WebRowSet JDK 1.6)

Description

public interface WebRowSet

The standard interface that all implementations of a WebRowSet must implement.

1.0 Overview

The WebRowSetImpl provides the standard reference implementation, which may be extended if required.

The standard WebRowSet XML Schema definition is available at the following URI:

 http://java.sun.com/xml/ns/jdbc/webrowset.xsd

It describes the standard XML document format required when describing a RowSet object in XML and must be used be all standard implementations of the WebRowSet interface to ensure interoperability. In addition, the WebRowSet schema uses specific SQL/XML Schema annotations, thus ensuring greater cross platform inter-operability. This is an effort currently under way at the ISO organization. The SQL/XML definition is available at the following URI:

 http://standards.iso.org/iso/9075/2002/12/sqlxml

The schema definition describes the internal data of a RowSet object in three distinct areas:

properties

RowSet

metadata

WebRowSet

java.sql.ResultSet

data

WebRowSet

2.0 WebRowSet States

The following sections demonstrates how a WebRowSet implementation should use the XML Schema to describe update, insert, and delete operations and to describe the state of a WebRowSet object in XML.

2.1 State 1 - Outputting a `WebRowSet` Object to XML

In this example, a WebRowSet object is created and populated with a simple 2 column, 5 row table from a data source. Having the 5 rows in a WebRowSet object makes it possible to describe them in XML. The metadata describing the various standard JavaBeans properties as defined in the RowSet interface plus the standard properties defined in the CachedRowSet^TM interface provide key details that describe WebRowSet properties. Outputting the WebRowSet object to XML using the standard writeXml methods describes the internal properties as follows:

 <properties>
       <command>select co1, col2 from test_table</command>
        <concurrency>1</concurrency>
        <datasource/>
        <escape-processing>true</escape-processing>
        <fetch-direction>0</fetch-direction>
        <fetch-size>0</fetch-size>
        <isolation-level>1</isolation-level>
        <key-columns/>
        <map/>
        <max-field-size>0</max-field-size>
        <max-rows>0</max-rows>
        <query-timeout>0</query-timeout>
        <read-only>false</read-only>
        <rowset-type>TRANSACTION_READ_UNCOMMITED</rowset-type>
        <show-deleted>false</show-deleted>
        <table-name/>
        <url>jdbc:thin:oracle</url>
        <sync-provider>
                <sync-provider-name>.com.rowset.provider.RIOptimisticProvider</sync-provider-name>
                <sync-provider-vendor>Sun Microsystems</sync-provider-vendor>
                <sync-provider-version>1.0</sync-provider-name>
                <sync-provider-grade>LOW</sync-provider-grade>
              <data-source-lock>NONE</data-source-lock>
        </sync-provider>
 </properties>

The meta-data describing the make up of the WebRowSet is described in XML as detailed below. Note both columns are described between the column-definition tags.

 <metadata>
        <column-count>2</column-count>
        <column-definition>
                <column-index>1</column-index>
                <auto-increment>false</auto-increment>
                <case-sensitive>true</case-sensitive>
                <currency>false</currency>
                <nullable>1</nullable>
                <signed>false</signed>
                <searchable>true</searchable>
                <column-display-size>10</column-display-size>   
                <column-label>COL1</column-label>
                <column-name>COL1</column-name>
                <schema-name/>
                <column-precision>10</column-precision>
                <column-scale>0</column-scale>
                <table-name/>
                <catalog-name/>
                <column-type>1</column-type>
                <column-type-name>CHAR</column-type-name>
        </column-definition>
        <column-definition>
                <column-index>2</column-index>
                <auto-increment>false</auto-increment>
                <case-sensitive>false</case-sensitive>
                <currency>false</currency>
                <nullable>1</nullable>
                <signed>true</signed>
                <searchable>true</searchable>
                <column-display-size>39</column-display-size>
                <column-label>COL2</column-label>
                <column-name>COL2</column-name>
                <schema-name/>
                <column-precision>38</column-precision>
                <column-scale>0</column-scale>
                <table-name/>
                <catalog-name/>
                <column-type>3</column-type>
                <column-type-name>NUMBER</column-type-name>
        </column-definition>
 </metadata>

