedStatement ps = connection.prepareStatement("update customer set username=?,adress=?,quantity=?,price=? where customer_id=?");
ps.setString(1, username);
ps.setString(2, adress);
ps.setInt(3, quantity);
ps.setDouble(4, price);
ps.setInt(5, id);
System.out.println(id);
ps.executeUpdate();
} catch (SQLException ex) {
System.out.println(ex);
}
return "/index.xhtml?faces-redirect=true";
}
edit.xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<h:head>
<title>Facelet Title</title>
</h:head>
<h:body>
<center>
<h:form>
Username: <h:inputText value="#{editcustomer.username}"></h:inputText> <br/>
Adress: <h:inputText value="#{editcustomer.adress}"></h:inputText> <br/>
Quantity: <h:inputText value="#{editcustomer.quantity}"></h:inputText> <br/>
Price: <h:inputText value="#{editcustomer.price}"></h:inputText> <br/><br/>
<h:commandButton value="Update" action="#{editcustomer.updateCustomer()}">
<f:param name="action" value="#{editcustomer.id}" />
</h:commandButton>
</h:form>
</center>
</h:body>
</html>
when I run this code the ID stays 0
I think the problem is the #RequestScoped annotation in the bean. With this annotation data only "lives" in the current page. As you are redirecting to another URL (altough it is the same one), you lose your changes (more taking into account that you are putting the customer in the session map. Try using #SessionScoped instead.
Hope it works.

Can you set an Ajax response action to a PrimeFace component which's html is generated in a Bean?

Dear friendly strangers,
using PrimeFaces 7.0 on JSF 2.2 I'm generating html-Code in my Bean and inject it in my xhtml with <h:outputText value="#{myBean.myHtml}" escape="false"/>. This naturally doesn't work with <p:.../> components, as they themselves generate/render actual html. The way I alter the data from my Database to get the final html is too complicated for html functions though, so I still wanna do it in my Java-Beans instead of using lots of ui:repeat and hypercomplex custom styles - even though I know this is not how jsf/PrimeFaces is meant to be used. Now checking the actual rendered html e.g. of a p:commandLink it gives
<a id="myContainerID:myComponentID" href="#" class="ui-commandlink ui-widget" onclick="PrimeFaces.ab({s:"myContainerID:myComponentID",f:"myContainerID"});return false;">myComponentValue</a>
,which I can generate easily, but the response-action called when receiving the component's Ajax request (s:"myContainerID:myComponentID") will be missing, which seems to be saved somewhere in the moment the actual html is generated with <p:...>.
Is there a way to manually set that response-action, if so how/where?
EDIT: Since (quoting PrimeFaces.ab function)
//ajax shortcut
ab: function(cfg, ext) {
return PrimeFaces.ajax.AjaxRequest(cfg, ext);
}
The PrimeFaces.ajax.AjaxRequest can be asynchronous or synchronous. The AjaxRequest uses the AjaxUtils, which handles all
send, process, response, and update.
PrimeFaces.ajax.AjaxRequest = function(cfg, ext) {
cfg.ext = ext;
if(cfg.async) {
return PrimeFaces.ajax.AjaxUtils.send(cfg);
}
else {
return PrimeFaces.ajax.Queue.offer(cfg);
} }
I suppose the answer, if there is any, should lay somewhere in AjaxUtils, but couldn't find it yet.
Thanks helluvalot for any suggestion/help.
EDIT 2: I did eventually manage to transcribe it all to the xhtml with nested ui:repeats and lots of custom styles, I'm still curious though whether there's a way to do it with in-Bean-generated html.
ExampleCode
myBean:
#ManagedBean(name = "myBean")
#SessionScoped
public class myBean {
private String html1;
private String html2;
#PostConstruct
public void init() {
html1 = "<p:commandLink id=\"myComponentID\" value=\"myComponentValue\" "
+ "action=\"#{someBean.doSomething()}\"";
html2 = "<a id=\"myContainerID:myComponentID\" "
+ "href=\"#\" class=\"ui-commandlink ui-widget\" "
+ "onclick=\"PrimeFaces.ab({s:\"myContainerID:myComponentID\","
+ "f:\"myContainerID\"});"
+ "return false;\">1. myComponentValue</a>";
}
public String getHtml1() {
return html1;
}
public void setHtml1(String html1) {
this.html1 = html1;
}
public String getHtml2() {
return html2;
}
public void setHtml2(String html2) {
this.html2 = html2;
}
}
myIndex.xhtml:
<h:html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:p="http://primefaces.org/ui"
>
<h:head>
</h:head>
<h:body>
<h:form id="myContainerID">
<h:outputText value="#{myBean.html1}" escape="false" />
<h:outputText value="#{myBean.html2}" escape="false" />
</h:form>
</h:body>
</h:html>

Value of <h:selectBooleanCheckbox> is not updated according to backing bean value

