map.html

API資料大全

<DL>
<DD>Returns the number of key-value mappings in this map.  If the
 map contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
 <tt>Integer.MAX_VALUE</tt>.<DD><DL>
<DT><B>Returns:</B><DD>the number of key-value mappings in this map.</DL>
</DD>
</DL>
<HR>

<A NAME="isEmpty()"><!-- --></A><H3>
isEmpty</H3>
<PRE>
public boolean <B>isEmpty</B>()</PRE>
<DL>
<DD>Returns <tt>true</tt> if this map contains no key-value mappings.<DD><DL>
<DT><B>Returns:</B><DD><tt>true</tt> if this map contains no key-value mappings.</DL>
</DD>
</DL>
<HR>

<A NAME="containsKey(java.lang.Object)"><!-- --></A><H3>
containsKey</H3>
<PRE>
public boolean <B>containsKey</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;key)</PRE>
<DL>
<DD>Returns <tt>true</tt> if this map contains a mapping for the specified
 key.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>key</CODE> - key whose presence in this map is to be tested.<DT><B>Returns:</B><DD><tt>true</tt> if this map contains a mapping for the specified
 key.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/ClassCastException.html">ClassCastException</A></CODE> - if the key is of an inappropriate type for
 		  this map.<DD><CODE><A HREF="../../java/lang/NullPointerException.html">NullPointerException</A></CODE> - if the key is <tt>null</tt> and this map
            does not not permit <tt>null</tt> keys.</DL>
</DD>
</DL>
<HR>

<A NAME="containsValue(java.lang.Object)"><!-- --></A><H3>
containsValue</H3>
<PRE>
public boolean <B>containsValue</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;value)</PRE>
<DL>
<DD>Returns <tt>true</tt> if this map maps one or more keys to the
 specified value.  More formally, returns <tt>true</tt> if and only if
 this map contains at least one mapping to a value <tt>v</tt> such that
 <tt>(value==null ? v==null : value.equals(v))</tt>.  This operation
 will probably require time linear in the map size for most
 implementations of the <tt>Map</tt> interface.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>value</CODE> - value whose presence in this map is to be tested.<DT><B>Returns:</B><DD><tt>true</tt> if this map maps one or more keys to the
         specified value.</DL>
</DD>
</DL>
<HR>

<A NAME="get(java.lang.Object)"><!-- --></A><H3>
get</H3>
<PRE>
public <A HREF="../../java/lang/Object.html">Object</A> <B>get</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;key)</PRE>
<DL>
<DD>Returns the value to which this map maps the specified key.  Returns
 <tt>null</tt> if the map contains no mapping for this key.  A return
 value of <tt>null</tt> does not <i>necessarily</i> indicate that the
 map contains no mapping for the key; it's also possible that the map
 explicitly maps the key to <tt>null</tt>.  The <tt>containsKey</tt>
 operation may be used to distinguish these two cases.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>key</CODE> - key whose associated value is to be returned.<DT><B>Returns:</B><DD>the value to which this map maps the specified key, or
	       <tt>null</tt> if the map contains no mapping for this key.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/ClassCastException.html">ClassCastException</A></CODE> - if the key is of an inappropriate type for
 		  this map.<DD><CODE><A HREF="../../java/lang/NullPointerException.html">NullPointerException</A></CODE> - key is <tt>null</tt> and this map does not
		  not permit <tt>null</tt> keys.<DT><B>See Also: </B><DD><A HREF="../../java/util/Map.html#containsKey(java.lang.Object)"><CODE>containsKey(Object)</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="put(java.lang.Object, java.lang.Object)"><!-- --></A><H3>
put</H3>
<PRE>
public <A HREF="../../java/lang/Object.html">Object</A> <B>put</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;key,
                  <A HREF="../../java/lang/Object.html">Object</A>&nbsp;value)</PRE>
<DL>
<DD>Associates the specified value with the specified key in this map
 (optional operation).  If the map previously contained a mapping for
 this key, the old value is replaced.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>key</CODE> - key with which the specified value is to be associated.<DD><CODE>value</CODE> - value to be associated with the specified key.<DT><B>Returns:</B><DD>previous value associated with specified key, or <tt>null</tt>
	       if there was no mapping for key.  A <tt>null</tt> return can
	       also indicate that the map previously associated <tt>null</tt>
	       with the specified key, if the implementation supports
	       <tt>null</tt> values.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/UnsupportedOperationException.html">UnsupportedOperationException</A></CODE> - if the <tt>put</tt> operation is
	          not supported by this map.<DD><CODE><A HREF="../../java/lang/ClassCastException.html">ClassCastException</A></CODE> - if the class of the specified key or value
 	          prevents it from being stored in this map.<DD><CODE><A HREF="../../java/lang/IllegalArgumentException.html">IllegalArgumentException</A></CODE> - if some aspect of this key or value
	          prevents it from being stored in this map.<DD><CODE><A HREF="../../java/lang/NullPointerException.html">NullPointerException</A></CODE> - this map does not permit <tt>null</tt>
            keys or values, and the specified key or value is
            <tt>null</tt>.</DL>
</DD>
</DL>
<HR>

