databaseloader.java

矩阵的QR分解算法

	    vals[i - 1] = index.doubleValue();
	  }
	  break;
	case DatabaseConnection.BOOL:
	  boolean boo = rs.getBoolean(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (boo ? 1.0 : 0.0);
	  }
	  break;
	case DatabaseConnection.DOUBLE:
	  //	  BigDecimal bd = rs.getBigDecimal(i, 4); 
	  double dd = rs.getDouble(i);
	  // Use the column precision instead of 4?
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    //	    newInst.setValue(i - 1, bd.doubleValue());
	    vals[i - 1] =  dd;
	  }
	  break;
	case DatabaseConnection.BYTE:
	  byte by = rs.getByte(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (double)by;
	  }
	  break;
	case DatabaseConnection.SHORT:
	  short sh = rs.getByte(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (double)sh;
	  }
	  break;
	case DatabaseConnection.INTEGER:
	  int in = rs.getInt(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (double)in;
	  }
	  break;
	case DatabaseConnection.LONG:
	  long lo = rs.getLong(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (double)lo;
	  }
	  break;
	case DatabaseConnection.FLOAT:
	  float fl = rs.getFloat(i);
	  if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
	    vals[i - 1] = (double)fl;
	  }
	  break;
	case DatabaseConnection.DATE:
          Date date = rs.getDate(i);
          if (rs.wasNull()) {
	    vals[i - 1] = Instance.missingValue();
	  } else {
            // TODO: Do a value check here.
            vals[i - 1] = (double)date.getTime();
          }
          break;
	default:
	  vals[i - 1] = Instance.missingValue();
	}
      }
       Instance inst = new Instance(1.0, vals);
       //get rid of m_idColumn
       if(m_DataBaseConnection.getUpperCase())
              m_idColumn = m_idColumn.toUpperCase();
       if(m_structure.attribute(0).name().equals(m_idColumn)){
            inst.deleteAttributeAt(0);
            m_oldStructure.add(inst);
            inst = m_oldStructure.instance(0);
            m_oldStructure.delete(0);
       }
       else{
        //instances is added to and deleted from the structure to get the true nominal values instead of the index of the values.
        m_structure.add(inst);
        inst = m_structure.instance(0);
        m_structure.delete(0);
       }
       return inst;
       
  }

  /**
   * Read the data set incrementally---get the next instance in the data 
   * set or returns null if there are no
   * more instances to get. If the structure hasn't yet been 
   * determined by a call to getStructure then method does so before
   * returning the next instance in the data set.
   *
   * @param structure the dataset header information, will get updated in 
   * case of string or relational attributes
   * @return the next instance in the data set as an Instance object or null
   * if there are no more instances to be read
   * @throws IOException if there is an error during parsing
   */
  public Instance getNextInstance(Instances structure) throws IOException {

    m_structure = structure;
      
    if (m_DataBaseConnection == null) 
      throw new IOException("No source database has been specified"); 
    if (getRetrieval() == BATCH) {
      throw new IOException("Cannot mix getting Instances in both incremental and batch modes");
    }
    //pseudoInremental: Load all instances into main memory in batch mode and give them incrementally to user
    if(m_pseudoIncremental){
        setRetrieval(INCREMENTAL);
        if(m_datasetPseudoInc.numInstances() > 0){
            Instance current = m_datasetPseudoInc.instance(0);
            m_datasetPseudoInc.delete(0);
            return current;
        }
        else{
            resetStructure();
            return null;
        }
    }
    //real incremental mode. At the moment(version 1.0) only for MySQL and HSQLDB (Postgres not tested, should work)
    setRetrieval(INCREMENTAL);
    try{
        if(!m_DataBaseConnection.isConnected())
            connectToDatabase();
        //if no key columns specified by user, try to detect automatically
        if(m_firstTime && m_orderBy.size() == 0){
            if(!checkForKey())
                throw new Exception("A unique order cannot be detected automatically.\nYou have to use SELECT * in your query to enable this feature.\nMaybe JDBC driver is not able to detect key.\nDefine primary key in your database or use -P option (command line) or enter key columns in the GUI.");
        }
        if(m_firstTime){
            m_firstTime = false;
            m_rowCount = getRowCount();
        }
        //as long as not all rows has been loaded
        if(m_counter < m_rowCount){
            if (m_DataBaseConnection.execute(limitQuery(m_query,m_counter,m_choice)) == false) {
                throw new Exception("Tuple could not be retrieved.");
            }
            m_counter++;
            ResultSet rs = m_DataBaseConnection.getResultSet();
            rs.next();
            Instance current = readInstance(rs);
            rs.close();
            return current;
        }
        else{
            m_DataBaseConnection.disconnectFromDatabase();
            resetStructure();
            return null;
        }
    }catch(Exception ex) {
        printException(ex);
    }
    return null;
  }
  
  
  
  /** 
   * Gets the setting
   * 
   * @return the current setting
   */  
  public String[] getOptions() {
      
    Vector options = new Vector();

    if ( (getUrl() != null) && (getUrl().length() != 0) ) {
      options.add("-url");
      options.add(getUrl());
    }
    
    if ( (getUser() != null) && (getUser().length() != 0) ) {
      options.add("-user");
      options.add(getUser());
    }
    
    if ( (getPassword() != null) && (getPassword().length() != 0) ) {
      options.add("-password");
      options.add(getPassword());
    }

    options.add("-Q"); 
    options.add(getQuery());
    
