yfsn666 commented on code in PR #10928: URL: https://github.com/apache/inlong/pull/10928#discussion_r1734153110
########## inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/LpadFunction.java: ########## @@ -0,0 +1,78 @@ +/* + * 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 org.apache.inlong.sdk.transform.process.function; + +import org.apache.inlong.sdk.transform.decode.SourceData; +import org.apache.inlong.sdk.transform.process.Context; +import org.apache.inlong.sdk.transform.process.operator.OperatorTools; +import org.apache.inlong.sdk.transform.process.parser.ValueParser; + +import net.sf.jsqlparser.expression.Expression; +import net.sf.jsqlparser.expression.Function; + +import java.util.List; + +/** + * LpadFunction + * description: Lpad(s1,len,s2) Fill string s2 at the beginning of string s1 to make the string length len + * - return null if any of the three parameters is null or len is less than 0 + * - return "" if s2 is "" + * - return the substring of s1 with subscripts in the range of [0, len) if len is less than the length of s1 + * - return the filled string + */ +public class LpadFunction implements ValueParser { + + private final ValueParser leftStringParser; + private final ValueParser lengthParser; + private final ValueParser rightStringParser; + + public LpadFunction(Function expr) { + List<Expression> expressions = expr.getParameters().getExpressions(); + leftStringParser = OperatorTools.buildParser(expressions.get(0)); + lengthParser = OperatorTools.buildParser(expressions.get(1)); + rightStringParser = OperatorTools.buildParser(expressions.get(2)); + } + + @Override + public Object parse(SourceData sourceData, int rowIndex, Context context) { + Object leftStringObj = leftStringParser.parse(sourceData, rowIndex, context); + Object lengthObj = lengthParser.parse(sourceData, rowIndex, context); + Object rightStringObj = rightStringParser.parse(sourceData, rowIndex, context); + if (leftStringObj == null || lengthObj == null || rightStringObj == null) { + return null; + } + int len = Integer.parseInt(OperatorTools.parseString(lengthObj)); + if (len < 0) { + return null; + } + String rightStr = OperatorTools.parseString(rightStringObj); + if (rightStr.isEmpty()) { + return ""; + } Review Comment: Why this function return "" if s2 is "", is there any official documentation? For example, lpad("hi", 1, "") returns "h" may be more appropriate? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@inlong.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