<A NAME="remove(java.lang.Object)"><!-- --></A><H3>
remove</H3>
<PRE>
public <A HREF="../../java/lang/Object.html">Object</A> <B>remove</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;key)</PRE>
<DL>
<DD>Removes the mapping for this key from this map if present (optional
 operation).<DD><DL>
<DT><B>Parameters:</B><DD><CODE>key</CODE> - key whose mapping is to be removed from the map.<DT><B>Returns:</B><DD>previous value associated with specified key, or <tt>null</tt>
	       if there was no mapping for key.  A <tt>null</tt> return can
	       also indicate that the map previously associated <tt>null</tt>
	       with the specified key, if the implementation supports
	       <tt>null</tt> values.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/UnsupportedOperationException.html">UnsupportedOperationException</A></CODE> - if the <tt>remove</tt> method is
         not supported by this map.</DL>
</DD>
</DL>
<HR>

<A NAME="putAll(java.util.Map)"><!-- --></A><H3>
putAll</H3>
<PRE>
public void <B>putAll</B>(<A HREF="../../java/util/Map.html">Map</A>&nbsp;t)</PRE>
<DL>
<DD>Copies all of the mappings from the specified map to this map
 (optional operation).  These mappings will replace any mappings that
 this map had for any of the keys currently in the specified map.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>t</CODE> - Mappings to be stored in this map.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/UnsupportedOperationException.html">UnsupportedOperationException</A></CODE> - if the <tt>putAll</tt> method is
 		  not supported by this map.<DD><CODE><A HREF="../../java/lang/ClassCastException.html">ClassCastException</A></CODE> - if the class of a key or value in the
 	          specified map prevents it from being stored in this map.<DD><CODE><A HREF="../../java/lang/IllegalArgumentException.html">IllegalArgumentException</A></CODE> - some aspect of a key or value in the
	          specified map prevents it from being stored in this map.<DD><CODE><A HREF="../../java/lang/NullPointerException.html">NullPointerException</A></CODE> - this map does not permit <tt>null</tt>
            keys or values, and the specified key or value is
            <tt>null</tt>.</DL>
</DD>
</DL>
<HR>

<A NAME="clear()"><!-- --></A><H3>
clear</H3>
<PRE>
public void <B>clear</B>()</PRE>
<DL>
<DD>Removes all mappings from this map (optional operation).<DD><DL>
<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/UnsupportedOperationException.html">UnsupportedOperationException</A></CODE> - clear is not supported by this
 		  map.</DL>
</DD>
</DL>
<HR>

<A NAME="keySet()"><!-- --></A><H3>
keySet</H3>
<PRE>
public <A HREF="../../java/util/Set.html">Set</A> <B>keySet</B>()</PRE>
<DL>
<DD>Returns a set view of the keys contained in this map.  The set is
 backed by the map, so changes to the map are reflected in the set, and
 vice-versa.  If the map is modified while an iteration over the set is
 in progress, the results of the iteration are undefined.  The set
 supports element removal, which removes the corresponding mapping from
 the map, via the <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
 <tt>removeAll</tt> <tt>retainAll</tt>, and <tt>clear</tt> operations.
 It does not support the add or <tt>addAll</tt> operations.<DD><DL>
<DT><B>Returns:</B><DD>a set view of the keys contained in this map.</DL>
</DD>
</DL>
<HR>