I'm using JSF2 and Tomcat server. I programmed a simple example in which:
User Selects a faculty from "h:selectOneMenu"
Upon selection, the value of "h:inputText" is changed to "odd" or "even" based on facultyNo
Also, upon selection, the value of "h:selectBooleanCheckBox" is changed to "checked" if facultyNo is even and "not checked" if facultyNo is odd
Everything works fine for "h:inputText". On the other hand, the value of "h:selectBooleanCheckBox" does not change. Why is this happening?
By the way, the use of boolean value inside a HashMap is intentional because the project I'm working on has lots of boolean values in a HashMap. So, replacing the Hashmap with a simple boolean property and using a getter and a setter for it is definitely not a solution for my case.
The code for the xhtml page is below:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<head>
<title>Dummy Title</title>
</head>
<body>
<h:form>
<label for="faculty">Faculty</label>
<h:selectOneMenu id="faculty" value="#{test.selectedFaculty}" converter="faccon" valueChangeListener="#{test.facultyChange}" onchange="submit()">
<f:selectItems value="#{start.app.faculties}"/>
</h:selectOneMenu>
<h:selectBooleanCheckbox id="mycheck" value="#{test.x.get(0)}"></h:selectBooleanCheckbox>
<h:outputText value="#{test.res}"></h:outputText>
<h:commandButton value="Save" action="#{test.saveChoices}" />
</h:form>
</body>
</html>
The code for the backing bean is below
import java.io.Serializable;
import java.util.HashMap;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.event.ValueChangeEvent;
import com.myWork.Application;
import com.myWork.Faculty;
#ManagedBean(name="test")
#RequestScoped
public class TestBean implements Serializable
{
private HashMap<Integer,Boolean> x;
private String res;
private Faculty selectedFaculty;
#PostConstruct
public void init(){
Application app = Application.getInstance();
selectedFaculty = app.getFaculties()[0];
x = new HashMap<Integer, Boolean>();
if (selectedFaculty.getFacultyNo()%2==0)
{
x.put(0, true);
res = "even";
}
else
{
x.put(0, false);
res = "odd";
}
}
public HashMap<Integer,Boolean> getX() {
return x;
}
public void setX(HashMap<Integer,Boolean> x) {
this.x = x;
}
public Faculty getSelectedFaculty() {
return selectedFaculty;
}
public void setSelectedFaculty(Faculty selectedFaculty) {
this.selectedFaculty = selectedFaculty;
}
public String getRes() {
return res;
}
public void setRes(String res) {
this.res = res;
}
public void facultyChange(ValueChangeEvent e){
Faculty fac = (Faculty) e.getNewValue();
if (fac.getFacultyNo()%2==0)
{
x.put(0, true);
res = "even";
}
else
{
x.put(0, false);
res = "odd";
}
}
public String saveChoices(){
return "test";
}
}
Any help is greatly appreciated.
Actually your problem is not related to JSF, it is related to EL. in your case, EL treat you map keys as long not int, so you should change your map to be:
HashMap<Long, Boolean> map = new HashMap<>();
and set the key values as follows :
map.put(0L, false);
map.put(1L, true);
to force it to be auto-boxed to long.
Note: the problem described in detailed in the following question :
EL access a map value by Integer key
In order to send updates to a different component, you can make use of partial page rendering by making Ajax calls to send parameters to Managed bean.
Within <h:selectBooleanCheckBox>
<h:selectOneMenu id="faculty" value="#{test.selectedFaculty}" converter="faccon" valueChangeListener="#{test.facultyChange}">
<f:selectItems value="#{start.app.faculties}"/>
</h:selectOneMenu>
<h:selectBooleanCheckbox id="mycheck" valueChangeListener="#{test.facultyChange}" value="#{test.x.get(0)}">
<f:ajax event="change" execute="#form" render="faculty"/>
</h:selectBooleanCheckbox>
Edit: Removed call to onSubmit() in selectOneMenu. introduced an ajax call in selectBooleanCheckbox for partial page refresh.
Refer full solution at this post.

