null Long values displayed as 0
Dear all,
I just finished to struggle with the display of nullable Long or Integer
values. I am using Primefaces 5.0.1 / MyFaces 2.2.4 / OpenWebBeans 1.2.2
/ Tomcat 7.0.39.
Those values are the result of the evaluation of EL expressions that I
create with the following function :
public static ValueExpression createValueExpression(String
expression, Class clazz) {
FacesContext fc = FacesContext.getCurrentInstance();
ELContext elContext = fc.getELContext();
FacesELContext felContext = (FacesELContext)fc.getELContext();
SenatFunctionMapper sfm = SenatFunctionMapper.getInstance();
felContext.setFunctionMapper(sfm);
ExpressionFactory expFactory =
fc.getApplication().getExpressionFactory();
ValueExpression ret = null;
if(clazz==null) {
clazz = Object.class;
}
try {
ret = expFactory.createValueExpression(elContext,
expression, clazz);
} catch (ELException ex) {
log.fatal(Erreur de compilation de l'expression EL :
' + expression + ', ex);
}
return ret;
}
Until now, I created those value expressions with the real expected
class as the third parameter of ExpressionFactory#createValueExpression.
The name of this parameter is expectedType, so it seems logical to me
to provide the best information I had. So, I provided
java.lang.Integer.class or java.lang.Long.class, etc.
But when I do that, null values are displayed as 0, either with
h:inputText (standard MyFaces control) or p:inputText (PrimeFaces version).
The reason being that
org.apache.el.ValueExpressionImpl#getValue
is implemented the following way
@Override
public Object getValue(ELContext context) throws
PropertyNotFoundException,
ELException {
EvaluationContext ctx = new EvaluationContext(context,
this.fnMapper,
this.varMapper);
Object value = this.getNode().getValue(ctx);
if (this.expectedType != null) {
return ELSupport.coerceToType(value, this.expectedType);
}
return value;
}
and that ELSupport.coerceToType of a Long or Integer null value is
defined as... 0
As those type are numeric, coerceToType calls coerceToNumber, which
starts with :
public static final Number coerceToNumber(final Object obj,
final Class? type) throws ELException {
if (obj == null || .equals(obj)) {
return coerceToNumber(ZERO, type);
}
...
}
thus, the ZERO value.
For the time being, I solved my «problem» by passing a null third
parameter to ExpressionFactory#createValueExpression. It works. It has
no apparent drawbacks. But I don't get the logic of it. Should'nt
ELSupport#coerceToNumber handles this differently ?
Thanks in advance for your explanations,
Ludovic
|
| AVANT D'IMPRIMER, PENSEZ A L'ENVIRONNEMENT.
|
Re: null Long values displayed as 0
Maybe you could try to add property
org.apache.el.parser.COERCE_TO_ZERO=false to your JVM
Denis/MTL
2014-07-16 13:00 GMT-04:00 l.pe...@senat.fr l.pe...@senat.fr:
Dear all,
I just finished to struggle with the display of nullable Long or Integer
values. I am using Primefaces 5.0.1 / MyFaces 2.2.4 / OpenWebBeans 1.2.2 /
Tomcat 7.0.39.
Those values are the result of the evaluation of EL expressions that I
create with the following function :
public static ValueExpression createValueExpression(String expression,
Class clazz) {
FacesContext fc = FacesContext.getCurrentInstance();
ELContext elContext = fc.getELContext();
FacesELContext felContext = (FacesELContext)fc.getELContext();
SenatFunctionMapper sfm = SenatFunctionMapper.getInstance();
felContext.setFunctionMapper(sfm);
ExpressionFactory expFactory = fc.getApplication().
getExpressionFactory();
ValueExpression ret = null;
if(clazz==null) {
clazz = Object.class;
}
try {
ret = expFactory.createValueExpression(elContext,
expression, clazz);
} catch (ELException ex) {
log.fatal(Erreur de compilation de l'expression EL : ' +
expression + ', ex);
}
return ret;
}
Until now, I created those value expressions with the real expected class
as the third parameter of ExpressionFactory#createValueExpression. The
name of this parameter is expectedType, so it seems logical to me to
provide the best information I had. So, I provided java.lang.Integer.class
or java.lang.Long.class, etc.
But when I do that, null values are displayed as 0, either with
h:inputText (standard MyFaces control) or p:inputText (PrimeFaces version).
The reason being that
org.apache.el.ValueExpressionImpl#getValue
is implemented the following way
@Override
public Object getValue(ELContext context) throws
PropertyNotFoundException,
ELException {
EvaluationContext ctx = new EvaluationContext(context,
this.fnMapper,
this.varMapper);
Object value = this.getNode().getValue(ctx);
if (this.expectedType != null) {
return ELSupport.coerceToType(value, this.expectedType);
}
return value;
}
and that ELSupport.coerceToType of a Long or Integer null value is defined
as... 0
As those type are numeric, coerceToType calls coerceToNumber, which starts
with :
public static final Number coerceToNumber(final Object obj,
final Class? type) throws ELException {
if (obj == null || .equals(obj)) {
return coerceToNumber(ZERO, type);
}
...
}
thus, the ZERO value.
For the time being, I solved my «problem» by passing a null third
parameter to ExpressionFactory#createValueExpression. It works. It has no
apparent drawbacks. But I don't get the logic of it. Should'nt
ELSupport#coerceToNumber handles this differently ?
Thanks in advance for your explanations,
Ludovic
|
| AVANT D'IMPRIMER, PENSEZ A L'ENVIRONNEMENT.
|
Re: null Long values displayed as 0
On 16/07/2014 19:15, titou10 titou10 wrote: Maybe you could try to add property org.apache.el.parser.COERCE_TO_ZERO=false to your JVM Denis/MTL No, COERCE_TO_ZERO is useful in the opposite way, when submitting the value. BTW, I already use it. Thx anyway. Ludovic | | AVANT D'IMPRIMER, PENSEZ A L'ENVIRONNEMENT. |
Re: null Long values displayed as 0
Hi All files from org.apache.el comes from the EL library, so it is out of MyFaces scope. I think you cannot override the EL coercion rules, unless you change the underlying EL library. regards, Leonardo 2014-07-16 12:20 GMT-05:00 l.pe...@senat.fr l.pe...@senat.fr: On 16/07/2014 19:15, titou10 titou10 wrote: Maybe you could try to add property org.apache.el.parser.COERCE_TO_ZERO=false to your JVM Denis/MTL No, COERCE_TO_ZERO is useful in the opposite way, when submitting the value. BTW, I already use it. Thx anyway. Ludovic | | AVANT D'IMPRIMER, PENSEZ A L'ENVIRONNEMENT. |
