Row object
* maintains an array of current column values and an array of original
* column values, and it provides methods for getting and setting the
* value of a column. It also keeps track of which columns have
* changed and whether the change was a delete, insert, or update.
*
* Note that column numbers for rowsets start at 1,
* whereas the first element of an array or bitset is 0.
* The argument for the method getColumnUpdated refers to
* the column number in the rowset (the first column is 1);
* the argument for setColumnUpdated refers to the index
* into the rowset's internal bitset (the first bit is 0).
*/
public class Row extends BaseRow implements Serializable, Cloneable {
/**
* An array containing the current column values for this Row
* object.
* @serial
*/
private Object[] currentVals;
/**
* A BitSet object containing a flag for each column in
* this Row object, with each flag indicating whether or
* not the value in the column has been changed.
* @serial
*/
private BitSet colsChanged;
/**
* A boolean indicating whether or not this Row
* object has been deleted. true indicates that it has
* been deleted; false indicates that it has not.
* @serial
*/
private boolean deleted;
/**
* A boolean indicating whether or not this Row
* object has been updated. true indicates that it has
* been updated; false indicates that it has not.
* @serial
*/
private boolean updated;
/**
* A boolean indicating whether or not this Row
* object has been inserted. true indicates that it has
* been inserted; false indicates that it has not.
* @serial
*/
private boolean inserted;
/**
* The number of columns in this Row object.
* @serial
*/
private int numCols;
/**
* Creates a new Row object with the given number of columns.
* The newly-created row includes an array of original values,
* an array for storing its current values, and a BitSet
* object for keeping track of which column values have been changed.
*/
public Row(int numCols) {
origVals = new Object[numCols];
currentVals = new Object[numCols];
colsChanged = new BitSet(numCols);
this.numCols = numCols;
}
/**
* Creates a new Row object with the given number of columns
* and with its array of original values initialized to the given array.
* The new Row object also has an array for storing its
* current values and a BitSet object for keeping track
* of which column values have been changed.
*/
public Row(int numCols, Object[] vals) {
origVals = new Object[numCols];
for (int i=0; i < numCols; i++) {
origVals[i] = vals[i];
}
currentVals = new Object[numCols];
colsChanged = new BitSet(numCols);
this.numCols = numCols;
}
/**
*
* This method is called internally by the CachedRowSet.populate
* methods.
*
* @param idx the number of the column in this Row object
* that is to be set; the index of the first column is
* 1
* @param val the new value to be set
*/
public void initColumnObject(int idx, Object val) {
origVals[idx - 1] = val;
}
/**
*
* This method is called internally by the CachedRowSet.updateXXX
* methods.
*
* @param idx the number of the column in this Row object
* that is to be set; the index of the first column is
* 1
* @param val the new value to be set
*/
public void setColumnObject(int idx, Object val) {
currentVals[idx - 1] = val;
setColUpdated(idx - 1);
}
/**
* Retrieves the column value stored in the designated column of this
* Row object.
*
* @param columnIndex the index of the column value to be retrieved;
* the index of the first column is 1
* @return an Object in the Java programming language that
* represents the value stored in the designated column
* @throws SQLException if there is a database access error
*/
public Object getColumnObject(int columnIndex) throws SQLException {
if (getColUpdated(columnIndex - 1)) {
return(currentVals[columnIndex - 1]); // maps to array!!
} else {
return(origVals[columnIndex - 1]); // maps to array!!
}
}
/**
* Indicates whether the designated column of this Row object
* has been changed.
* @param idx the index into the BitSet object maintained by
* this Row object to keep track of which column
* values have been modified; the index of the first bit is
* 0
* @return true if the designated column value has been changed;
* false otherwise
*
*/
public boolean getColUpdated(int idx) {
return colsChanged.get(idx);
}
/**
* Sets this Row object's deleted field
* to true.
*
* @see #getDeleted
*/
public void setDeleted() { // %%% was public
deleted = true;
}
/**
* Retrieves the value of this Row object's deleted field,
* which will be true if one or more of its columns has been
* deleted.
* @return true if a column value has been deleted; false
* otherwise
*
* @see #setDeleted
*/
public boolean getDeleted() {
return(deleted);
}
/**
* Sets the deleted field for this Row object to
* false.
*/
public void clearDeleted() {
deleted = false;
}
/**
* Sets the value of this Row object's inserted field
* to true.
*
* @see #getInserted
*/
public void setInserted() {
inserted = true;
}
/**
* Retrieves the value of this Row object's inserted field,
* which will be true if this row has been inserted.
* @return true if this row has been inserted; false
* otherwise
*
* @see #setInserted
*/
public boolean getInserted() {
return(inserted);
}
/**
* Sets the inserted field for this Row object to
* false.
*/
public void clearInserted() { // %%% was public
inserted = false;
}
/**
* Retrieves the value of this Row object's
* updated field.
* @return true if this Row object has been
* updated; false if it has not
*
* @see #setUpdated
*/
public boolean getUpdated() {
return(updated);
}
/**
* Sets the updated field for this Row object to
* true if one or more of its column values has been changed.
*
* @see #getUpdated
*/
public void setUpdated() {
// only mark something as updated if one or
// more of the columns has been changed.
for (int i = 0; i < numCols; i++) {
if (getColUpdated(i) == true) {
updated = true;
return;
}
}
}
/**
* Sets the bit at the given index into this Row object's internal
* BitSet object, indicating that the corresponding column value
* (column idx + 1) has been changed.
*
* @param idx the index into the BitSet object maintained by
* this Row object; the first bit is at index
* 0
*
*/
private void setColUpdated(int idx) {
colsChanged.set(idx);
}
/**
* Sets the updated field for this Row object to
* false, sets all the column values in this Row
* object's internal array of current values to null, and clears
* all of the bits in the BitSet object maintained by this
* Row object.
*/
public void clearUpdated() {
updated = false;
for (int i = 0; i < numCols; i++) {
currentVals[i] = null;
colsChanged.clear(i);
}
}
/**
* Sets the column values in this Row object's internal
* array of original values with the values in its internal array of
* current values, sets all the values in this Row
* object's internal array of current values to null,
* clears all the bits in this Row object's internal bitset,
* and sets its updated field to false.
*
* This method is called internally by the CachedRowSet
* method makeRowOriginal.
*/
public void moveCurrentToOrig() {
for (int i = 0; i < numCols; i++) {
if (getColUpdated(i) == true) {
origVals[i] = currentVals[i];
currentVals[i] = null;
colsChanged.clear(i);
}
}
updated = false;
}
/**
* Returns the row on which the cursor is positioned.
*
* @return the Row object on which the CachedRowSet
* implementation objects's cursor is positioned
*/
public BaseRow getCurrentRow() {
return null;
}
}