001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.dbutils; 018 019 import java.lang.reflect.InvocationHandler; 020 import java.lang.reflect.Proxy; 021 import java.sql.CallableStatement; 022 import java.sql.Connection; 023 import java.sql.Driver; 024 import java.sql.PreparedStatement; 025 import java.sql.ResultSet; 026 import java.sql.ResultSetMetaData; 027 import java.sql.Statement; 028 029 /** 030 * Creates proxy implementations of JDBC interfaces. This avoids 031 * incompatibilities between the JDBC 2 and JDBC 3 interfaces. This class is 032 * thread safe. 033 * 034 * @see java.lang.reflect.Proxy 035 * @see java.lang.reflect.InvocationHandler 036 */ 037 public class ProxyFactory { 038 039 /** 040 * The Singleton instance of this class. 041 */ 042 private static final ProxyFactory instance = new ProxyFactory(); 043 044 /** 045 * Returns the Singleton instance of this class. 046 * 047 * @return singleton instance 048 */ 049 public static ProxyFactory instance() { 050 return instance; 051 } 052 053 /** 054 * Protected constructor for ProxyFactory subclasses to use. 055 */ 056 protected ProxyFactory() { 057 super(); 058 } 059 060 /** Convenience method to generate a single-interface proxy using the handler's classloader 061 * 062 * @param <T> The type of object to proxy 063 * @param type The type of object to proxy 064 * @param handler The handler that intercepts/overrides method calls. 065 * @return proxied object 066 */ 067 public <T> T newProxyInstance(Class<T> type, InvocationHandler handler) { 068 return type.cast(Proxy.newProxyInstance(handler.getClass().getClassLoader(), new Class<?>[] {type}, handler)); 069 } 070 071 /** 072 * Creates a new proxy <code>CallableStatement</code> object. 073 * @param handler The handler that intercepts/overrides method calls. 074 * @return proxied CallableStatement 075 */ 076 public CallableStatement createCallableStatement(InvocationHandler handler) { 077 return newProxyInstance(CallableStatement.class, handler); 078 } 079 080 /** 081 * Creates a new proxy <code>Connection</code> object. 082 * @param handler The handler that intercepts/overrides method calls. 083 * @return proxied Connection 084 */ 085 public Connection createConnection(InvocationHandler handler) { 086 return newProxyInstance(Connection.class, handler); 087 } 088 089 /** 090 * Creates a new proxy <code>Driver</code> object. 091 * @param handler The handler that intercepts/overrides method calls. 092 * @return proxied Driver 093 */ 094 public Driver createDriver(InvocationHandler handler) { 095 return newProxyInstance(Driver.class, handler); 096 } 097 098 /** 099 * Creates a new proxy <code>PreparedStatement</code> object. 100 * @param handler The handler that intercepts/overrides method calls. 101 * @return proxied PreparedStatement 102 */ 103 public PreparedStatement createPreparedStatement(InvocationHandler handler) { 104 return newProxyInstance(PreparedStatement.class, handler); 105 } 106 107 /** 108 * Creates a new proxy <code>ResultSet</code> object. 109 * @param handler The handler that intercepts/overrides method calls. 110 * @return proxied ResultSet 111 */ 112 public ResultSet createResultSet(InvocationHandler handler) { 113 return newProxyInstance(ResultSet.class, handler); 114 } 115 116 /** 117 * Creates a new proxy <code>ResultSetMetaData</code> object. 118 * @param handler The handler that intercepts/overrides method calls. 119 * @return proxied ResultSetMetaData 120 */ 121 public ResultSetMetaData createResultSetMetaData(InvocationHandler handler) { 122 return newProxyInstance(ResultSetMetaData.class, handler); 123 } 124 125 /** 126 * Creates a new proxy <code>Statement</code> object. 127 * @param handler The handler that intercepts/overrides method calls. 128 * @return proxied Statement 129 */ 130 public Statement createStatement(InvocationHandler handler) { 131 return newProxyInstance(Statement.class, handler); 132 } 133 134 }