/**
 * 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.
 */

package com.huawei.streaming.udfs;

import java.util.Map;

/**
 * 求取字符串长度
 * 
 */
@UDFAnnotation(name = "strlength")
public class StringLength extends UDF
{
    /**
     * 注释内容
     */
    private static final long serialVersionUID = 6337310251870706210L;
    
    /**
     * <默认构造函数>
     * @param config udf函数中需要的参数，这些参数要在cql中通过全局变量进行设置。
     */
    public StringLength(Map<String, String> config)
    {
        super(config);
    }
    
    /**
     * 计算函数
     * @param str 待计算字符串
     * @return 计算出来的字符串长度
     */
    public int evaluate(String str)
    {
        return str == null ? 0 : str.length();
    }
    
}
