defaultquery.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>
<DT><B>Parameters:</B><DD><CODE>query</CODE> - </DL>

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<B>Method Detail</B></FONT></TD>
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<A NAME="getPropertyNames()"><!-- --></A><H3>
getPropertyNames</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>[] <B>getPropertyNames</B>()</PRE>
<DL>
<DD>The property names is used to specify the attributes that should be
 selected for the return feature collection.  If the property array is
 null, then the datasource should return all available properties, its
 full schema.  If an array of  specified then the full schema should be
 used (all property names). The property names can be determined with a
 getSchema call from the DataSource interface.
 
 <p>
 This replaces our funky setSchema method of retrieving select
 properties.  I think it makes it easier to understand how to get
 certain properties out of the datasource, instead of having users get
 the  schema and then compose a new schema using the attributes that
 they want.  The old way was also giving me problems because I couldn't
 have multiple object reuse the same datasource object, since some other
 object could come along and change its schema, and would then return
 the wrong properties.
 </p>
 
 <p></p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getPropertyNames()">getPropertyNames</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the property names to be used in the returned FeatureCollection.</DL>
</DD>
</DL>
<HR>

<A NAME="setPropertyNames(java.lang.String[])"><!-- --></A><H3>
setPropertyNames</H3>
<PRE>
public void <B>setPropertyNames</B>(<A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>[]&nbsp;propNames)</PRE>
<DL>
<DD>Sets the properties to retrieve from the db.  If the boolean to load all
 properties is set to true then the AttributeTypes that are not in the
 database's schema will just be filled with null values.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>propNames</CODE> - The names of attributes to load from the datasouce.</DL>
</DD>
</DL>
<HR>

<A NAME="setPropertyNames(java.util.List)"><!-- --></A><H3>
setPropertyNames</H3>
<PRE>
public void <B>setPropertyNames</B>(<A HREF="http://java.sun.com/j2se/1.4/docs/api/java/util/List.html" title="class or interface in java.util">List</A>&nbsp;propNames)</PRE>
<DL>
<DD>Sets the proper attributeTypes constructed from a schema and a  list of
 propertyNames.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>propNames</CODE> - the names of the properties to check against the
        schema. If null then all attributes will be returned.  If a List
        of size 0 is used then only the featureIDs should be used.<DT><B>'TODO:'</B></DT>
  <DD>REVISIT: This syntax is really obscure.  Consider having an fid or
       featureID propertyName that datasource implementors look for
       instead of looking to see if the list size is 0.</DD>
</DL>
</DD>
</DL>
<HR>

<A NAME="retrieveAllProperties()"><!-- --></A><H3>
retrieveAllProperties</H3>
<PRE>
public boolean <B>retrieveAllProperties</B>()</PRE>
<DL>
<DD>Convenience method to determine if the query should use the full schema
 (all properties) of the data source for the features returned.  This
 method is equivalent to if (query.getProperties() == null), but allows
 for more clarity on the part of datasource implementors, so they do not
 need to examine and use null values.  All Query implementations should
 return true for this function if getProperties returns null.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#retrieveAllProperties()">retrieveAllProperties</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>if all datasource attributes should be included in the  schema
         of the returned FeatureCollection.</DL>
</DD>
</DL>
<HR>

<A NAME="getMaxFeatures()"><!-- --></A><H3>
getMaxFeatures</H3>
<PRE>
public int <B>getMaxFeatures</B>()</PRE>
<DL>
<DD>The optional maxFeatures can be used to limit the number of features
 that a query request retrieves.  If no maxFeatures is specified then
 all features should be returned.
 
 <p>
 This is the only method that is not directly out of the Query element in
 the WFS spec.  It is instead a part of a <code>getFeatures</code>
 request, which can hold one or more queries.  But each of those in turn
 will need a maxFeatures, so it is needed here.
 </p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getMaxFeatures()">getMaxFeatures</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the max features the getFeature call should return.</DL>
</DD>
</DL>
<HR>

<A NAME="setMaxFeatures(int)"><!-- --></A><H3>
setMaxFeatures</H3>
<PRE>
public void <B>setMaxFeatures</B>(int&nbsp;maxFeatures)</PRE>
<DL>
<DD>Sets the max features to retrieved by this query.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>maxFeatures</CODE> - the maximum number of features the getFeature call
        should return.</DL>
</DD>
</DL>
<HR>

<A NAME="getFilter()"><!-- --></A><H3>
getFilter</H3>
<PRE>
public <A HREF="../../../org/geotools/filter/Filter.html" title="interface in org.geotools.filter">Filter</A> <B>getFilter</B>()</PRE>
<DL>
<DD>The Filter can be used to define constraints on a query.  If no Filter
 is present then the query is unconstrained and all feature instances
 should be retrieved.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getFilter()">getFilter</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>The filter that defines constraints on the query.</DL>
</DD>
</DL>
<HR>

<A NAME="setFilter(org.geotools.filter.Filter)"><!-- --></A><H3>
setFilter</H3>
<PRE>
public void <B>setFilter</B>(<A HREF="../../../org/geotools/filter/Filter.html" title="interface in org.geotools.filter">Filter</A>&nbsp;filter)</PRE>
<DL>
<DD>Sets the filter to constrain the query.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>filter</CODE> - the OGC filter to limit the datasource getFeatures
        request.</DL>
</DD>
</DL>
<HR>

<A NAME="getTypeName()"><!-- --></A><H3>
getTypeName</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>getTypeName</B>()</PRE>
<DL>
<DD>The typeName attribute is used to indicate the name of the feature type
 to be queried.
 
 <p>
 The DataStore API does not assume one feature type per datastore.
 It currently makes use of this field to to specify with each request
 what type to get.
 </p>
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getTypeName()">getTypeName</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the name of the feature type to be returned with this query.</DL>
</DD>
</DL>
<HR>

<A NAME="getNamespace()"><!-- --></A><H3>
getNamespace</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/net/URI.html" title="class or interface in java.net">URI</A> <B>getNamespace</B>()</PRE>
<DL>
<DD><B>Description copied from interface: <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></B></DD>
<DD>The namespace attribute is used to indicate the namespace of the schema
 being represented.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getNamespace()">getNamespace</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the gml namespace of the feature type to be returned with this
         query</DL>
</DD>
</DL>
<HR>

<A NAME="setTypeName(java.lang.String)"><!-- --></A><H3>
setTypeName</H3>
<PRE>
public void <B>setTypeName</B>(<A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;typeName)</PRE>
<DL>
<DD>Sets the typename.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>typeName</CODE> - the name of the featureType to retrieve.</DL>
</DD>
</DL>
<HR>

<A NAME="getHandle()"><!-- --></A><H3>
getHandle</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>getHandle</B>()</PRE>
<DL>
<DD>The handle attribute is included to allow a client to associate  a
 mnemonic name to the Query request. The purpose of the handle attribute
 is to provide an error handling mechanism for locating  a statement
 that might fail.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../org/geotools/data/Query.html#getHandle()">getHandle</A></CODE> in interface <CODE><A HREF="../../../org/geotools/data/Query.html" title="interface in org.geotools.data">Query</A></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the mnemonic name of the query request.</DL>
</DD>
</DL>
<HR>

<A NAME="setHandle(java.lang.String)"><!-- --></A><H3>
setHandle</H3>
<PRE>
public void <B>setHandle</B>(<A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;handle)</PRE>
<DL>