BeanELResolverpublic class BeanELResolver extends ELResolver | Defines property resolution behavior on objects using the JavaBeans
component architecture.
This resolver handles base objects of any type, as long as the
base is not null. It accepts any object as a property, and
coerces it to a string. That string is then used to find a JavaBeans
compliant property on the base object. The value is accessed using
JavaBeans getters and setters.
This resolver can be constructed in read-only mode, which means that
{@link #isReadOnly} will always return true and
{@link #setValue} will always throw
PropertyNotWritableException.
ELResolvers are combined together using
{@link CompositeELResolver}s, to define rich semantics for evaluating
an expression. See the javadocs for {@link ELResolver} for details.
Because this resolver handles base objects of any type, it should
be placed near the end of a composite resolver. Otherwise, it will
claim to have resolved a property before any resolvers that come after
it get a chance to test if they can do so as well. |
| Fields Summary |
|---|
| private boolean | isReadOnly | | private static final int | CACHE_SIZE | | private static final ConcurrentHashMap | properties |
| Constructors Summary |
|---|
public BeanELResolver()Creates a new read/write BeanELResolver.
this.isReadOnly = false;
| public BeanELResolver(boolean isReadOnly)Creates a new BeanELResolver whose read-only status is
determined by the given parameter.
this.isReadOnly = isReadOnly;
|
| Methods Summary |
|---|
| private javax.el.BeanELResolver$BeanProperty | getBeanProperty(javax.el.ELContext context, java.lang.Object base, java.lang.Object prop)
String property = prop.toString();
Class baseClass = base.getClass();
BeanProperties bps = properties.get(baseClass);
if (bps == null) {
bps = new BeanProperties(baseClass);
properties.putIfAbsent(baseClass, bps);
}
BeanProperty bp = bps.getBeanProperty(property);
if (bp == null) {
throw new PropertyNotFoundException(
ELUtil.getExceptionMessageString(context,
"propertyNotFound",
new Object[] { baseClass.getName(),
property}));
}
return bp;
| | public java.lang.Class | getCommonPropertyType(javax.el.ELContext context, java.lang.Object base)If the base object is not null, returns the most
general type that this resolver accepts for the
property argument. Otherwise, returns null.
Assuming the base is not null, this method will always
return Object.class. This is because any object is
accepted as a key and is coerced into a string.
if (base == null){
return null;
}
return Object.class;
| | public java.util.Iterator | getFeatureDescriptors(javax.el.ELContext context, java.lang.Object base)If the base object is not null, returns an
Iterator containing the set of JavaBeans properties
available on the given object. Otherwise, returns null.
The Iterator returned must contain zero or more
instances of {@link java.beans.FeatureDescriptor}. Each info object
contains information about a property in the bean, as obtained by
calling the BeanInfo.getPropertyDescriptors method.
The FeatureDescriptor is initialized using the same
fields as are present in the PropertyDescriptor,
with the additional required named attributes "type" and
"resolvableAtDesignTime" set as follows:
{@link ELResolver#TYPE} - The runtime type of the property, from
PropertyDescriptor.getPropertyType().
{@link ELResolver#RESOLVABLE_AT_DESIGN_TIME} - true.
if (base == null){
return null;
}
BeanInfo info = null;
try {
info = Introspector.getBeanInfo(base.getClass());
} catch (Exception ex) {
}
if (info == null) {
return null;
}
ArrayList<FeatureDescriptor> list = new ArrayList<FeatureDescriptor>(
info.getPropertyDescriptors().length);
for (PropertyDescriptor pd: info.getPropertyDescriptors()) {
pd.setValue("type", pd.getPropertyType());
pd.setValue("resolvableAtDesignTime", Boolean.TRUE);
list.add(pd);
}
return list.iterator();
| | private static java.lang.reflect.Method | getMethod(java.lang.Class cl, java.lang.reflect.Method method)
if (method == null) {
return null;
}
if (Modifier.isPublic (cl.getModifiers ())) {
return method;
}
Class [] interfaces = cl.getInterfaces ();
for (int i = 0; i < interfaces.length; i++) {
Class c = interfaces[i];
Method m = null;
try {
m = c.getMethod(method.getName(), method.getParameterTypes());
c = m.getDeclaringClass();
if ((m = getMethod(c, m)) != null)
return m;
} catch (NoSuchMethodException ex) {
}
}
Class c = cl.getSuperclass();
if (c != null) {
Method m = null;
try {
m = c.getMethod(method.getName(), method.getParameterTypes());
c = m.getDeclaringClass();
if ((m = getMethod(c, m)) != null)
return m;
} catch (NoSuchMethodException ex) {
}
}
return null;
| | public java.lang.Class | getType(javax.el.ELContext context, java.lang.Object base, java.lang.Object property)If the base object is not null, returns the most
general acceptable type that can be set on this bean property.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. If this property is not true after this
method is called, the caller should ignore the return value.