<A NAME="values()"><!-- --></A><H3>
values</H3>
<PRE>
public <A HREF="../../java/util/Collection.html">Collection</A> <B>values</B>()</PRE>
<DL>
<DD>Returns a collection view of the values contained in this map.  The
 collection is backed by the map, so changes to the map are reflected in
 the collection, and vice-versa.  If the map is modified while an
 iteration over the collection is in progress, the results of the
 iteration are undefined.  The collection supports element removal,
 which removes the corresponding mapping from the map, via the
 <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
 <tt>removeAll</tt>, <tt>retainAll</tt> and <tt>clear</tt> operations.
 It does not support the add or <tt>addAll</tt> operations.<DD><DL>
<DT><B>Returns:</B><DD>a collection view of the values contained in this map.</DL>
</DD>
</DL>
<HR>

<A NAME="entrySet()"><!-- --></A><H3>
entrySet</H3>
<PRE>
public <A HREF="../../java/util/Set.html">Set</A> <B>entrySet</B>()</PRE>
<DL>
<DD>Returns a set view of the mappings contained in this map.  Each element
 in the returned set is a <tt>Map.Entry</tt>.  The set is backed by the
 map, so changes to the map are reflected in the set, and vice-versa.
 If the map is modified while an iteration over the set is in progress,
 the results of the iteration are undefined.  The set supports element
 removal, which removes the corresponding mapping from the map, via the
 <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, <tt>removeAll</tt>,
 <tt>retainAll</tt> and <tt>clear</tt> operations.  It does not support
 the <tt>add</tt> or <tt>addAll</tt> operations.<DD><DL>
<DT><B>Returns:</B><DD>a set view of the mappings contained in this map.</DL>
</DD>
</DL>
<HR>

<A NAME="equals(java.lang.Object)"><!-- --></A><H3>
equals</H3>
<PRE>
public boolean <B>equals</B>(<A HREF="../../java/lang/Object.html">Object</A>&nbsp;o)</PRE>
<DL>
<DD>Compares the specified object with this map for equality.  Returns
 <tt>true</tt> if the given object is also a map and the two Maps
 represent the same mappings.  More formally, two maps <tt>t1</tt> and
 <tt>t2</tt> represent the same mappings if
 <tt>t1.entrySet().equals(t2.entrySet())</tt>.  This ensures that the
 <tt>equals</tt> method works properly across different implementations
 of the <tt>Map</tt> interface.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/lang/Object.html#equals(java.lang.Object)">equals</A></CODE> in class <CODE><A HREF="../../java/lang/Object.html">Object</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>o</CODE> - object to be compared for equality with this map.<DT><B>Returns:</B><DD><tt>true</tt> if the specified object is equal to this map.</DL>
</DD>
</DL>
<HR>

<A NAME="hashCode()"><!-- --></A><H3>
hashCode</H3>
<PRE>
public int <B>hashCode</B>()</PRE>
<DL>
<DD>Returns the hash code value for this map.  The hash code of a map
 is defined to be the sum of the hashCodes of each entry in the map's
 entrySet view.  This ensures that <tt>t1.equals(t2)</tt> implies
 that <tt>t1.hashCode()==t2.hashCode()</tt> for any two maps
 <tt>t1</tt> and <tt>t2</tt>, as required by the general
 contract of Object.hashCode.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/lang/Object.html#hashCode()">hashCode</A></CODE> in class <CODE><A HREF="../../java/lang/Object.html">Object</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the hash code value for this map.<DT><B>See Also: </B><DD><A HREF="../../java/util/Map.Entry.html#hashCode()"><CODE>Map.Entry.hashCode()</CODE></A>, 
<A HREF="../../java/lang/Object.html#hashCode()"><CODE>Object.hashCode()</CODE></A>, 
<A HREF="../../java/lang/Object.html#equals(java.lang.Object)"><CODE>Object.equals(Object)</CODE></A>, 
<A HREF="../../java/util/Map.html#equals(java.lang.Object)"><CODE>equals(Object)</CODE></A></DL>
</DD>
</DL>
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