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.wrappers;
018:
019: import java.lang.reflect.InvocationHandler;
020: import java.lang.reflect.Method;
021: import java.sql.ResultSet;
022:
023: import org.apache.commons.dbutils.ProxyFactory;
024:
025: /**
026: * Wraps a <code>ResultSet</code> to trim strings returned by the
027: * <code>getString()</code> and <code>getObject()</code> methods.
028: *
029: * <p>
030: * Usage Example:
031: * This example shows how to decorate ResultSets so processing continues as
032: * normal but all Strings are trimmed before being returned from the
033: * <code>ResultSet</code>.
034: * </p>
035: *
036: * <pre>
037: * ResultSet rs = // somehow get a ResultSet;
038: *
039: * // Substitute wrapped ResultSet with additional behavior for real ResultSet
040: * rs = StringTrimmedResultSet.wrap(rs);
041: *
042: * // Pass wrapped ResultSet to processor
043: * List list = new BasicRowProcessor().toBeanList(rs);
044: * </pre>
045: */
046: public class StringTrimmedResultSet implements InvocationHandler {
047:
048: /**
049: * The factory to create proxies with.
050: */
051: private static final ProxyFactory factory = ProxyFactory.instance();
052:
053: /**
054: * Wraps the <code>ResultSet</code> in an instance of this class. This is
055: * equivalent to:
056: * <pre>
057: * ProxyFactory.instance().createResultSet(new StringTrimmedResultSet(rs));
058: * </pre>
059: *
060: * @param rs The <code>ResultSet</code> to wrap.
061: * @return wrapped ResultSet
062: */
063: public static ResultSet wrap(ResultSet rs) {
064: return factory.createResultSet(new StringTrimmedResultSet(rs));
065: }
066:
067: /**
068: * The wrapped result.
069: */
070: private final ResultSet rs;
071:
072: /**
073: * Constructs a new instance of <code>StringTrimmedResultSet</code>
074: * to wrap the specified <code>ResultSet</code>.
075: * @param rs ResultSet to wrap
076: */
077: public StringTrimmedResultSet(ResultSet rs) {
078: super ();
079: this .rs = rs;
080: }
081:
082: /**
083: * Intercept calls to the <code>getString()</code> and
084: * <code>getObject()</code> methods and trim any Strings before they're
085: * returned.
086: *
087: * @throws Throwable
088: * @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])
089: */
090: public Object invoke(Object proxy, Method method, Object[] args)
091: throws Throwable {
092:
093: Object result = method.invoke(this .rs, args);
094:
095: if (method.getName().equals("getObject")
096: || method.getName().equals("getString")) {
097:
098: if (result instanceof String) {
099: result = ((String) result).trim();
100: }
101: }
102:
103: return result;
104: }
105:
106: }
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