/**
* Read metadata about a table from the database.
*
* @param table The RDBMS table.
* @return A map of information about the columns. The key is the name of the column, a String;
* the value is a ColumnInfo object.
* @exception SQLException If there is a problem retrieving information from the RDBMS.
*/
private static Map<String, ColumnInfo> retrieveColumnInfo(String table) throws SQLException {
Connection connection = null;
ResultSet pkcolumns = null;
ResultSet columns = null;
try {
String schema = ConfigurationManager.getProperty("db.schema");
if (StringUtils.isBlank(schema)) {
schema = null;
}
String catalog = null;
int dotIndex = table.indexOf('.');
if (dotIndex > 0) {
catalog = table.substring(0, dotIndex);
table = table.substring(dotIndex + 1, table.length());
log.warn("catalog: " + catalog);
log.warn("table: " + table);
}
connection = getConnection();
DatabaseMetaData metadata = connection.getMetaData();
Map<String, ColumnInfo> results = new HashMap<String, ColumnInfo>();
int max = metadata.getMaxTableNameLength();
String tname = ((max > 0) && (table.length() >= max)) ? table.substring(0, max - 1) : table;
pkcolumns = metadata.getPrimaryKeys(catalog, schema, tname);
Set<String> pks = new HashSet<String>();
while (pkcolumns.next()) {
pks.add(pkcolumns.getString(4));
}
columns = metadata.getColumns(catalog, schema, tname, null);
while (columns.next()) {
String column = columns.getString(4);
ColumnInfo cinfo = new ColumnInfo();
cinfo.setName(column);
cinfo.setType((int) columns.getShort(5));
if (pks.contains(column)) {
cinfo.setIsPrimaryKey(true);
}
results.put(column, cinfo);
}
return Collections.unmodifiableMap(results);
} finally {
if (pkcolumns != null) {
try {
pkcolumns.close();
} catch (SQLException sqle) {
}
}
if (columns != null) {
try {
columns.close();
} catch (SQLException sqle) {
}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException sqle) {
}
}
}
}