Having detailed how the properties and metadata are described, the following details how the contents of a WebRowSet object is described in XML. Note, that this describes a WebRowSet object that has not undergone any modifications since its instantiation. A currentRow tag is mapped to each row of the table structure that the WebRowSet object provides. A columnValue tag may contain either the stringData or binaryData tag, according to the SQL type that the XML value is mapping back to. The binaryData tag contains data in the Base64 encoding and is typically used for BLOB and CLOB type data.

 <data>
        <currentRow>
                <columnValue>
                        firstrow
                </columnValue>
                <columnValue>
                        1
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        secondrow
                </columnValue>
                <columnValue>
                        2
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        thirdrow
                </columnValue>
                <columnValue>
                        3
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        fourthrow
                </columnValue>
                <columnValue>
                        4
                </columnValue>
        </currentRow>
 </data>

2.2 State 2 - Deleting a Row

Deleting a row in a WebRowSet object involves simply moving to the row to be deleted and then calling the method deleteRow, as in any other RowSet object. The following two lines of code, in which wrs is a WebRowSet object, delete the third row.

     wrs.absolute(3);
     wrs.deleteRow();

The XML description shows the third row is marked as a deleteRow, which eliminates the third row in the WebRowSet object.

 <data>
        <currentRow>
                <columnValue>
                        firstrow
                </columnValue>
                <columnValue>
                        1
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        secondrow
                </columnValue>
                <columnValue>
                        2
                </columnValue>
        </currentRow>
        <deleteRow>
                <columnValue>
                        thirdrow
                </columnValue>
                <columnValue>
                        3
                </columnValue>
        </deleteRow>
        <currentRow>
                <columnValue>
                        fourthrow
                </columnValue>
                <columnValue>
                        4
                </columnValue>
        </currentRow>
 </data>

2.3 State 3 - Inserting a Row

A WebRowSet object can insert a new row by moving to the insert row, calling the appropriate updater methods for each column in the row, and then calling the method insertRow.

 wrs.moveToInsertRow();
 wrs.updateString(1, "fifththrow");
 wrs.updateString(2, "5");
 wrs.insertRow();

The following code fragment changes the second column value in the row just inserted. Note that this code applies when new rows are inserted right after the current row, which is why the method next moves the cursor to the correct row. Calling the method acceptChanges writes the change to the data source.

 wrs.moveToCurrentRow();
 wrs.next();
 wrs.updateString(2, "V");
 wrs.acceptChanges();
 :

Describing this in XML demonstrates where the Java code inserts a new row and then performs an update on the newly inserted row on an individual field.

 
 <data>
        <currentRow>
                <columnValue>
                        firstrow
                </columnValue>
                <columnValue>
                        1
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        secondrow
                </columnValue>
                <columnValue>
                        2
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        newthirdrow
                </columnValue>
                <columnValue>
                        III
                </columnValue>
        </currentRow>
        <insertRow>
                <columnValue>
                        fifthrow
                </columnValue>
                <columnValue>
                        5
                </columnValue>
                <updateValue>
                        V
                </updateValue>
        </insertRow>
        <currentRow>
                <columnValue>
                        fourthrow
                </columnValue>
                <columnValue>
                        4
                </columnValue>
        </currentRow>
 </date>

2.4 State 4 - Modifying a Row

Modifying a row produces specific XML that records both the new value and the value that was replaced. The value that was replaced becomes the original value, and the new value becomes the current value. The following code moves the cursor to a specific row, performs some modifications, and updates the row when complete.

 wrs.absolute(5);
 wrs.updateString(1, "new4thRow");
 wrs.updateString(2, "IV");
 wrs.updateRow();

In XML, this is described by the modifyRow tag. Both the original and new values are contained within the tag for original row tracking purposes.

