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From: Mark P. <mar...@us...> - 2008-01-29 18:18:48
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Update of /cvsroot/springnet/Spring.Net/doc/reference/src In directory sc8-pr-cvs8.sourceforge.net:/tmp/cvs-serv6758 Modified Files: dbprovider.xml Log Message: SPRNET-858 - Added IDbProvider implementation, UserCredentialsDbProvider, to allow changing of username, password connection strings at runtime Index: dbprovider.xml =================================================================== RCS file: /cvsroot/springnet/Spring.Net/doc/reference/src/dbprovider.xml,v retrieving revision 1.17 retrieving revision 1.18 diff -C2 -d -r1.17 -r1.18 *** dbprovider.xml 24 Jan 2008 17:32:36 -0000 1.17 --- dbprovider.xml 29 Jan 2008 18:18:44 -0000 1.18 *************** *** 372,398 **** </section> ! <section> ! <title>MultiDelegatingDbProvider</title> ! <para>There are use-cases in which there will need to be a runtime ! selection of the database to connect to among many possible candidates. ! This is often the case where the same schema is installed in separate ! databases for different clients. The ! <classname>MultiDelegatingDbProvider</classname> implements the ! <classname>IDbProvider</classname> interface and provides an abstraction ! to the multiple databases and can be used in DAO layer such that the DAO ! layer is unaware of the switching between databases. ! <classname>MultiDelegatingDbProvider</classname> does its job by looking ! into thread local storage under the key dbProviderName. This storage ! location stores the name of the dbProvider that is to be used for ! processing the request. <classname>MultiDelegatingDbProvider</classname> ! is configured using the dictionary property ! <literal>TargetDbProviders</literal>. The key of this dictionary contains ! the name of a dbProvider and its value is a dbProvider object. During ! request processing, once you have determined which target dbProvider ! should be use, in this example database1ProviderName, you should execute ! the following code <literal>LogicalThreadContext.SetData("dbProviderName", ! "database1ProviderName")</literal> and then call the data access ! layer.</para> </section> </chapter> \ No newline at end of file --- 372,454 ---- </section> ! <section id="dbprovider-additional"> ! <title>Additional IDbProvider implementations</title> ! <para>Spring provides some convenient implementations of the IDbProvider ! interface that add addtional behavior on top of the standard ! implementation. </para> ! ! <section id="dbprovider-usercredentials"> ! <title>UserCredentialsDbProvider</title> ! ! <para>This <classname>UserCredentialsDbProvider</classname> will allow ! you to change the username and password of a database connection at ! runtime. The API contains the properties <literal>Username</literal> and ! <literal>Password</literal> which are used as the default strings ! representing the user and password in the connection string. You can ! then change the value of these properties in the connection string by ! calling the method <literal>SetCredentialsForCurrentThread</literal> and ! fall back to the default values by calling the method ! <literal>RemoveCredentialsFromCurrentThread</literal>. You call the ! <literal>SetCredentialsForCurrentThread</literal> method at runtime, ! before any data access occurs, to determine which database user should ! be used for the current user-case. Which user to select is up to you. ! You may retrieve the user information from an HTTP session for example. ! Example configuration and usage is shown below</para> ! ! <programlisting><object id="DbProvider" type="Spring.Data.Common.UserCredentialsDbProvider, Spring.Data"> ! <property name="TargetDbProvider" ref="targetDbProvider"/> ! <property name="Username" value="User ID=defaultName"/> ! <property name="Password" value="Password=defaultPass"/> ! </object> ! ! <db:provider id="targetDbProvider" provider="SqlServer-2.0" ! connectionString="Data Source=MARKT60\SQL2005;Database=Spring;Trusted_Connection=False"/></programlisting> ! ! <para>If you use dependency injection to configure a class with a ! property of the type <literal>IDbProvider</literal>, you will need to ! downcast to the subtype or you can change your class to have a property ! of the type <literal>UserCredentialsDbProvider</literal> instead of ! <literal>IDbProvider</literal>.</para> ! ! <programlisting>userCredentialsDbProvider.SetCredentialsForCurrentThread("User ID=springqa", "Password=springqa");</programlisting> ! ! <para><literal>UserCredentialsDbProvider's</literal> has a base class, ! <literal>DelegatingDbProvider</literal>, and is intended for you to use ! in your own implementations that delegate calls to a target ! <literal>IDbProvider</literal> instance. This class in meant to be ! subclassed with subclasses overriding only those methods, such as ! <literal>CreateConnection()</literal>, that should not simply delegate ! to the target <literal>IDbProvider</literal>.</para> ! </section> ! ! <section id="dbprovider-multidelegating"> ! <title>MultiDelegatingDbProvider</title> ! ! <para>There are use-cases in which there will need to be a runtime ! selection of the database to connect to among many possible candidates. ! This is often the case where the same schema is installed in separate ! databases for different clients. The ! <classname>MultiDelegatingDbProvider</classname> implements the ! <classname>IDbProvider</classname> interface and provides an abstraction ! to the multiple databases and can be used in DAO layer such that the DAO ! layer is unaware of the switching between databases. ! <classname>MultiDelegatingDbProvider</classname> does its job by looking ! into thread local storage under the key dbProviderName. This storage ! location stores the name of the dbProvider that is to be used for ! processing the request. <classname>MultiDelegatingDbProvider</classname> ! is configured using the dictionary property ! <literal>TargetDbProviders</literal>. The key of this dictionary ! contains the name of a dbProvider and its value is a dbProvider object. ! (You can also provide this dictionary as a constructor argument.) During ! request processing, once you have determined which target dbProvider ! should be use, in this example database1ProviderName, you should execute ! the following code ! <literal>LogicalThreadContext.SetData("dbProviderName", ! "database1ProviderName")</literal> and then call the data access ! layer.</para> ! ! <para></para> ! </section> </section> </chapter> \ No newline at end of file |
