package hirondelle.web4j.database;
import hirondelle.web4j.BuildImpl;
import hirondelle.web4j.model.ConvertParam;
import hirondelle.web4j.model.DateTime;
import hirondelle.web4j.model.Decimal;
import hirondelle.web4j.model.Id;
import hirondelle.web4j.security.SafeText;
import hirondelle.web4j.util.Util;
import java.math.BigDecimal;
import java.sql.Clob;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Types;
import java.util.Locale;
import java.util.TimeZone;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
Default implementation of {@link ConvertColumn}, suitable for most applications.
<P>This class converts non-<tt>null</tt> items using :
<table border='1' cellspacing='0' cellpadding='3'>
<tr><th>Target Class</th><th>Use</th></tr>
<tr><td><tt> SafeText </tt></td><td><tt> ResultSet.getString(), or ResultSet.getClob() </tt></td></tr>
<tr><td><tt> String (if allowed) </tt></td><td><tt> ResultSet.getString(), or ResultSet.getClob() </tt></td></tr>
<tr><td><tt> Integer </tt></td><td><tt>ResultSet.getInt()</tt></td></tr>
<tr><td><tt> Long </tt></td><td><tt> ResultSet.getLong() </tt></td></tr>
<tr><td><tt> Boolean </tt></td><td><tt> ResultSet.getBoolean() </tt></td></tr>
<tr><td><tt> BigDecimal </tt></td><td><tt> ResultSet.getBigDecimal() </tt></td></tr>
<tr><td><tt> Decimal</tt></td><td><tt> ResultSet.getBigDecimal()</tt></td></tr>
<tr><td><tt> Id </tt></td><td><tt> ResultSet.getString(), new Id(String)</tt></td></tr>
<tr><td><tt> DateTime </tt></td><td><tt> ResultSet.getString()</tt>, pass to {@link DateTime#DateTime(String)}</td></tr>
<tr><td><tt> Date </tt></td><td><tt> ResultSet.getTimestamp()</tt>, possibly with hint provided in <tt>web.xml</tt></td></tr>
<tr><td><tt> Locale </tt></td><td><tt> ResultSet.getString(), {@link hirondelle.web4j.util.Util#buildLocale(String)}</tt></td></tr>
<tr><td><tt> TimeZone </tt></td><td><tt> ResultSet.getString(), {@link hirondelle.web4j.util.Util#buildTimeZone(String)}</tt></td></tr>
</table>
<P>This implementation supports the same building block classes defined by another
default implementation : {@link hirondelle.web4j.model.ConvertParamImpl#isSupported(Class)}.
See that class for important information on the conditional support of <tt>String</tt>.
*/
public class ConvertColumnImpl implements ConvertColumn {
/**
Defines policies for converting a column of a <tt>ResultSet</tt> into a possibly-null
<tt>Object</tt>.
@param aRow of a <tt>ResultSet</tt>
@param aColumnIdx particular column of aRow
@param aSupportedTargetType is a class supported by the configured implementation of
{@link ConvertParam#isSupported(Class)}.