Initialize a composite component based on the provided attributes

I'm writing my custom table composite component with Mojarra JSF. I'm also trying to bind that composite to a backing component. The aim is to be able to specify the number of elements the table has in a composite attribute, later on the bound backing component will autogenerate the elements itself before view gets rendered. I've this sample code:
Main page:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:comp="http://java.sun.com/jsf/composite/comp">
<h:head />
<body>
<h:form>
<comp:myTable itemNumber="2" />
</h:form>
</body>
</html>
myTable.xhtml:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:composite="http://java.sun.com/jsf/composite"
xmlns:h="http://java.sun.com/jsf/html">
<h:body>
<composite:interface componentType="components.myTable">
<composite:attribute name="itemNumber"
type="java.lang.Integer" required="true" />
</composite:interface>
<composite:implementation>
<h:dataTable value="#{cc.values}" var="value">
<h:column headerText="column">
#{value}
<h:commandButton value="Action" action="#{cc.action}" />
</h:column>
</h:dataTable>
</composite:implementation>
</h:body>
</html>
MyTable.java:
#FacesComponent("components.myTable")
public class MyTable extends UINamingContainer {
private List<String> values = new ArrayList<String>();
public void action() {
System.out.println("Called");
}
#Override
public void encodeBegin(FacesContext context) throws IOException {
// Initialize the list according to the element number
Integer num = (Integer) getAttributes().get("itemNumber");
for (int i = 0; i < num; i++) {
values.add("item" + i);
}
super.encodeBegin(context);
}
public List<String> getValues() {
return values;
}
}
The issue is table gets rendered properly (in this case with two items), but action method doesn't get called when pressing the button on the lines.
If I follow the wiki page for composite components, I can get it work in that way, but having to initialize the List each time getValues() is called, introducing logic into the getter method :-(.
Any idea about that? It seems to be a trouble related with overriding encodeBegin method. I also tried initializing it on markInitialState, but attributes are not yet available there...
Tested with Mojarra 2.1.27 + Tomcat 6-7 & Mojarra 2.2.5 + Tomcat 7
As to the cause, UIComponent instances are inherently request scoped. The postback effectively creates a brand new instance with properties like values reinitialized to default. In your implementation, it is only filled during encodeXxx(), which is invoked long after decode() wherein the action event needs to be queued and thus too late.
You'd better fill it during the initialization of the component. If you want a #PostConstruct-like hook for UIComponent instances, then the postAddToView event is a good candidate. This is invoked directly after the component instance is added to the component tree.
<cc:implementation>
<f:event type="postAddToView" listener="#{cc.init}" />
...
</cc:implementation>
with
private List<String> values;
public void init() {
values = new ArrayList<String>();
Integer num = (Integer) getAttributes().get("value");
for (int i = 0; i < num; i++) {
values.add("item" + i);
}
}
(and remove the encodeBegin() method if it isn't doing anything useful anymore)
An alternative would be lazy initialization in getValues() method.
A simpler solution would be to store and retrieve values as part of the components state. Storing can happen during encodeBegin, and retrieving could directly happen within the getter:
#FacesComponent("components.myTable")
public class TestTable extends UINamingContainer {
public void action() {
System.out.println("Called");
}
#Override
public void encodeBegin(FacesContext context) throws IOException {
// Initialize the list according to the element number
List<String> values = new ArrayList<>();
Integer num = (Integer) getAttributes().get("itemNumber");
for (int i = 0; i < num; i++) {
values.add("item" + i);
}
getStateHelper().put("values",values);
super.encodeBegin(context);
}
public List<String> getValues() {
return (List<String>)getStateHelper().get("values");
}
}
To avoid repeating the logic in getValues(), there could be additional parsing required in more complex cases, there should be a way to process and cache the attributes right after they become available, although I am not sure when and how at this point.
Either way - this seemed to be the simplest way to solve this problem.

JSF passing large number of parameters from one page to other

I want to pass a large number of parameters from one JSF page to another.
For lower number of parameters I use ExternalContext#redirect() in an listener method with a url containing the parameters like this:
FacesContext.getCurrentInstance().getExternalContext().redirect("/faces/someDir/index.jsf?p1=a&p2=b");
If I do the same with large number of parameters it doesn't work. My understanding is, that the browser has a restriction on the size of the URL. If the URL has more tahn approx. 2000 characerts it doesn't work.
I tried a forward like
FacesContext.getCurrentInstance().getExternalContext().dispatch("/faces/someDir/index.jsf?p1=a&p2=b");
but then the target page works on the data of the source page. Reason for this could be the my software archticture, which I can not explain in detail here...
My questions: Has anyone had a similar problem and a solution for this?
If you want to send a large number of parameters accross more pages, then it's better to encapsulate them into a session scoped bean instead of sending them as GET parameters.
For example:
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
#ManagedBean
#SessionScoped
public class SESSION_Bean_Class {
// Declare members
// all parameters
private int p1;
private int p2;
private String p3;
private String p4;
// Getter(s) and Setter(s)
public int getP1() {
return p1;
}
public void setP1(int p1) {
this.p1 = p1;
}
public int getP2() {
return p2;
}
public void setP2(int p2) {
this.p2 = p2;
}
public String getP3() {
return p3;
}
public void setP3(String p3) {
this.p3 = p3;
}
public String getP4() {
return p4;
}
public void setP4(String p4) {
this.p4 = p4;
}
}
Then you can access them easily at any page like follows:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:a4j="http://richfaces.org/a4j"
xmlns:rich="http://richfaces.org/rich"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets">
</h:head>
<h:body>
Value parameter 1 is That #{sESSION_Bean_Class.p1}
<br />
Value parameter 2 is That #{sESSION_Bean_Class.p2}
<br />
Value parameter 3 is That #{sESSION_Bean_Class.p3}
<br />
Value parameter 4 is That #{sESSION_Bean_Class.p4}
<br />
</h:body>
</html>

Resources