mapelresolver.html

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<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context of this evaluation.<DD><CODE>base</CODE> - The map to be modified. Only bases of type <code>Map</code>
     are handled by this resolver.<DD><CODE>property</CODE> - The key with which the specified value is to be
     associated.<DD><CODE>val</CODE> - The value to be associated with the specified key.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/ClassCastException.html" title="class or interface in java.lang">ClassCastException</A></CODE> - if the class of the specified key or 
     value prevents it from being stored in this map.
<DD><CODE><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/NullPointerException.html" title="class or interface in java.lang">NullPointerException</A></CODE> - if context is <code>null</code>, or if 
     this map does not permit <code>null</code> keys or values, and
     the specified key or value is <code>null</code>.
<DD><CODE><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/IllegalArgumentException.html" title="class or interface in java.lang">IllegalArgumentException</A></CODE> - if some aspect of this key or 
     value prevents it from being stored in this map.
<DD><CODE><A HREF="../../javax/el/ELException.html" title="class in javax.el">ELException</A></CODE> - if an exception was thrown while performing
     the property or variable resolution. The thrown exception
     must be included as the cause property of this exception, if
     available.
<DD><CODE><A HREF="../../javax/el/PropertyNotWritableException.html" title="class in javax.el">PropertyNotWritableException</A></CODE> - if this resolver was constructed
     in read-only mode, or if the put operation is not supported by 
     the underlying map.</DL>
</DD>
</DL>
<HR>

<A NAME="isReadOnly(javax.el.ELContext, java.lang.Object, java.lang.Object)"><!-- --></A><H3>
isReadOnly</H3>
<PRE>
public boolean <B>isReadOnly</B>(<A HREF="../../javax/el/ELContext.html" title="class in javax.el">ELContext</A>&nbsp;context,
                          <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;base,
                          <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;property)</PRE>
<DL>
<DD>If the base object is a map, returns whether a call to 
 <A HREF="../../javax/el/MapELResolver.html#setValue(javax.el.ELContext, java.lang.Object, java.lang.Object, java.lang.Object)"><CODE>setValue(javax.el.ELContext, java.lang.Object, java.lang.Object, java.lang.Object)</CODE></A> will always fail.

 <p>If the base is a <code>Map</code>, the <code>propertyResolved</code>
 property of the <code>ELContext</code> object must be set to
 <code>true</code> by this resolver, before returning. If this property
 is not <code>true</code> after this method is called, the caller 
 should ignore the return value.</p>

 <p>If this resolver was constructed in read-only mode, this method will
 always return <code>true</code>.</p>

 <p>If a <code>Map</code> was created using 
 <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/util/Collections.html#unmodifiableMap(java.util.Map)" title="class or interface in java.util"><CODE>Collections.unmodifiableMap(java.util.Map<? extends K, ? extends V>)</CODE></A>, this method must
 return <code>true</code>. Unfortunately, there is no Collections API
 method to detect this. However, an implementation can create a
 prototype unmodifiable <code>Map</code> and query its runtime type
 to see if it matches the runtime type of the base object as a 
 workaround.</p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../javax/el/ELResolver.html#isReadOnly(javax.el.ELContext, java.lang.Object, java.lang.Object)">isReadOnly</A></CODE> in class <CODE><A HREF="../../javax/el/ELResolver.html" title="class in javax.el">ELResolver</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context of this evaluation.<DD><CODE>base</CODE> - The map to analyze. Only bases of type <code>Map</code>
     are handled by this resolver.<DD><CODE>property</CODE> - The key to return the read-only status for.
     Ignored by this resolver.
<DT><B>Returns:</B><DD>If the <code>propertyResolved</code> property of 
     <code>ELContext</code> was set to <code>true</code>, then
     <code>true</code> if calling the <code>setValue</code> method
     will always fail or <code>false</code> if it is possible that
     such a call may succeed; otherwise undefined.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/NullPointerException.html" title="class or interface in java.lang">NullPointerException</A></CODE> - if context is <code>null</code>
<DD><CODE><A HREF="../../javax/el/ELException.html" title="class in javax.el">ELException</A></CODE> - if an exception was thrown while performing
     the property or variable resolution. The thrown exception
     must be included as the cause property of this exception, if
     available.</DL>
</DD>
</DL>
<HR>