*/
public <T> T convert(ResultSet aRow, int aColumnIdx, Class<T> aSupportedTargetType) throws SQLException {
if( ! fConvertParam.isSupported(aSupportedTargetType) ){
throw new IllegalArgumentException("Unsupported Target Type : " + Util.quote(aSupportedTargetType));
}
Object result = null;
if (aSupportedTargetType == SafeText.class){
result = convertToSafeText(aRow, aColumnIdx);
}
else if (aSupportedTargetType == String.class) {
result = convertToString(aRow, aColumnIdx);
}
else if (aSupportedTargetType == Integer.class || aSupportedTargetType == int.class){
int value = aRow.getInt(aColumnIdx);
result = aRow.wasNull() ? null : new Integer(value);
}
else if (aSupportedTargetType == Boolean.class || aSupportedTargetType == boolean.class){
boolean value = aRow.getBoolean(aColumnIdx);
result = aRow.wasNull() ? null : Boolean.valueOf(value);
}
else if (aSupportedTargetType == BigDecimal.class){
result = aRow.getBigDecimal(aColumnIdx);
}
else if (aSupportedTargetType == java.util.Date.class){
result = getDate(aRow, aColumnIdx);
}
else if (aSupportedTargetType == DateTime.class){
result = getDateTime(aRow, aColumnIdx);
}
else if (aSupportedTargetType == Long.class || aSupportedTargetType == long.class){
long value = aRow.getLong(aColumnIdx);
result = aRow.wasNull() ? null : new Long(value);
}
else if (aSupportedTargetType == Id.class){
String value = aRow.getString(aColumnIdx);
result = aRow.wasNull() ? null : new Id(value);
}
else if (aSupportedTargetType == Locale.class){
String value = aRow.getString(aColumnIdx);
result = value == null ? null : Util.buildLocale(value);
}
else if (aSupportedTargetType == TimeZone.class){
String value = aRow.getString(aColumnIdx);
result = value == null ? null : Util.buildTimeZone(value);
}
else if (aSupportedTargetType == Decimal.class){
BigDecimal value = aRow.getBigDecimal(aColumnIdx);
result = value == null ? null : new Decimal(value);
}
else {
throw new AssertionError(
"Unsupported type cannot be translated to an object:" + aSupportedTargetType
);
}
fLogger.finest(
"Successfully converted ResultSet column idx " + Util.quote(aColumnIdx) +
" into a " + aSupportedTargetType.getName()
);
return (T)result; //this cast is unavoidable, and safe.
}
// PRIVATE
private final ConvertParam fConvertParam = BuildImpl.forConvertParam();
private static final Logger fLogger = Util.getLogger(ConvertColumnImpl.class);
private SafeText convertToSafeText(ResultSet aRow, int aColumnIdx) throws SQLException {
String result = convertToString(aRow, aColumnIdx);
return result == null ? null : new SafeText(result);
}
private String convertToString(ResultSet aRow, int aColumnIdx) throws SQLException {
String result = null;
if ( isClob(aRow, aColumnIdx) ) {
result = convertClobToString(aRow, aColumnIdx);
}
else {
result = aRow.getString(aColumnIdx);
}
return aRow.wasNull() ? null : result;
}
private static boolean isClob(ResultSet aRow, int aColumnIdx) throws SQLException {
ResultSetMetaData metaData = aRow.getMetaData();
boolean result = metaData.getColumnType(aColumnIdx) == Types.CLOB;
return result;
}
private static String convertClobToString(ResultSet aRow, int aColumnIdx) throws SQLException {
String result = null;
Clob clob = aRow.getClob(aColumnIdx);
if (clob != null){
int length = new Long(clob.length()).intValue();
result = clob.getSubString(1, length);
}
return result;
}
private java.util.Date getDate(ResultSet aRow, int aColumnIdx) throws SQLException {
java.util.Date result = null;
String DEFAULT_DB = "";
if ( DbConfig.hasTimeZoneHint() ){
result = aRow.getTimestamp(aColumnIdx, DbConfig.getTimeZoneHint());
}
else {
result = aRow.getTimestamp(aColumnIdx);
}
return result;
}
private DateTime getDateTime(ResultSet aRow, int aColumnIdx) throws SQLException {
//the ctor takes any String; if malformed, the DateTime will blow up later, when you call most other methods
String rawDateTime = aRow.getString(aColumnIdx);
if(fLogger.getLevel() == Level.FINEST){
fLogger.finest("DateTime column, raw value from database is: " + Util.quote(rawDateTime) +
". SQL date-time formatting functions can be used to render the format compatible with the hirondelle.web4.model.DateTime class, if needed."
);
}
return rawDateTime == null ? null : new DateTime(rawDateTime);
}
}