The provided property will first be coerced to a String.
If there is a BeanInfoProperty for this property and
there were no errors retrieving it, the propertyType of
the propertyDescriptor is returned. Otherwise, a
PropertyNotFoundException is thrown.
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null){
return null;
}
BeanProperty bp = getBeanProperty(context, base, property);
context.setPropertyResolved(true);
return bp.getPropertyType();
| | public java.lang.Object | getValue(javax.el.ELContext context, java.lang.Object base, java.lang.Object property)If the base object is not null, returns the current
value of the given property on this bean.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. If this property is not true after this
method is called, the caller should ignore the return value.
The provided property name will first be coerced to a
String. If the property is a readable property of the
base object, as per the JavaBeans specification, then return the
result of the getter call. If the getter throws an exception,
it is propagated to the caller. If the property is not found or is
not readable, a PropertyNotFoundException is thrown.
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null){
return null;
}
BeanProperty bp = getBeanProperty(context, base, property);
Method method = bp.getReadMethod();
if (method == null) {
throw new PropertyNotFoundException(
ELUtil.getExceptionMessageString(context,
"propertyNotReadable",
new Object[] { base.getClass().getName(),
property.toString()}));
}
Object value;
try {
value = method.invoke(base, new Object[0]);
context.setPropertyResolved(true);
} catch (ELException ex) {
throw ex;
} catch (InvocationTargetException ite) {
throw new ELException(ite.getCause());
} catch (Exception ex) {
throw new ELException(ex);
}
return value;
| | public boolean | isReadOnly(javax.el.ELContext context, java.lang.Object base, java.lang.Object property)If the base object is not null, returns whether a call
to {@link #setValue} will always fail.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. If this property is not true after this
method is called, the caller can safely assume no value was set.
If this resolver was constructed in read-only mode, this method will
always return true.
The provided property name will first be coerced to a
String. If property is a writable property of
base, false is returned. If the property is
found but is not writable, true is returned. If the
property is not found, a PropertyNotFoundException
is thrown.
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null){
return false;
}
context.setPropertyResolved(true);
if (isReadOnly) {
return true;
}
BeanProperty bp = getBeanProperty(context, base, property);
return bp.isReadOnly();
| | private void | purgeBeanClasses(java.lang.ClassLoader classloader)
removeFromMap(properties, classloader);
| | private void | removeFromMap(java.util.Map map, java.lang.ClassLoader classloader)
Iterator<Class> iter = map.keySet().iterator();
while (iter.hasNext()) {
Class mbeanClass = iter.next();
if (classloader.equals(mbeanClass.getClassLoader())) {
iter.remove();
}
}
| | public void | setValue(javax.el.ELContext context, java.lang.Object base, java.lang.Object property, java.lang.Object val)If the base object is not null, attempts to set the
value of the given property on this bean.
If the base is not null, the
propertyResolved property of the ELContext
object must be set to true by this resolver, before
returning. If this property is not true after this
method is called, the caller can safely assume no value was set.
If this resolver was constructed in read-only mode, this method will
always throw PropertyNotWritableException.
The provided property name will first be coerced to a
String. If property is a writable property of
base (as per the JavaBeans Specification), the setter
method is called (passing value). If the property exists
but does not have a setter, then a
PropertyNotFoundException is thrown. If the property
does not exist, a PropertyNotFoundException is thrown.
if (context == null) {
throw new NullPointerException();
}
if (base == null || property == null){
return;
}
if (isReadOnly) {
throw new PropertyNotWritableException(
ELUtil.getExceptionMessageString(context,
"resolverNotwritable",
new Object[] { base.getClass().getName() }));
}
BeanProperty bp = getBeanProperty(context, base, property);
Method method = bp.getWriteMethod();
if (method == null) {
throw new PropertyNotWritableException(
ELUtil.getExceptionMessageString(context,
"propertyNotWritable",
new Object[] { base.getClass().getName(),
property.toString()}));
}
try {
method.invoke(base, new Object[] {val});
context.setPropertyResolved(true);
} catch (ELException ex) {
throw ex;
} catch (InvocationTargetException ite) {
throw new ELException(ite.getCause());
} catch (Exception ex) {
if (null == val) {
val = "null";
}
String message = ELUtil.getExceptionMessageString(context,
"setPropertyFailed",
new Object[] { property.toString(),
base.getClass().getName(), val });
throw new ELException(message, ex);
}
|
|
