01: /*
02:
03: Derby - Class org.apache.derby.impl.jdbc.EmbedResultSetMetaData40
04:
05: Licensed to the Apache Software Foundation (ASF) under one or more
06: contributor license agreements. See the NOTICE file distributed with
07: this work for additional information regarding copyright ownership.
08: The ASF licenses this file to you under the Apache License, Version 2.0
09: (the "License"); you may not use this file except in compliance with
10: the License. You may obtain a copy of the License at
11:
12: http://www.apache.org/licenses/LICENSE-2.0
13:
14: Unless required by applicable law or agreed to in writing, software
15: distributed under the License is distributed on an "AS IS" BASIS,
16: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17: See the License for the specific language governing permissions and
18: limitations under the License.
19:
20: */
21: package org.apache.derby.impl.jdbc;
22:
23: import java.sql.SQLException;
24:
25: import org.apache.derby.iapi.reference.SQLState;
26: import org.apache.derby.iapi.sql.ResultColumnDescriptor;
27:
28: public class EmbedResultSetMetaData40 extends EmbedResultSetMetaData {
29:
30: public EmbedResultSetMetaData40(ResultColumnDescriptor[] columnInfo) {
31: super (columnInfo);
32: }
33:
34: /**
35: * Returns false unless <code>interfaces</code> is implemented
36: *
37: * @param interfaces a Class defining an interface.
38: * @return true if this implements the interface or
39: * directly or indirectly wraps an object
40: * that does.
41: * @throws java.sql.SQLException if an error occurs while determining
42: * whether this is a wrapper for an object
43: * with the given interface.
44: */
45: public boolean isWrapperFor(Class<?> interfaces)
46: throws SQLException {
47: return interfaces.isInstance(this );
48: }
49:
50: /**
51: * Returns <code>this</code> if this class implements the interface
52: *
53: * @param interfaces a Class defining an interface
54: * @return an object that implements the interface
55: * @throws java.sql.SQLExption if no object if found that implements the
56: * interface
57: */
58: public <T> T unwrap(java.lang.Class<T> interfaces)
59: throws SQLException {
60: //Derby does not implement non-standard methods on
61: //JDBC objects
62: //hence return this if this class implements the interface
63: //or throw an SQLException
64: try {
65: return interfaces.cast(this );
66: } catch (ClassCastException cce) {
67: throw Util.generateCsSQLException(
68: SQLState.UNABLE_TO_UNWRAP, interfaces);
69: }
70: }
71: }
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