Re: HELP: about to get datasource of struts and pass to logic bea ns...

[Vic Cekvenich <ce...@basebeans.com>]

Ah a small comment... The Struts DataSource should not be used, I agree;
  the J2EE container DataSource should be used; but it will not be 
removed for a while AFIAK.

(Deprecated just means it might be removed in some futre version. Just 
like hopefully bean, logic and html:link get deprecated in 2.0 in favor 
of JSTL. It's just a nudge from developers (of which I am not one) for 
you to start considering the better alternatives. I even think Java 
should deprecate Connection , ResultSet and java.util.Date  in favor of 
DataSource, RowSet and Calendar)
Poolman is very, very nice... I used it before 2001; when I switched to 
RowSet (before I started using a SQL based DAO). DAO is best thing to do 
now, and all the DB issues would disapper.

.V


Edgar P Dollin wrote:
> Don't spend the time to get DataSource working.  It is deprecated and will
> be removed from struts in 1.2.  I use Poolman at sourceforge (I highly
> reccomend it for non-j2ee projects).  Most others use the DataSource
> supplied with the container.
> 
> Edgar
> 
> -----Original Message-----
> From: Caroline Jen [mailto:jiapei_jen@yahoo.com]
> Sent: Monday, December 08, 2003 4:29 PM
> To: Struts Users Mailing List
> Subject: Re: HELP: about to get datasource of struts and pass to logic
> beans...
> 
> 
> There are lots of classes involved.  I will give you
> an example:
> 
> 1. my LogonAction calls EditorService.java (business
> delegate)
> 2. EditorService.java calls MySQLEditorDAO.java (data
> access object implements EditorDAO.java, which is a
> data access interface)
> 3. the MySQLEditorDAO.java returns EditorBean.java (a
> Java bean with three properties)
> 
> Here is my LogonAction.java:
> 
> package org.apache.artimus.logon;
> 
> import java.io.IOException;
> import javax.servlet.ServletException;
> import javax.servlet.http.HttpServletRequest;
> import javax.servlet.http.HttpSession;
> import javax.servlet.http.HttpServletResponse;
> import org.apache.struts.action.Action;
> import org.apache.struts.action.ActionError;
> import org.apache.struts.action.ActionErrors;
> import org.apache.struts.action.ActionForm;
> import org.apache.struts.action.ActionForward;
> import org.apache.struts.action.ActionMapping;
> import org.apache.struts.action.ActionServlet;
> 
> import org.apache.artimus.lang.Tokens;
> 
> public final class LogonAction extends Action {
> 
>     public ActionForward execute(ActionMapping
> mapping,
>             ActionForm form,
>             HttpServletRequest request,
>             HttpServletResponse response)
>         throws java.lang.Exception {
>         
>         // Obtain username and password from web tier
>         String username = ((LogonForm)
> form).getUsername();
>         String password = ((LogonForm)
> form).getPassword();
>         
>         EditorService service = new EditorService();
>         EditorBean editor = service.findEditorData(
> username );
> 
>         HttpSession session = request.getSession();
>         session.setAttribute( "editor", editor );
> 
>         // Log this event, if appropriate
> 
>         if (servlet.getDebug() >= Tokens.DEBUG) {
>             StringBuffer message =
>                 new StringBuffer("LogonAction: User
> '");
>             message.append(username);
>             message.append("' logged on in session ");
>             message.append(session.getId());
>             servlet.log(message.toString());
>         }
> 
>         // Return success
>         return (mapping.findForward(Tokens.VALID));
> 
>     }
> 
> } // End LogonAction
> 
> Here is the EditorService.java:
> 
> package org.apache.artimus.logon;
> 
> import org.apache.artimus.logon.dao.*;
> 
> public class EditorService 
> {
>    EditorDAO ed = new MySQLEditorDAO();
>    public EditorBean findEditorData( String username )
>    {    
>       return ed.findEditor( username );
>    }
> }
> 
> Here is the EditorDAO.java:
> 
> package org.apache.artimus.logon.dao;
> 
