song.ejb

J2EE的一个开发实例

package music.ejb.db;

import java.util.Collection;
import javax.ejb.*;
import weblogic.ejb.*;

import music.shared.*;

/**
 * @ejbgen:entity default-transaction="Required" prim-key-class="java.lang.Integer"
 *   ejb-name = "Song"
 *   data-source-name="jdbc/MusicDataSource"
 *   table-name = "song"
 *   abstract-schema-name = "Song"
 *
 * @ejbgen:jndi-name
 *   local="ejb/Song"
 *
 * @ejbgen:file-generation local-class = "True" local-class-name = "SongLocal" local-home = "True" local-home-name="SongLocalHome" remote-class = "False" remote-home = "False"  remote-home-name = "SongRemoteHome" remote-class-name = "SongRemote" value-class = "False" value-class-name = "SongValue" pk-class = "True"
 *
 * @ejbgen:automatic-key-generation name="id" type="SQLServer2000"
 * @ejbgen:relation role-name="Songs-have-Album" fk-column="Album_Id" cmr-field="album" target-ejb="Album" multiplicity="Many" name="Album-Song"
 * @ejbgen:finder ejb-ql="SELECT OBJECT(o) from Song as o where lower(o.title) like concat('%', concat(?1, '%'))" generate-on="Local" signature="Collection findByTitle(java.lang.String title)"
 */
abstract public class Song
  extends GenericEntityBean
  implements EntityBean
{

    /**
     * @ejbgen:cmp-field primkey-field="true" column="Id"
     * @ejbgen:local-method
     */
    public abstract Integer getId();

    /**
     */
    public abstract void setId(Integer arg);

    /**
     * @ejbgen:cmp-field column="Title"
     * @ejbgen:local-method
     */
    public abstract String getTitle();

    /**
     * @ejbgen:local-method
     */

    public abstract void setTitle(String arg);

    /**
     * @ejbgen:cmp-field column="Type"
     * @ejbgen:local-method
     */
    public abstract int getType();

    /**
     * @ejbgen:local-method
     */
    public abstract void setType(int arg);

    /**
     * @ejbgen:cmp-field column="Url"
     * @ejbgen:local-method
     */
    public abstract String getUrl();

    /**
     * @ejbgen:local-method
     */
    public abstract void setUrl(String arg);

    /**
     * @ejbgen:cmp-field column="Lyric"
     * @ejbgen:local-method
     */
    public abstract String getLyric();

    /**
     * @ejbgen:local-method
     */
    public abstract void setLyric(String arg);

    /**
     * @ejbgen:cmp-field column="DownloadTimes"
     * @ejbgen:local-method
     */
    public abstract int getDownloadTimes();

    /**
     */
    public abstract void setDownloadTimes(int arg);

    /**
     * @ejbgen:cmp-field column="Rating"
     * @ejbgen:local-method
     */
    public abstract double getRating();

    /**
     */
    public abstract void setRating(double arg);

    /**
     * @ejbgen:cmp-field column="RatingTimes"
     * @ejbgen:local-method
     */
    public abstract int getRatingTimes();

    /**
     */
    public abstract void setRatingTimes(int arg);

    /**
     * @ejbgen:cmr-field
     * @ejbgen:local-method
     */
    public abstract AlbumLocal getAlbum();

    /**
     * @ejbgen:local-method
     */
    public abstract void setAlbum(AlbumLocal arg);

    /**
     * @ejbgen:local-method
     */
    public SongVO copy()
    {
        return new SongVO(getId().intValue(), getTitle(), getType(),
            getUrl(), getLyric(), rate(), getDownloadTimes()
        );
    }

    /**
     * return the rating: 1-5
     * @ejbgen:local-method
     */
    public int rate()
    {
        double r = getRating();
        if(r<1.8)
            return 1;
        if(r<2.6)
            return 2;
        if(r<3.6)
            return 3;
        if(r<4.2)
            return 4;
        return 5;
    }

    /**
     * mark must between 1-5
     * @ejbgen:local-method
     */
    public int rate(int mark)
    {
        // the mark must between 1-5:
        if (mark<1) mark = 1;
        if (mark>5) mark = 5;
        // calculate the new mark:
        int times = getRatingTimes();
        double total = getRating() * times + mark;
        times ++;
        double newMark = total / times;
        if(newMark<1.0) newMark = 1.0;
        if(newMark>5.0) newMark = 5.0;
        // ok, update the database:
        setRatingTimes(times);
        setRating(newMark);
        return rate();
    }

    public java.lang.Integer ejbCreate(java.lang.String Title, int Type, java.lang.String Url, java.lang.String Lyric)
    {
        setTitle(Title);
        setType(Type);
        setUrl(Url);
        setLyric(Lyric);

        setDownloadTimes(0);
        setRating(3.0);
        setRatingTimes(0);

        return null; // FIXME return PK value 
    }

    public void ejbPostCreate(java.lang.String Title, int Type, java.lang.String Url, java.lang.String Lyric)
    {
    }

    /**
     * @ejbgen:local-method
     */
    public Collection fullPath()
    {
        Collection c = getAlbum().fullPath();
        c.add(copy());
        return c;
    }

    /**
     * @ejbgen:local-method
     */
    public boolean hasLyric()
    {
        return (getLyric()!=null);
    }

    /**
     * @ejbgen:local-method
     */
    public boolean hasUrl()
    {
        return (getUrl()!=null);
    }

}