weka.gui.sql.ResultSetHelper Maven / Gradle / Ivy
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see ", we can't use absolute(int)
// and getRow()???
try {
if ((m_RowCount == 0) && (m_ResultSet.first())) {
m_RowCount = 1;
while (m_ResultSet.next()) {
m_RowCount++;
if (m_ResultSet.getRow() == m_MaxRows) {
break;
}
}
;
}
} catch (Exception e) {
// ignore it
}
}
m_Initialized = true;
} catch (Exception ex) {
// ignore it
}
}
/**
* the underlying resultset.
*
* @return the resultset
*/
public ResultSet getResultSet() {
return m_ResultSet;
}
/**
* returns the number of columns in the resultset.
*
* @return the number of columns
*/
public int getColumnCount() {
initialize();
return m_ColumnCount;
}
/**
* returns the number of rows in the resultset. If -1 then the number of rows
* couldn't be determined, i.e., the cursors aren't scrollable.
*
* @return the number of rows, -1 if it wasn't possible to determine
*/
public int getRowCount() {
initialize();
return m_RowCount;
}
/**
* returns an array with the names of the columns in the resultset.
*
* @return the column names
*/
public String[] getColumnNames() {
initialize();
return m_ColumnNames;
}
/**
* returns an array that indicates whether a column is numeric or nor.
*
* @return the numeric columns
*/
public boolean[] getNumericColumns() {
initialize();
return m_NumericColumns;
}
/**
* returns the classes for the columns.
*
* @return the column classes
*/
public Class[] getColumnClasses() {
initialize();
return m_ColumnClasses;
}
/**
* whether a limit on the rows to retrieve was set.
*
* @return true if there's a limit
*/
public boolean hasMaxRows() {
return (m_MaxRows > 0);
}
/**
* the maximum number of rows to retrieve, less than 1 means unlimited.
*
* @return the maximum number of rows
*/
public int getMaxRows() {
return m_MaxRows;
}
/**
* returns an 2-dimensional array with the content of the resultset, the first
* dimension is the row, the second the column (i.e., getCells()[y][x]). Note:
* the data is not cached! It is always retrieved anew.
*
* @return the data
*/
public Object[][] getCells() {
int i;
int n;
Vector result;
Object[] row;
int rowCount;
boolean proceed;
initialize();
result = new Vector();
try {
// do know the number of rows?
rowCount = getRowCount();
if (rowCount == -1) {
rowCount = getMaxRows();
proceed = m_ResultSet.next();
} else {
proceed = m_ResultSet.first();
}
if (proceed) {
i = 0;
while (true) {
row = new Object[getColumnCount()];
result.add(row);
for (n = 0; n < getColumnCount(); n++) {
try {
// to get around byte arrays when using getObject(int)
if (getColumnClasses()[n] == String.class) {
row[n] = m_ResultSet.getString(n + 1);
} else {
row[n] = m_ResultSet.getObject(n + 1);
}
} catch (Exception e) {
row[n] = null;
}
}
// get next row, if possible
if (i == rowCount - 1) {
break;
} else {
// no more rows -> exit
if (!m_ResultSet.next()) {
break;
}
}
i++;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return result.toArray(new Object[result.size()][getColumnCount()]);
}
/**
* Returns the class associated with a SQL type.
*
* @param type the SQL type
* @return the Java class corresponding with the type
*/
public static Class typeToClass(int type) {
Class result;
switch (type) {
case Types.BIGINT:
result = Long.class;
break;
case Types.BINARY:
result = String.class;
break;
case Types.BIT:
result = Boolean.class;
break;
case Types.CHAR:
result = Character.class;
break;
case Types.DATE:
result = java.sql.Date.class;
break;
case Types.DECIMAL:
result = Double.class;
break;
case Types.DOUBLE:
result = Double.class;
break;
case Types.FLOAT:
result = Float.class;
break;
case Types.INTEGER:
result = Integer.class;
break;
case Types.LONGVARBINARY:
result = String.class;
break;
case Types.LONGVARCHAR:
result = String.class;
break;
case Types.NULL:
result = String.class;
break;
case Types.NUMERIC:
result = Double.class;
break;
case Types.OTHER:
result = String.class;
break;
case Types.REAL:
result = Double.class;
break;
case Types.SMALLINT:
result = Short.class;
break;
case Types.TIME:
result = java.sql.Time.class;
break;
case Types.TIMESTAMP:
result = java.sql.Timestamp.class;
break;
case Types.TINYINT:
result = Short.class;
break;
case Types.VARBINARY:
result = String.class;
break;
case Types.VARCHAR:
result = String.class;
break;
default:
result = null;
}
return result;
}
/**
* returns whether the SQL type is numeric (and therefore the justification
* should be right).
*
* @param type the SQL type
* @return whether the given type is numeric
*/
public static boolean typeIsNumeric(int type) {
boolean result;
switch (type) {
case Types.BIGINT:
result = true;
break;
case Types.BINARY:
result = false;
break;
case Types.BIT:
result = false;
break;
case Types.CHAR:
result = false;
break;
case Types.DATE:
result = false;
break;
case Types.DECIMAL:
result = true;
break;
case Types.DOUBLE:
result = true;
break;
case Types.FLOAT:
result = true;
break;
case Types.INTEGER:
result = true;
break;
case Types.LONGVARBINARY:
result = false;
break;
case Types.LONGVARCHAR:
result = false;
break;
case Types.NULL:
result = false;
break;
case Types.NUMERIC:
result = true;
break;
case Types.OTHER:
result = false;
break;
case Types.REAL:
result = true;
break;
case Types.SMALLINT:
result = true;
break;
case Types.TIME:
result = false;
break;
case Types.TIMESTAMP:
result = true;
break;
case Types.TINYINT:
result = true;
break;
case Types.VARBINARY:
result = false;
break;
case Types.VARCHAR:
result = false;
break;
default:
result = false;
}
return result;
}
}
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