> import org.apache.artimus.logon.EditorBean;
> import
> org.apache.artimus.logon.exceptions.EditorDAOSysException;
> 
> public interface EditorDAO.java
> {
>     public EditorBean findEditor( String username )
>         throws EditorDAOSysException;
> }
> 
> Here is the MySQLEditorDAO.java:
> 
> package org.apache.artimus.logon.dao;
> 
> import java.io.IOException;
> import java.sql.Connection;
> import java.sql.ResultSet;
> import java.sql.Statement;
> import java.sql.SQLException;
> 
> import org.apache.artimus.logon.EditorBean;
> import
> org.apache.artimus.logon.exceptions.EditorDAOSysException;
> import org.apache.artimus.ConnectionPool.DBConnection;
> 
> public class MySQLEditorDAO implements EditorDAO
> {
>    // Here the return type is EditorBean
>    public EditorBean findEditor( String username ) 
>        throws EditorDAOSysException 
>    {
>       Connection conn = null;
>       Statement stmt = null;
>       ResultSet rs = null;
> 
>       try 
>       {
>          conn = DBConnection.getDBConnection();
>          stmt = conn.createStatement();
>          String query = "SELECT user_role,
> journal_category FROM members WHERE user_name = '" +
> username + "'";   
>          rs = stmt.executeQuery( query );
>          if (rs.next()) 
>          {
>             return new EditorBean( username,
> rs.getString( "user_role" ), rs.getString(
> "journal_category" ) );
>          }
>          else
>          {
>             System.out.println( "invalid user name" );
>             return null;            
>          }
>       } 
>       catch (SQLException se)
>       {
>          throw new
> EditorDAOSysException("SQLException: " +
> se.getMessage());
>       }
>       finally
>       {
>          if ( conn != null )
>          {
>             try
>             {
>                rs.close();
>                rs = null;
>                stmt.close();
>                stmt = null;
>                conn.close();
>             }
>             catch( SQLException sqlEx )
>             {
>                System.out.println( "Problem occurs
> while closing " + sqlEx );
>             }
>             conn = null;
>          }       
>       }
>    }
> }
> 
> Here is the EditorBean.java:
> 
> package org.apache.artimus.logon;
> 
> import org.apache.artimus.logon.dao.*;
> 
> public class EditorBean {
> 
>    private String username;
>    private String userrole;
>    private String keyValue;
> 
>    static EditorDAO ed = new MySQLEditorDAO();
> 
>    public EditorBean() {}
>    public EditorBean( String username, String
> userrole, String keyValue )
>    {
>       setUsername( username );
>       setUserrole( userrole );
>       setKeyValue( keyValue );
>    }
>    public String getUsername() {
>       return username;
>    }
>    public void setUsername( String username ) {
>       this.username = username;
>    }
>    public String getUserrole() {
>       return userrole;
>    }
>    public void setUserrole( String userrole ) {
>       this.userrole = userrole;
>    }
>    public String getKeyValue() {
>       return keyValue;
>    }
>    public void setKeyValue( String keyValue ) {
>       this.keyValue = keyValue;
>    }
> }
> 
> Here is the DBConnection.java, which gets a connection
> object from a connection pool (you have to configure
> your server's connection pool):
> 
> package org.apache.artimus.ConnectionPool;
> 
> import java.sql.Connection;
> import java.sql.SQLException;
> import javax.naming.InitialContext;
> import javax.naming.NamingException;
> import javax.sql.DataSource;
> 
> public class DBConnection 
> {
>    public static Connection getDBConnection() throws
> SQLException
>    {
>       Connection conn = null;
> 
>       try
>       {
>          InitialContext ctx = new InitialContext();
>          DataSource ds = ( DataSource ) ctx.lookup(
> "java:comp/env/jdbc/MySQLDB" );
> 
>          try 
>          {
>             conn = ds.getConnection();
>          }
>          catch( SQLException e )
>          {  
>             System.out.println( "Open connection
> failure: " + e.getMessage() );
