datafeaturecollection.html

Geotools是一个开源的Java GIS工具包,可利用它来开发符合标准的地理信息系统。Geotools提供了OGC(Open Geospatial Consortium)规范的一个实现来作为他们的

 <p>
 The method getSchema() is named for compatability with the geotools 2.0 API. In the
 Geotools 2.2 time frame we should be able to replace this method with a careful check
 of getFeatureType() and its attributes.
  </p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html#getSchema()">getSchema</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html" title="interface in org.geotools.feature">FeatureCollection</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>FeatureType describing the "common" schema to all child features of this collection</DL>
</DD>
</DL>
<HR>

<A NAME="reader()"><!-- --></A><H3>
reader</H3>
<PRE>
public abstract <A HREF="../../../../org/geotools/data/FeatureReader.html" title="interface in org.geotools.data">FeatureReader</A> <B>reader</B>()
                              throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD><B>Description copied from interface: <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></B></DD>
<DD>Provides access to the Features, please note that FeatureReader is a
 blocking api.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/data/FeatureResults.html#reader()">reader</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>A FeatureReader streaming over the FeatureResults
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - DOCUMENT ME!</DL>
</DD>
</DL>
<HR>

<A NAME="getBounds()"><!-- --></A><H3>
getBounds</H3>
<PRE>
public abstract <A HREF="http://www.jump-project.org/docs/jts/1.7/api/com/vividsolutions/jts/geom/Envelope.html" title="class or interface in com.vividsolutions.jts.geom">Envelope</A> <B>getBounds</B>()</PRE>
<DL>
<DD><B>Description copied from interface: <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></B></DD>
<DD>Returns the bounding box of this FeatureResults.

 <p>
 This opperation may be expensive. Consider
 <code>FeatureSource.getBounds( Query )</code> as an alternative.
 </p>
 This method is logically the same as:
 <pre>
 <code>
 <b>public</b> Envelope getBounds() <b>throws</b> IOException {
     Envelope newBBox = <b>new</b> Envelope();
     Envelope internal;
     Feature feature;

     <b>for</b> (FeatureReader r = reader(); r.hasNext();) {
         feature = r.next();
         internal = feature.getDefaultGeometry().getEnvelopeInternal();
         newBBox.expandToInclude(internal);
     }
     <b>return</b> newBBox;
 }
 </code>
 </pre>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/data/FeatureResults.html#getBounds()">getBounds</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>Bounding box of this FeatureResults, or an empty Envelope</DL>
</DD>
</DL>
<HR>

<A NAME="getCount()"><!-- --></A><H3>
getCount</H3>
<PRE>
public abstract int <B>getCount</B>()
                      throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD><B>Description copied from interface: <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></B></DD>
<DD>Returns the number of Features in this FeatureResults.

 <p>
 This opperation may be expensive. Consider <code>FeatureSource.getCount(
 Query )</code> as an alternative.
 </p>
 This method is logically the same as:
 <pre>
 <code>
 <b>public</b> int getCount() <b>throws</b> IOException {
     <b>int</b> count = 0;
     <b>for</b> (FeatureReader r = reader(); r.hasNext(); count++) {
         r.next();
     }
     <b>return</b> count;
 }
 </code>
 </pre>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/data/FeatureResults.html#getCount()">getCount</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>The number of Features in this FeatureResults.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If there are problems getting the count</DL>
</DD>
</DL>
<HR>

<A NAME="collection()"><!-- --></A><H3>
collection</H3>
<PRE>
public abstract <A HREF="../../../../org/geotools/feature/FeatureCollection.html" title="interface in org.geotools.feature">FeatureCollection</A> <B>collection</B>()
                                      throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD><B>Description copied from interface: <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></B></DD>
<DD>Convert this set of results to a FeatureCollection.