 <data>
        <currentRow>
                <columnValue>
                        firstrow
                </columnValue>
                <columnValue>
                        1
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        secondrow
                </columnValue>
                <columnValue>
                        2
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        newthirdrow
                </columnValue>
                <columnValue>
                        III
                </columnValue>
        </currentRow>
        <currentRow>
                <columnValue>
                        fifthrow
                </columnValue>
                <columnValue>
                        5
                </columnValue>
        </currentRow>
        <modifyRow>
                <columnValue>
                        fourthrow
                </columnValue>
                <updateValue>
                        new4thRow
                </updateValue>
                <columnValue>
                        4
                </columnValue>
                <updateValue>
                        IV
                </updateValue>
        </modifyRow>
 </data>

See also: JdbcRowSet CachedRowSet FilteredRowSet JoinRowSet

Methods

Hide/Show inherited methods

public void readXml (InputStream iStream) throws SQLException IOException

Reads a stream based XML input to populate this WebRowSet object.

Reads a stream based XML input to populate this WebRowSet
object.
Parameters:
- iStream - the java.io.InputStream from which this WebRowSet object will be populated
Throws:
- SQLException - if a data source access error occurs
- IOException - if an IO exception occurs

public void readXml (Reader reader) throws SQLException

Reads a WebRowSet object in its XML format from the given Reader object.

Reads a WebRowSet object in its XML format from the given
Reader object.
Parameters:
- reader - the java.io.Reader stream from which this WebRowSet object will be populated
Throws:
- SQLException - if a database access error occurs

public void writeXml (OutputStream oStream) throws SQLException IOException

Writes the data, properties, and metadata for this WebRowSet object to the given OutputStream object in XML format.

Writes the data, properties, and metadata for this WebRowSet object
to the given OutputStream object in XML format.
Parameters:
- oStream - the java.io.OutputStream stream to write to
Throws:
- SQLException - if a data source access error occurs
- IOException - if a IO exception occurs

public void writeXml (ResultSet rs, OutputStream oStream) throws SQLException IOException

Populates this WebRowSet object with the contents of the given ResultSet object and writes its data, properties, and metadata to the given OutputStream object in XML format.

NOTE: The WebRowSet cursor may be moved to write out the contents to the XML data source. If implemented in this way, the cursor must be returned to its position just prior to the writeXml() call.
Parameters:
- rs - the ResultSet object with which to populate this WebRowSet object
- oStream - the java.io.OutputStream to write to
Throws:
- SQLException - if a data source access error occurs
- IOException - if a IO exception occurs

public void writeXml (ResultSet rs, Writer writer) throws SQLException

Populates this WebRowSet object with the contents of the given ResultSet object and writes its data, properties, and metadata to the given Writer object in XML format.

NOTE: The WebRowSet cursor may be moved to write out the contents to the XML data source. If implemented in this way, the cursor must be returned to its position just prior to the writeXml() call.
Parameters:
- rs - the ResultSet object with which to populate this WebRowSet object
- writer - the java.io.Writer object to write to.
Throws:
- SQLException - if an error occurs writing out the rowset contents in XML format

public void writeXml (Writer writer) throws SQLException

Writes the data, properties, and metadata for this WebRowSet object to the given Writer object in XML format.

Writes the data, properties, and metadata for this WebRowSet object
to the given Writer object in XML format.
Parameters:
- writer - the java.io.Writer stream to write to
Throws:
- SQLException - if an error occurs writing out the rowset contents to XML

Fields

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publicfinalstatic int CLOSE_CURSORS_AT_COMMIT = "2" [Inherited From CachedRowSet]

The constant indicating that open ResultSet objects with this holdability will be closed when the current transaction is commited.