>          }
>       }
>       catch( NamingException nEx )
>       {
>          nEx.printStackTrace();
>       }
>       return conn;
>    }
> }
> 
> Here is the exception handling class:
> 
> package org.apache.artimus.logon.exceptions;
> 
> /**
>  * EditorDAOSysException is an exception that extends
> the standard
>  * RunTimeException Exception. This is thrown by the
> DAOs of the article
>  * component when there is some irrecoverable error
> (like SQLException)
>  */
> 
> public class EditorDAOSysException extends
> RuntimeException {
> 
>     /**
>      * Constructor
>      * @param str    a string that explains what the
> exception condition is
>      */
>     public EditorDAOSysException (String str) {
>         super(str);
>     } 
> 
>     /**
>      * Default constructor. Takes no arguments
>      */
>     public EditorDAOSysException () {
>         super();
>     }
> }
> 
> -Caroline
> --- Ricky <Ri...@hotmail.com> wrote:
> 
>>hi, there, 
>>
>>    with my project i had several queries about get
>>datasource in struts. i know how to get datasource
>>in struts, just as in myAction, use getDataSource
>>method and return DataSource object, and go on to
>>get connection .... 
>>
>>    i also know the logic beans between the
>>Controller and Module, so i create a logic bean ,i
>>don't know how to get datasourc of pass the
>>datasource, in some tutorial , i got a way to solve
>>this, create a method getDAO(HttpServletRequest
>>request) and pass the request to the method to get
>>DataSource, i was lost here, i dont' know what
>>should i return in getDAO, should i return a
>>DataSource object or others and in my logic bean i
>>can use the datasource and also get connection ,
>>statement and resultset object , there i have to
>>close it after i finish my process ....what do you
>>think of this i did ? in general, when i got a
>>DataSource, i will got a connection from datasource
>>and a PrepareStatement and also a ResultSet , when i
>>finished my process, i can close all object i opened
>>before in final method of try
>>...catch...experession.. now what should i do to
>>return a proper object in getDAO method and in logic
>>beans i can use the object to process logic
>>business...
>>
>>i appologized for this ... i hope you can give me
>>some suggestion or flow...... thanx!
>>
>>now here is my flow of struts framework to pass the
>>datasource to the logic beans...  i hope you can
>>reword if you have some good idea...of correct my
>>mistake... :)
>>
>>    myAction :
>>
>>    myAction extends Action() {
>>      public ActionForward execute(ActionMapping
>>mapping,
>>                               ActionForm form,
>>                               HttpServletRequest
>>request,
>>                               HttpServletResponse
>>response) {
>>        LogicBean bean = new LogicBean();
>>        Object objcet =
>>bean.doMethod(getDAO(request), other param)
>>      }
>>      
>>      public DataSource getDAO(HttpServletRequest
>>request) {
>>        DataSource ds = null;
>>        ds = getDataSource(request);
>>        return ds;
>>      }
>>    }
>>
>>    and in my logic bean :
>>
>>    class LogicBean {
>>      public Objct doMethod(DataSource ds, other
>>param) {
>>        try {
>>          Connection conn = ds.getConnection();
>>          PrepareStatment stmt =
>>conn.prepareStatment("SELECT .......");
>>          stmt.setInt(1,....);
>>          ResultSet rs = stmt.executeQuery();
>>          ....
>>          return Object.....;
>>        } catch (SQLException ex) {
>>          ex.printStactTrace();
>>        } final {
>>          try {
>>            rs.close();
>>            stmt.close();
>>            conn.close()
>>          } catch (Exception ex) {
>>            ex.printStactTrace();
>>          }
>>        }
>>        return null;
>>      }
>>    }
>>
>>    should i pass the DataSource to my logic beans?
>>otherwise what object should i pass....
>>
>>
>>
>>
>>
>>
> 
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> 
> 
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