threaddao.java

一个功能较为完善的论坛

package org.redsoft.forum.dao;

/**
 * Forum's DAO interface
 *
 * @author Charles Huang
 * @since JDK 1.4
 * @version 1.0
 */
import org.redsoft.forum.dao.PersistentThread;
import org.redsoft.forum.exception.CategoryNotFoundException;
import org.redsoft.forum.exception.ThreadNotFoundException;

import java.sql.SQLException;
import java.util.Collection;

public interface ThreadDAO{

    /**
     *  Add a new thread to the DB
     */
    public PersistentThread addThread( final PersistentThread thread ) throws SQLException;

    /**
     *  Remove a new thread from the DB
     */
    public void removeThread( final PersistentThread thread ) throws SQLException;

    /**
     *  Get all the top-level threads under the given category
     *
     *  @param category - The category
     *  @return Collection - A collection of threads under the given category
     */
    public Collection findByCategory( final int category )
                                                    throws SQLException,
			CategoryNotFoundException;

    /**
     *  Get the top-level threads under the given category from start index
     *
     *  @param category - The category
     *  @param startIndex - The start index for retrieveing the records
     *  @param length - The number of records to be tretieved
     *  @return Collection - A collection of threads under the given category
     */
    public Collection findByCategory( final int category,
                                      final int startIndex,
                                      final int length ) throws SQLException,
                                                                CategoryNotFoundException;

    /**
     *  Get a thread given a unique id
     *
     * @return PersistentThread - The corresponding thread
     */
    public PersistentThread findByUID( final long id ) throws SQLException,ThreadNotFoundException;


    /**
     *  Get all the children threads given a id of a parent threa
     *
     *  @return Collection - A collection of children threads
     *
     */
    public Collection findByParnetID( final long parentID ) throws ThreadNotFoundException, SQLException;

    /**
     *  Get all the children threads given a id of a parent threa
     *
     *  @param parentID - The id of a parnt thread
     *  @param startIndex - The number of row that we start to get the children threads
     *  @param endIndex - The number of row we end geting the children threads
     *  @return Collection - A collection of children threads
     *
     */
    public Collection findByParnetID( final long parentID, final int startIndex, final int endIndex ) throws SQLException;

     /**
     *  Get the top-level threads count under the given category from start index
     *
     *  @param category - The category
     *  @return int - The top-level threads count under a category
     */
    public int findCountByCategory( final int category ) throws SQLException;

	/**
	 * update Thread from DB
	 */
	public void updateThread( final PersistentThread thread ) throws SQLException, ThreadNotFoundException;
	/**
	 * Update the click count
	 */
	public void updateClick(long id) throws SQLException;

     /**
      *  Get a list of Threads owned by a given auther
      * @param userId - the author's name
      * return Collection - a list of Threads
      */
     public Collection findByUserId(String userId) throws SQLException;

	/**
     *  Remove a new thread from the DB
     */
    public void removeThread( final long threadID ) throws SQLException;

    /**
     * Find all threads posted later than <code>time</code>
     * (compare timestamp field of threads table in db with time)
     * 
     * @param time  time in milliseconds
     *              use System.currentTimeMillis() to get current time
     *              if time==0, return all threads
     * @return      all threads found
     * @exception   exception when querying db
     *
     */
    public Collection findThreadsPostedLaterThan( long time ) throws SQLException;

}//EOI