StringTrimmedResultSet.java Source code

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Here is the source code for StringTrimmedResultSet.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.sql.ResultSet;

/**
 * Wraps a <code>ResultSet</code> to trim strings returned by the
 * <code>getString()</code> and <code>getObject()</code> methods.
 * 
 * <p>
 * Usage Example:
 * This example shows how to decorate ResultSets so processing continues as 
 * normal but all Strings are trimmed before being returned from the 
 * <code>ResultSet</code>.
 * </p>
 * 
 * <pre>
 * ResultSet rs = // somehow get a ResultSet;
 * 
 * // Substitute wrapped ResultSet with additional behavior for real ResultSet
 * rs = StringTrimmedResultSet.wrap(rs);
 * 
 * // Pass wrapped ResultSet to processor
 * List list = new BasicRowProcessor().toBeanList(rs);
 * </pre>
 */
public class StringTrimmedResultSet implements InvocationHandler {

    /**
     * The wrapped result. 
     */
    private final ResultSet rs;

    /**
     * Constructs a new instance of <code>StringTrimmedResultSet</code>
     * to wrap the specified <code>ResultSet</code>.
     * @param rs ResultSet to wrap
     */
    public StringTrimmedResultSet(ResultSet rs) {
        super();
        this.rs = rs;
    }

    /**
     * Intercept calls to the <code>getString()</code> and 
     * <code>getObject()</code> methods and trim any Strings before they're
     * returned.
     * 
     * @throws Throwable
     * @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

        Object result = method.invoke(this.rs, args);

        if (method.getName().equals("getObject") || method.getName().equals("getString")) {

            if (result instanceof String) {
                result = ((String) result).trim();
            }
        }

        return result;
    }

}