jfinal对象封装Record原理

 

 

 

/*DbPro.class*/

public transient Record findFirst(String sql, Object paras[]{
List result = find(sql, paras);
return result.size() <= 0 ? null : (Record)result.get(0);
}


public transient List find(String sql, Object paras[])
{
Connection conn = null;
List list;
try
{
conn = config.getConnection();
list = find(config, conn, sql, paras);
}
catch(Exception e)
{
throw new ActiveRecordException(e);
}
config.close(conn);
return list;
Exception exception;
exception;
config.close(conn);
throw exception;
}


transient List find(Config config, Connection conn, String sql, Object paras[])
throws SQLException
{
PreparedStatement pst = conn.prepareStatement(sql);
config.dialect.fillStatement(pst, paras);
ResultSet rs = pst.executeQuery();
List result = RecordBuilder.build(config, rs);   //返回List<Record>
DbKit.closeQuietly(rs, pst);
return result;
}


/*RecordBuilder.class
*把一条记录对象封装Record对象
*/
public static final List build(Config config, ResultSet rs)
throws SQLException
{
List result = new ArrayList();
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
String labelNames[] = new String[columnCount + 1];
int types[] = new int[columnCount + 1];
buildLabelNamesAndTypes(rsmd, labelNames, types);
Record record;
for(; rs.next(); result.add(record))
{
record = new Record();
record.setColumnsMap(config.containerFactory.getColumnsMap());
Map columns = record.getColumns();
for(int i = 1; i <= columnCount; i++)
{
Object value;
if(types[i] < 2004)
value = rs.getObject(i);
else
if(types[i] == 2005)
value = ModelBuilder.handleClob(rs.getClob(i));
else
if(types[i] == 2011)
value = ModelBuilder.handleClob(rs.getNClob(i));
else
if(types[i] == 2004)
value = ModelBuilder.handleBlob(rs.getBlob(i));
else
value = rs.getObject(i);
columns.put(labelNames[i], value);
}

}

return result;
}