track.java

此程序都是企业级 的数据库开发程序 全面揭示了JAVA对数据库的操作

package statements;

import java.sql.*;
import java.util.*;
import connections.ConnectionFactory;

public class Track {
  //track data
  int recordingId;
  String recordingTitle;
  int trackNumber;
  String trackTitle;
  int artistId;
  String artistName;
  int styleId;
  String styleName;
  String sampleFilespec;

  //JDBC variables
  PreparedStatement preparedStmt;
  ResultSet resultSet;
  Vector results;

  //CRUD flags
  boolean create;
  boolean retrieve;
  boolean update;
  boolean delete;
    
  static String sqlSelect = "SELECT " + 
    "recordings.recordingid, " +
    "recordings.recordingtitle, " +
    "tracks.tracknumber, " +
    "tracks.tracktitle, " +
    "tracks.artistid, " +
    "artistsandperformers.artistname, " +
    "tracks.styleid, " +
    "audiostyles.audiostyledescription, " +
    "tracks.samplefilespec ";
  static String sqlFrom = 
    "FROM tracks, recordings, artistsandperformers, audiostyles ";
  static String sqlWhere = "WHERE ";
  static String sqlWhereCont =
    "LIKE ? AND recordings.recordingid = tracks.recordingid AND " +
    "artistsandperformers.artistid = tracks.artistid AND " +
    "audiostyles.audiostyleid = tracks.styleid";
  static String sqlInsert = "INSERT INTO TRACKS " +
    "(recordingid, tracknumber, tracktitle, " +
    "artistid, styleid, samplefilespec) VALUES (?, ?, ?, ?, ?, ?)";

  //constructor
  public Track() {}

  // Returns the SQL INSERT statement used by this class for creating
  // an entry in the database
  public static String getCreateSql() {
    return sqlInsert;
  }

   //Prepare the class for creating (inserting) a row in the
   //database. The PreparedStatement should be created using the SQL
   //string obtained by calling the method getCreateSql() in this
   //class.
  public void setCreateStatement(PreparedStatement ps) {
    preparedStmt = ps;
    create = (ps != null ? true : false);
    retrieve = false; 
    update = false;
    delete = false;
  }

  //methods to return differen SQL strings for searching
  public static String getFindTrackTitleSql() 
  {
    return sqlSelect + sqlFrom + sqlWhere +
      "tracks.tracktitle " + sqlWhereCont;
  }
  
  public static String getFindRecordTitleSql() 
  {
    return sqlSelect + sqlFrom + sqlWhere +
      "recordings.recordingtitle " + sqlWhereCont;
  }
  
  public static String getFindArtistSql() 
  {
    return sqlSelect + sqlFrom + sqlWhere +
      "artistsandperformers.artistname " + sqlWhereCont;
  }
  
   //Prepare the class to query for rows in the database. The
   //PreparedStatement should be created using the SQL string obtained
   //by calling one of the getFindXXXSql() methods in this class.
  public void setQueryStatement(PreparedStatement ps) {
    preparedStmt = ps;
    create = false; 
    retrieve = (ps != null ? true : false);
    update = false;
    delete = false;
  }

  //execute the PreparedStatement
  private boolean executeSql() throws SQLException {
    if (create || update || delete) {
      int result = preparedStmt.executeUpdate();
      return (result == 1);
    } else if (retrieve) {
      resultSet = preparedStmt.executeQuery();
      results = new Vector();
      if (resultSet.next()) {
	Track track = new Track();
	track.populate(resultSet);
	results.add(track);
	return true;
      }
      return false;
    } else {
      throw new SQLException("No PreparedStatement has been set.");
    }     
  }

  //Find tracks that match a TrackTitle search string
  public Vector findByTrackTitle(String trackTitle) 
    throws SQLException
  {
    preparedStmt.setString(1, "%" + trackTitle + "%");
    if (executeSql()) {
      parseResultSet();
    }
    return results;
  }

  //Find tracks that match a Recording Title search string
  public Vector findByRecordingTitle(String recordingTitle)
    throws SQLException
  {
    preparedStmt.setString(1, "%" + recordingTitle + "%");
    if (executeSql()) {
      parseResultSet();
    }
    return results;
  }
  
  //Find tracks that match an Artist name search string
  public Vector findByArtistName(String artistName)
    throws SQLException
  {
    preparedStmt.setString(1, "%" + artistName + "%");
    if (executeSql()) {
      parseResultSet();
    }
    return results;
  }

  //Read each row in the ResultSet and create a Track instance from
  //the row
  private void parseResultSet() throws SQLException
  {
    try {
      while (resultSet.next()) {
	Track track = new Track();
	track.populate(resultSet);
	results.add(track);
      }
    } finally {
      ConnectionFactory.close(resultSet);
    }
  }

  //initialize the datamembers of this class using data from the
  //current row of the ResultSet
  public void populate(ResultSet rset) throws SQLException
  {
    setRecordingId(rset.getInt("RECORDINGID"));
    setRecordingTitle(rset.getString("RECORDINGTITLE"));
    setTrackNumber(rset.getInt("TRACKNUMBER"));
    setTrackTitle(rset.getString("TRACKTITLE"));
    setArtistId(rset.getInt("ARTISTID"));
    setArtistName(rset.getString("ARTISTNAME"));
    setStyleId(rset.getInt("STYLEID"));
    setStyleName(rset.getString("AUDIOSTYLEDESCRIPTION"));
    setSampleFilespec(rset.getString("SAMPLEFILESPEC"));
  }

  //Setters and Getters for the member variables
  
  public int getRecordingId() { return recordingId; }
  public void setRecordingId(int v) throws SQLException { 
    recordingId = v; 
  }

  public int getTrackNumber() { return trackNumber; }
  public void setTrackNumber(int v) throws SQLException { 
    trackNumber = v;
  }

  public String getTrackTitle() { return trackTitle; }
  public void setTrackTitle(String v) throws SQLException { 
    trackTitle = v;
  }

  public int getArtistId() { return artistId; }
  public void setArtistId(int v) throws SQLException { 
    artistId = v;
  }

  public int getStyleId() { return styleId; }
  public void setStyleId(int v) throws SQLException {
    styleId = v;
  }

  public String getSampleFilespec() { return sampleFilespec; }
  public void setSampleFilespec(String v) throws SQLException {
    sampleFilespec = v; 
  }

  public String getRecordingTitle() { return recordingTitle; }
  public void setRecordingTitle(String v) {
    recordingTitle = v;
  }
  
  public String getStyleName() { return styleName; }
  public void setStyleName(String v) {
    styleName = v;
  }
  
  public String getArtistName() { return artistName; }
  public void setArtistName(String v) {
    artistName = v;
  }    
}