 <p>
 This method is logically the same as:
 <pre><code>
 <b>public</b> FeatureCollection collection() <b>throws</b> IOException {
     FeatureCollection collection = FeatureCollections.newCollection()
     <b>for</b> (FeatureReader r = reader(); r.hasNext();) {
         collection.add( r.next() );
     }
     <b>return</b> collection;
 }
 </code></pre>
 </p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/data/FeatureResults.html#collection()">collection</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/data/FeatureResults.html" title="interface in org.geotools.data">FeatureResults</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>DOCUMENT ME!
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If any problems occur aquiring Features</DL>
</DD>
</DL>
<HR>

<A NAME="writer()"><!-- --></A><H3>
writer</H3>
<PRE>
protected <A HREF="../../../../org/geotools/data/FeatureWriter.html" title="interface in org.geotools.data">FeatureWriter</A> <B>writer</B>()
                        throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Subclass may provide an implementation of this method to indicate
 that read/write support is provided.
 <p>
 All operations that attempt to modify the "data" will
 use this method, allowing them to throw an "UnsupportedOperationException"
 in the same manner as Collections.unmodifiableCollection(Collection c)
 </p>
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/UnsupportedOperationException.html" title="class or interface in java.lang">UnsupportedOperationException</A></CODE> - To indicate that write support is not avaiable
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE></DL>
</DD>
</DL>
<HR>

<A NAME="addListener(org.geotools.feature.CollectionListener)"><!-- --></A><H3>
addListener</H3>
<PRE>
public void <B>addListener</B>(<A HREF="../../../../org/geotools/feature/CollectionListener.html" title="interface in org.geotools.feature">CollectionListener</A>&nbsp;listener)</PRE>
<DL>
<DD>Adds a listener for collection events.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html#addListener(org.geotools.feature.CollectionListener)">addListener</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html" title="interface in org.geotools.feature">FeatureCollection</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>listener</CODE> - The listener to add</DL>
</DD>
</DL>
<HR>

<A NAME="removeListener(org.geotools.feature.CollectionListener)"><!-- --></A><H3>
removeListener</H3>
<PRE>
public void <B>removeListener</B>(<A HREF="../../../../org/geotools/feature/CollectionListener.html" title="interface in org.geotools.feature">CollectionListener</A>&nbsp;listener)</PRE>
<DL>
<DD>Removes a listener for collection events.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html#removeListener(org.geotools.feature.CollectionListener)">removeListener</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html" title="interface in org.geotools.feature">FeatureCollection</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>listener</CODE> - The listener to remove</DL>
</DD>
</DL>
<HR>

<A NAME="features()"><!-- --></A><H3>
features</H3>
<PRE>
public <A HREF="../../../../org/geotools/feature/FeatureIterator.html" title="interface in org.geotools.feature">FeatureIterator</A> <B>features</B>()</PRE>
<DL>
<DD>FeatureIterator is entirely based on iterator().
 <p>
 So when we implement FeatureCollection.iterator() this will work
 out of the box.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html#features()">features</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/feature/FeatureCollection.html" title="interface in org.geotools.feature">FeatureCollection</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>A FeatureIterator.</DL>
</DD>
</DL>
<HR>

<A NAME="iterator()"><!-- --></A><H3>
iterator</H3>
<PRE>
public final <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/util/Iterator.html" title="class or interface in java.util">Iterator</A> <B>iterator</B>()</PRE>
<DL>
<DD>Iterator may (or may) not support modification.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/data/collection/ResourceCollection.html#iterator()">iterator</A></CODE> in interface <CODE><A HREF="../../../../org/geotools/data/collection/ResourceCollection.html" title="interface in org.geotools.data.collection">ResourceCollection</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>Iterator</DL>
</DD>
</DL>
<HR>

<A NAME="openIterator()"><!-- --></A><H3>
openIterator</H3>
<PRE>
protected <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/util/Iterator.html" title="class or interface in java.util">Iterator</A> <B>openIterator</B>()</PRE>
<DL>
<DD>Returns a FeatureWriterIterator, or FeatureReaderIterator over content.
 <p>
 If you have a way to tell that you are readonly please subclass with
 a less hardcore check - this implementations catches a
 UnsupportedOpperationsException from wrtier()!
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>