    StringBuffer text = new StringBuffer();
    for (int i = 0; i < m_orderBy.size(); i++) {
      if (i > 0)
        text.append(", ");
      text.append((String) m_orderBy.elementAt(i));
    }
    options.add("-P"); 
    options.add(text.toString());
    
    if (m_inc)
      options.add("-I");
    
    return (String[]) options.toArray(new String[options.size()]);
  }
  
  /** 
   * Lists the available options
   * 
   * @return an enumeration of the available options
   */  
  public java.util.Enumeration listOptions() {
      
     FastVector newVector = new FastVector();

     newVector.addElement(new Option(
           "\tThe JDBC URL to connect to.\n"
           + "\t(default: from DatabaseUtils.props file)",
           "url", 1, "-url <JDBC URL>"));
     
     newVector.addElement(new Option(
           "\tThe user to connect with to the database.\n"
           + "\t(default: none)",
           "user", 1, "-user <name>"));
     
     newVector.addElement(new Option(
           "\tThe password to connect with to the database.\n"
           + "\t(default: none)",
           "password", 1, "-password <password>"));
     
     newVector.addElement(new Option(
	 "\tSQL query of the form\n"
	 + "\t\tSELECT <list of columns>|* FROM <table> [WHERE]\n"
	 + "\tto execute.\n"
         + "\t(default: Select * From Results0)",
	 "Q",1,"-Q <query>"));
     
     newVector.addElement(new Option(
	 "\tList of column names uniquely defining a DB row\n"
	 + "\t(separated by ', ').\n"
         + "\tUsed for incremental loading.\n"
	 + "\tIf not specified, the key will be determined automatically,\n"
	 + "\tif possible with the used JDBC driver.\n"
	 + "\tThe auto ID column created by the DatabaseSaver won't be loaded.",
	 "P",1,"-P <list of column names>"));

     newVector.addElement(new Option(
	 "\tSets incremental loading", 
	 "I", 0, "-I"));
     
     return  newVector.elements();
  }
  
  /** 
   * Sets the options.
   *
   <!-- options-start -->
   * Valid options are: <p/>
   * 
   * <pre> -url &lt;JDBC URL&gt;
   *  The JDBC URL to connect to.
   *  (default: from DatabaseUtils.props file)</pre>
   * 
   * <pre> -user &lt;name&gt;
   *  The user to connect with to the database.
   *  (default: none)</pre>
   * 
   * <pre> -password &lt;password&gt;
   *  The password to connect with to the database.
   *  (default: none)</pre>
   * 
   * <pre> -Q &lt;query&gt;
   *  SQL query of the form
   *   SELECT &lt;list of columns&gt;|* FROM &lt;table&gt; [WHERE]
   *  to execute.
   *  (default: Select * From Results0)</pre>
   * 
   * <pre> -P &lt;list of column names&gt;
   *  List of column names uniquely defining a DB row
   *  (separated by ', ').
   *  Used for incremental loading.
   *  If not specified, the key will be determined automatically,
   *  if possible with the used JDBC driver.
   *  The auto ID column created by the DatabaseSaver won't be loaded.</pre>
   * 
   * <pre> -I
   *  Sets incremental loading</pre>
   * 
   <!-- options-end -->
   *
   * @param options the options
   * @throws Exception if options cannot be set
   */  
  public void setOptions(String[] options) throws Exception {
      
    String optionString, keyString, tmpStr;
    
    optionString = Utils.getOption('Q', options);
    
    keyString = Utils.getOption('P', options);
    
    reset();
    
    tmpStr = Utils.getOption("url", options);
    if (tmpStr.length() != 0)
      setUrl(tmpStr);

    tmpStr = Utils.getOption("user", options);
    if (tmpStr.length() != 0)
      setUser(tmpStr);
    
    tmpStr = Utils.getOption("password", options);
    if (tmpStr.length() != 0)
      setPassword(tmpStr);
    
    if (optionString.length() != 0)
      setQuery(optionString);
    
    m_orderBy.removeAllElements();
    
    m_inc = Utils.getFlag('I', options);
    
    if(m_inc){
        StringTokenizer st = new StringTokenizer(keyString, ",");
        while (st.hasMoreTokens()) {
            String column = st.nextToken();
            column = column.replaceAll(" ","");
            m_orderBy.addElement(column);
        }
    }
  }
  
  /**Prints an exception
   * @param ex the exception to print
   */  
  private void printException(Exception ex){
  
      System.out.println("\n--- Exception caught ---\n");
	while (ex != null) {
		System.out.println("Message:   "
                                   + ex.getMessage ());
                if(ex instanceof SQLException){
                    System.out.println("SQLState:  "
                                   + ((SQLException)ex).getSQLState ());
                    System.out.println("ErrorCode: "
                                   + ((SQLException)ex).getErrorCode ());
                    ex = ((SQLException)ex).getNextException();
                }
                else
                    ex = null;
		System.out.println("");
	}
      
      
  }

  /** Main method.
   * @param options the options
   */
  public static void main(String [] options) {
    
      DatabaseLoader atf;
      try {
	atf = new DatabaseLoader();
        atf.setOptions(options);
        atf.setSource(atf.getUrl(), atf.getUser(), atf.getPassword());
        if(!atf.m_inc)
            System.out.println(atf.getDataSet());
        else{
            Instances structure = atf.getStructure();
            System.out.println(structure);
            Instance temp;
            do {
            temp = atf.getNextInstance(structure);
            if (temp != null) {
                System.out.println(temp);
            }
            } while (temp != null);
        }
      } catch (Exception e) {
	e.printStackTrace();
        System.out.println("\n"+e.getMessage());
      }
  }
}