How to display a 2d array of elements - jsf-2

Question

I'd like to display 2d array of floats in a table on a xhtml page using JSF2 and I have no idea how to do that. I tried to find the answer in google but I couldn't. All examples were displaying classes objects and I was not able to make it working with the table.
The sitation is:
I have the array of some size - the size of the array depends on entered data:
float [][] variables = new float[size1][size2]
After user enters data and pressess button a method is called in the managed bean. The calculation begins and the table is filled with data.
Please tell me how can I display the array.

Answer 1

To achieve that you can use c:forEach tag to dinamically buid a h:panelGrid. Just save size2, which is the column number as a property and store all the input numbers in a normal java.util.List. Then you set that size to the h:panelGrid columns attribute and the component will split the rows for you. You can also style the content inside the c:forEach tag, bordering it in order to give it a table behaviour.
<h:form>
<h:panelGrid columns="#{bean.numberCount}">
<c:forEach var="num" items="#{bean.numberList}">
#{number}
</c:forEach>
</h:panelGrid>
</h:form>
EDITED
If you want to maintain the original structure but in a List, you can create a List<List<Float>>. That means a List which is composed by List which contains Float Objects. The same as a 2d array.
private List<List<Float>> _Matrix;
public List<List<Float>> get_Matrix() {
return this._Matrix;
}
/**
* Constructor for BackingBean.
*/
public BackingBean() {
this._Matrix = new ArrayList<List<Float>>();
this._Matrix.add(new ArrayList<Float>());
this._Matrix.add(new ArrayList<Float>());
this._Matrix.get(0).add(1.0f);
this._Matrix.get(0).add(2.0f);
this._Matrix.get(0).add(3.0f);
this._Matrix.get(1).add(1.0f);
this._Matrix.get(1).add(2.0f);
this._Matrix.get(1).add(3.0f);
}
In the code above I'm constructing the equivalent to a 2d array with 2 rows and values 1.0,2.0 and 3.0 on each row. You can use this code to iterate it over the view:
<h:panelGrid columns="#{backingBean._ColumnNumber}">
<c:forEach var="row" items="#{backingBean._Matrix}">
<c:forEach var="value" items="#{row}">
#{value}
</c:forEach>
</c:forEach>
</h:panelGrid>
Where #{backingBean._ColumnNumber} will be the length of the first array of the List (supposing all of them have the same length).
Good Luck.