<!DOCTYPE doctype PUBLIC "-//w3c//dtd html 4.0 transitional//en"><html><head>                  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">                  <meta name="GENERATOR" content="Mozilla/4.79 [en] (Windows NT 5.0; U) [Netscape]"><!--Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. This code is free software; you can redistribute it and/or modify itunder the terms of the GNU General Public License version 2 only, aspublished by the Free Software Foundation.  Oracle designates thisparticular file as subject to the "Classpath" exception as providedby Oracle in the LICENSE file that accompanied this code. This code is distributed in the hope that it will be useful, but WITHOUTANY WARRANTY; without even the implied warranty of MERCHANTABILITY orFITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public Licenseversion 2 for more details (a copy is included in the LICENSE file thataccompanied this code). You should have received a copy of the GNU General Public License version2 along with this work; if not, write to the Free Software Foundation,Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USAor visit www.oracle.com if you need additional information or have anyquestions.--><title>javax.sql.rowset.serial</title></head><body bgcolor="#ffffff">Provides utility classes to allow serializable mappings between SQL typesand data types in the Java programming language.<p> Standard JDBC <code>RowSet</code> implementations may use these utility classes toassist in the serialization of disconnected <code>RowSet</code> objects. This is usefulwhen  transmitting a disconnected <tt>RowSet</tt> object over the wire toa different VM or across layers within an application.<br></p> <h3>1.0 SerialArray</h3>A serializable mapping in the Java programming language of an SQL ARRAY value. <br><br>The <tt>SerialArray </tt>class provides a constructor for creating a <tt>SerialArray</tt>instance from an Array object, methods for getting the base type andthe SQL name for the base type, and methods for copying all or part of a<tt>SerialArray </tt>object. <br> <h3>2.0 SerialBlob</h3>A serializable mapping in the Java programming language of an SQL BLOBvalue.  <br><br>The <tt>SerialBlob </tt>class provides a constructor for creating an instancefrom a Blob object. Note that the Blob object should have brought the SQLBLOB value's data over to the client before a <tt>SerialBlob </tt>objectis constructed from it. The data of an SQL BLOB value can be materializedon the client as an array of bytes (using the method <tt>Blob.getBytes</tt>)or as a stream of uninterpreted bytes (using the method <tt>Blob.getBinaryStream</tt>).<br><br><tt>SerialBlob </tt>methods make it possible to make a copy of a <tt>SerialBlob</tt>object as an array of bytes or as a stream. They also make it possibleto locate a given pattern of bytes or a <tt>Blob </tt>object within a <tt>SerialBlob</tt>object. <br> <h3>3.0 SerialClob</h3>A serializable mapping in the Java programming language of an SQL CLOBvalue.  <br><br>The <tt>SerialClob </tt>class provides a constructor for creating an instancefrom a <tt>Clob </tt>object. Note that the <tt>Clob </tt>object should havebrought the SQL CLOB value's data over to the client before a <tt>SerialClob</tt>object is constructed from it. The data of an SQL CLOB value can bematerialized on the client as a stream of Unicode characters. <br><br><tt>SerialClob </tt>methods make it possible to get a substring from a <tt>SerialClob </tt>object or to locate the start of a pattern of characters. <br> <h3>5.0 SerialDatalink</h3>A serializable mapping in the Java programming language of an SQL DATALINKvalue. A DATALINK value references a file outside of the underlying data sourcethat the the originating data source manages. <br><br><code>RowSet</code> implementations can use the method <tt>RowSet.getURL() </tt>to retrievea <code>java.net.URL</code> object, which can be used to manipulate the external data.<br><br>&nbsp;&nbsp;<tt>&nbsp;&nbsp;&nbsp; java.net.URL url = rowset.getURL(1);</tt><br> <h3>6.0 SerialJavaObject</h3>A serializable mapping in the Java programming language of an SQL JAVA_OBJECTvalue. Assuming the Java object instance implements the Serializable interface,this simply wraps the serialization process. <br><br>If however, the serialization is not possible in the case where the Javaobject is not immediately serializable, this class will attempt to serializeall non static members to permit the object instance state to be serialized.Static or transient fields cannot be serialized and attempting to do so will result in a <tt>SerialException </tt>being thrown. <br> <h3>7.0 SerialRef</h3>A serializable mapping between the SQL REF type and the Java programminglanguage. <br><br>The <tt>SerialRef </tt>class provides a constructor for creating a <tt>SerialRef</tt>instance from a <tt>Ref</tt> type and provides methods for gettingand setting the <tt>Ref</tt> object type. <br> <h3>8.0 SerialStruct</h3>A serializable mapping in the Java programming language of an SQL structuredtype. Each attribute that is not already serializable is mapped to a serializableform, and if an attribute is itself a structured type, each of its attributesthat is not already serializable is mapped to a serializable form. <br><br>In addition, if a <code>Map</code> object is passed to one of the constructors orto the method <code>getAttributes</code>, the structured type is custom mapped according to the mapping specified in the <code>Map</code> object.  <br>  The <tt>SerialStruct </tt>class provides a constructor for creating aninstance  from a <tt>Struct</tt> object, a method for retrieving the SQLtype name of the SQL structured type in the database, and methods for retrievingits attribute values. <br>   <h3>9.0 SQLInputImpl</h3>  An input stream used for custom mapping user-defined types (UDTs). An   <tt>SQLInputImpl</tt> object is an input stream that contains a stream of   values that arethe attributes of a UDT. This class is used by the driver behind the sceneswhen the method <tt>getObject</tt> is called on an SQL structured or distincttype that has a custom mapping; a programmer never invokes <tt>SQLInputImpl</tt> methods directly. <br>  <br>  The <tt>SQLInputImpl</tt> class provides a set of reader methods analogous to the <tt>ResultSet</tt> getter methods. These methods make it possible to read the values in an <tt>SQLInputImpl</tt> object. The method<code>wasNull</code> is used to determine whether the the last value read was SQL NULL. <br>  <br>  When a constructor or getter method that takes a <code>Map</code> object is called, the JDBC driver calls the method<tt>SQLData.getSQLType</tt> to determine the SQL type of the UDT being custommapped. The driver  creates an instance of <code>SQLInputImpl</code>, populating it withthe attributes of  the UDT. The driver then passes the input stream to themethod <tt>SQLData.readSQL</tt>,  which in turn calls the <tt>SQLInputImpl</tt>methods to read the  attributes from the input stream. <br>   <h3>10.0 SQLOutputImpl</h3>  The output stream for writing the attributes of a custom mapped user-defined type (UDT) back to the database. The driver uses this interface internally, and its methods are never directly invoked by an application programmer.<br>  <br>  When an application calls the method <tt>PreparedStatement.setObject, </tt>the driver checks to see whether the value to be written is a UDT with a custom mapping. If it is, there will be an entry in a type map containing the Class object for the class that implements <tt>SQLData </tt>for this UDT. If the value to be written is an instance of <tt>SQLData</tt>, the driver willcreate  an instance of <code>SQLOutputImpl</code> and pass it to the method <tt>SQLData.writeSQL</tt>. The method <code>writeSQL</code> in turn calls the appropriate <tt>SQLOutputImpl</tt>writer methods to write data from the <code>SQLData</code> object to the <code>SQLOutputImpl</code>output  stream as the representation of an SQL user-defined type.          <h3>Custom Mapping</h3>The JDBC API provides mechanisms for mapping an SQL structured type or DISTINCT type to the Java programming language.  Typically, a structured type is mapped to a class, and its attributes are mapped to fields in the class.(A DISTINCT type can thought of as having one attribute.)  However, there aremany other possibilities, and there may be any number of different mappings.<P>A programmer defines the mapping by implementing the interface <code>SQLData</code>.For example, if an SQL structured type named AUTHORS has the attributes NAME,TITLE, and PUBLISHER, it could be mapped to a Java class named Authors.  TheAuthors class could have the fields name, title, and publisher, to which theattributes of AUTHORS are mapped.  In such a case, the implementation of <code>SQLData</code> could look like the following:<PRE>   public class Authors implements SQLData {       public String name;       public String title;       public String publisher;        private String sql_type;       public String getSQLTypeName() {           return sql_type;       }        public void readSQL(SQLInput stream, String type)                                  throws SQLException  {           sql_type = type;           name = stream.readString();           title = stream.readString();           publisher = stream.readString();       }        public void writeSQL(SQLOutput stream) throws SQLException {           stream.writeString(name);           stream.writeString(title);           stream.writeString(publisher);       }   } </PRE> A <code>java.util.Map</code> object is used to associate the SQL structuredtype with its mapping to the class <code>Authors</code>. The following code fragment showshow a <code>Map</code> object might be created and given an entry associating<code>AUTHORS</code> and <code>Authors</code>.  <PRE>    java.util.Map map = new java.util.HashMap();    map.put("SCHEMA_NAME.AUTHORS", Class.forName("Authors");</PRE> The <code>Map</code> object <i>map</i> now contains an entry with the fully qualified name of the SQL structured type and the <code>Class</code> object for the class <code>Authors</code>.  It can be passed to a methodto tell the driver how to map <code>AUTHORS</code> to <code>Authors</code>.  <P>For a disconnected <code>RowSet</code> object, custom mapping can be doneonly when a <code>Map</code> object is passed to the method or constructorthat will be doing the custom mapping.  The situation is different forconnected <code>RowSet</code> objects because they maintain a connectionwith the data source.  A method that does custom mapping and is called by a disconnected <code>RowSet</code> object may use the <code>Map</code>object that is associated with the <code>Connection</code> object beingused. So, in other words, if no map is specified, the connection's type map can be used by default.     <br></body></html>