<A NAME="getFeatureDescriptors(javax.el.ELContext, java.lang.Object)"><!-- --></A><H3>
getFeatureDescriptors</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/util/Iterator.html" title="class or interface in java.util">Iterator</A>&lt;<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/beans/FeatureDescriptor.html" title="class or interface in java.beans">FeatureDescriptor</A>&gt; <B>getFeatureDescriptors</B>(<A HREF="../../javax/el/ELContext.html" title="class in javax.el">ELContext</A>&nbsp;context,
                                                         <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;base)</PRE>
<DL>
<DD>If the base object is a map, returns an <code>Iterator</code>
 containing the set of keys available in the <code>Map</code>. 
 Otherwise, returns <code>null</code>.

 <p>The <code>Iterator</code> returned must contain zero or more 
 instances of <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/beans/FeatureDescriptor.html" title="class or interface in java.beans"><CODE>FeatureDescriptor</CODE></A>. Each info object 
 contains information about a key in the Map, and is initialized as 
 follows:
 <dl>
     <li>displayName - The return value of calling the 
         <code>toString</code> method on this key, or 
         <code>"null"</code> if the key is <code>null</code>.</li>
     <li>name - Same as displayName property.</li>
     <li>shortDescription - Empty string</li>
     <li>expert - <code>false</code></li>
     <li>hidden - <code>false</code></li>
     <li>preferred - <code>true</code></li>
 </dl>
 In addition, the following named attributes must be set in the
 returned <code>FeatureDescriptor</code>s:
 <dl>
     <li><A HREF="../../javax/el/ELResolver.html#TYPE"><CODE>ELResolver.TYPE</CODE></A> - The return value of calling the <code>getClass()</code>
         method on this key, or <code>null</code> if the key is
         <code>null</code>.</li>
     <li><A HREF="../../javax/el/ELResolver.html#RESOLVABLE_AT_DESIGN_TIME"><CODE>ELResolver.RESOLVABLE_AT_DESIGN_TIME</CODE></A> - <code>true</code></li>
 </dl>
 </p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../javax/el/ELResolver.html#getFeatureDescriptors(javax.el.ELContext, java.lang.Object)">getFeatureDescriptors</A></CODE> in class <CODE><A HREF="../../javax/el/ELResolver.html" title="class in javax.el">ELResolver</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context of this evaluation.<DD><CODE>base</CODE> - The map whose keys are to be iterated over. Only bases 
     of type <code>Map</code> are handled by this resolver.
<DT><B>Returns:</B><DD>An <code>Iterator</code> containing zero or more (possibly
     infinitely more) <code>FeatureDescriptor</code> objects, each
     representing a key in this map, or <code>null</code> if 
     the base object is not a map.<DT><B>See Also:</B><DD><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/beans/FeatureDescriptor.html" title="class or interface in java.beans"><CODE>FeatureDescriptor</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getCommonPropertyType(javax.el.ELContext, java.lang.Object)"><!-- --></A><H3>
getCommonPropertyType</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Class.html" title="class or interface in java.lang">Class</A>&lt;?&gt; <B>getCommonPropertyType</B>(<A HREF="../../javax/el/ELContext.html" title="class in javax.el">ELContext</A>&nbsp;context,
                                      <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;base)</PRE>
<DL>
<DD>If the base object is a map, returns the most general type that 
 this resolver accepts for the <code>property</code> argument.
 Otherwise, returns <code>null</code>.

 <p>Assuming the base is a <code>Map</code>, this method will always
 return <code>Object.class</code>. This is because <code>Map</code>s
 accept any object as a key.</p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../javax/el/ELResolver.html#getCommonPropertyType(javax.el.ELContext, java.lang.Object)">getCommonPropertyType</A></CODE> in class <CODE><A HREF="../../javax/el/ELResolver.html" title="class in javax.el">ELResolver</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context of this evaluation.<DD><CODE>base</CODE> - The map to analyze. Only bases of type <code>Map</code>
     are handled by this resolver.
<DT><B>Returns:</B><DD><code>null</code> if base is not a <code>Map</code>; otherwise
     <code>Object.class</code>.</DL>
</DD>
</DL>
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