The constant indicating that open ResultSet objects with this
holdability will be closed when the current transaction is commited.
Since: 1.4

publicfinalstatic boolean COMMIT_ON_ACCEPT_CHANGES = "true" [Inherited From CachedRowSet]

Causes the CachedRowSet object's SyncProvider to commit the changes when acceptChanges() is called.

Causes the CachedRowSet object's SyncProvider
to commit the changes when acceptChanges() is called. If
set to false, the changes will not be committed until one of the
CachedRowSet interface transaction methods is called.
See Also: CachedRowSet.commit(), CachedRowSet.rollback(),

publicfinalstatic int CONCUR_READ_ONLY = "1007" [Inherited From CachedRowSet]

The constant indicating the concurrency mode for a ResultSet object that may NOT be updated.

The constant indicating the concurrency mode for a
ResultSet object that may NOT be updated.
Since: 1.2

publicfinalstatic int CONCUR_UPDATABLE = "1008" [Inherited From CachedRowSet]

The constant indicating the concurrency mode for a ResultSet object that may be updated.

The constant indicating the concurrency mode for a
ResultSet object that may be updated.
Since: 1.2

publicfinalstatic int FETCH_FORWARD = "1000" [Inherited From CachedRowSet]

The constant indicating that the rows in a result set will be processed in a forward direction; first-to-last.

The constant indicating that the rows in a result set will be
processed in a forward direction; first-to-last.
This constant is used by the method setFetchDirection
as a hint to the driver, which the driver may ignore.
Since: 1.2

publicfinalstatic int FETCH_REVERSE = "1001" [Inherited From CachedRowSet]

The constant indicating that the rows in a result set will be processed in a reverse direction; last-to-first.

The constant indicating that the rows in a result set will be
processed in a reverse direction; last-to-first.
This constant is used by the method setFetchDirection
as a hint to the driver, which the driver may ignore.
Since: 1.2

publicfinalstatic int FETCH_UNKNOWN = "1002" [Inherited From CachedRowSet]

The constant indicating that the order in which rows in a result set will be processed is unknown.

The constant indicating that the order in which rows in a
result set will be processed is unknown.
This constant is used by the method setFetchDirection
as a hint to the driver, which the driver may ignore.

publicfinalstatic int HOLD_CURSORS_OVER_COMMIT = "1" [Inherited From CachedRowSet]

The constant indicating that open ResultSet objects with this holdability will remain open when the current transaction is commited.

The constant indicating that open ResultSet objects with this
holdability will remain open when the current transaction is commited.
Since: 1.4

publicfinalstatic String PUBLIC_XML_SCHEMA = "--//Sun Microsystems, Inc.//XSD Schema//EN"

The public identifier for the XML Schema definition that defines the XML tags and their valid values for a WebRowSet implementation.

publicfinalstatic String SCHEMA_SYSTEM_ID = "http://java.sun.com/xml/ns/jdbc/webrowset.xsd"

The URL for the XML Schema definition file that defines the XML tags and their valid values for a WebRowSet implementation.

publicfinalstatic int TYPE_FORWARD_ONLY = "1003" [Inherited From CachedRowSet]

The constant indicating the type for a ResultSet object whose cursor may move only forward.

The constant indicating the type for a ResultSet object
whose cursor may move only forward.
Since: 1.2

publicfinalstatic int TYPE_SCROLL_INSENSITIVE = "1004" [Inherited From CachedRowSet]

The constant indicating the type for a ResultSet object that is scrollable but generally not sensitive to changes to the data that underlies the ResultSet.

The constant indicating the type for a ResultSet object
that is scrollable but generally not sensitive to changes to the data
that underlies the ResultSet.
Since: 1.2

publicfinalstatic int TYPE_SCROLL_SENSITIVE = "1005" [Inherited From CachedRowSet]

The constant indicating the type for a ResultSet object that is scrollable and generally sensitive to changes to the data that underlies the ResultSet.