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 *  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
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package org.apache.cayenne.access.jdbc;

import java.io.IOException;
import java.io.Writer;

import org.apache.velocity.context.InternalContextAdapter;

/**
 * A custom Velocity directive to create a PreparedStatement parameter text for "<>?".
 * If null value is encountered, generated text will look like "IS NOT NULL". Usage in
 * Velocity template is "WHERE SOME_COLUMN #bindNotEqual($xyz)".
 * 
 * @since 1.1
 * @author Andrei Adamchik
 */
public class BindNotEqualDirective extends BindDirective {

    public String getName() {
        return "bindNotEqual";
    }

    protected void render(
            InternalContextAdapter context,
            Writer writer,
            ParameterBinding binding) throws IOException {

        if (binding.getValue() != null) {
            bind(context, binding);
            writer.write("<> ?");
        }
        else {
            writer.write("IS NOT NULL");
        }
    }
}
