1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.dbutils;
18
19 import java.lang.reflect.InvocationHandler;
20 import java.lang.reflect.Proxy;
21 import java.sql.CallableStatement;
22 import java.sql.Connection;
23 import java.sql.Driver;
24 import java.sql.PreparedStatement;
25 import java.sql.ResultSet;
26 import java.sql.ResultSetMetaData;
27 import java.sql.Statement;
28
29 /**
30 * Creates proxy implementations of JDBC interfaces. This avoids
31 * incompatibilities between the JDBC 2 and JDBC 3 interfaces. This class is
32 * thread safe.
33 *
34 * @see java.lang.reflect.Proxy
35 * @see java.lang.reflect.InvocationHandler
36 */
37 public class ProxyFactory {
38
39 /**
40 * The Singleton instance of this class.
41 */
42 private static final ProxyFactory instance = new ProxyFactory();
43
44 /**
45 * Returns the Singleton instance of this class.
46 *
47 * @return singleton instance
48 */
49 public static ProxyFactory instance() {
50 return instance;
51 }
52
53 /**
54 * Protected constructor for ProxyFactory subclasses to use.
55 */
56 protected ProxyFactory() {
57 super();
58 }
59
60 /**
61 * Convenience method to generate a single-interface proxy using the handler's classloader
62 *
63 * @param <T> The type of object to proxy
64 * @param type The type of object to proxy
65 * @param handler The handler that intercepts/overrides method calls.
66 * @return proxied object
67 */
68 public <T> T newProxyInstance(Class<T> type, InvocationHandler handler) {
69 return type.cast(Proxy.newProxyInstance(handler.getClass().getClassLoader(), new Class<?>[] {type}, handler));
70 }
71
72 /**
73 * Creates a new proxy <code>CallableStatement</code> object.
74 * @param handler The handler that intercepts/overrides method calls.
75 * @return proxied CallableStatement
76 */
77 public CallableStatement createCallableStatement(InvocationHandler handler) {
78 return newProxyInstance(CallableStatement.class, handler);
79 }
80
81 /**
82 * Creates a new proxy <code>Connection</code> object.
83 * @param handler The handler that intercepts/overrides method calls.
84 * @return proxied Connection
85 */
86 public Connection createConnection(InvocationHandler handler) {
87 return newProxyInstance(Connection.class, handler);
88 }
89
90 /**
91 * Creates a new proxy <code>Driver</code> object.
92 * @param handler The handler that intercepts/overrides method calls.
93 * @return proxied Driver
94 */
95 public Driver createDriver(InvocationHandler handler) {
96 return newProxyInstance(Driver.class, handler);
97 }
98
99 /**
100 * Creates a new proxy <code>PreparedStatement</code> object.
101 * @param handler The handler that intercepts/overrides method calls.
102 * @return proxied PreparedStatement
103 */
104 public PreparedStatement createPreparedStatement(InvocationHandler handler) {
105 return newProxyInstance(PreparedStatement.class, handler);
106 }
107
108 /**
109 * Creates a new proxy <code>ResultSet</code> object.
110 * @param handler The handler that intercepts/overrides method calls.
111 * @return proxied ResultSet
112 */
113 public ResultSet createResultSet(InvocationHandler handler) {
114 return newProxyInstance(ResultSet.class, handler);
115 }
116
117 /**
118 * Creates a new proxy <code>ResultSetMetaData</code> object.
119 * @param handler The handler that intercepts/overrides method calls.
120 * @return proxied ResultSetMetaData
121 */
122 public ResultSetMetaData createResultSetMetaData(InvocationHandler handler) {
123 return newProxyInstance(ResultSetMetaData.class, handler);
124 }
125
126 /**
127 * Creates a new proxy <code>Statement</code> object.
128 * @param handler The handler that intercepts/overrides method calls.
129 * @return proxied Statement
130 */
131 public Statement createStatement(InvocationHandler handler) {
132 return newProxyInstance(Statement.class, handler);
133 }
134
135 }