[INLONG-10995][SDK] Transform SQL support Chr function

inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/ChrFunction.java

@@ -0,0 +1,59 @@
+/*
+ * 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.Function;
+
+import java.math.BigDecimal;
+
+/***
+ * ChrFunction
+ * description: chr(numeric)--returns the ASCII character having the binary equivalent to integer
+**/
+@TransformFunction(names = {"chr"})
+public class ChrFunction implements ValueParser {
+
+    private ValueParser numberParser;
+    private final int chrSum = 256;
+
+    public ChrFunction(Function expr) {
+        numberParser = OperatorTools.buildParser(expr.getParameters().getExpressions().get(0));
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        if (numberParser == null) {
+            return null;
+        }
+        Object numberObj = numberParser.parse(sourceData, rowIndex, context);
+        if (numberObj == null) {
+            return null;
+        }
+        BigDecimal numberValue = OperatorTools.parseBigDecimal(numberObj);
+
+        BigDecimal temp = numberValue.remainder(new BigDecimal(chrSum));
+        BigDecimal res = (temp.compareTo(BigDecimal.ZERO) >= 0) ? temp : temp.add(new BigDecimal(chrSum));
+
+        return String.valueOf((char) res.intValue());
+    }
+}

inlong-sdk/transform-sdk/src/test/java/org/apache/inlong/sdk/transform/process/TestChrFunctionProcessor.java

@@ -0,0 +1,85 @@
+/*
+ * 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;
+
+import org.apache.inlong.sdk.transform.decode.SourceDecoderFactory;
+import org.apache.inlong.sdk.transform.encode.SinkEncoderFactory;
+import org.apache.inlong.sdk.transform.pojo.CsvSourceInfo;
+import org.apache.inlong.sdk.transform.pojo.FieldInfo;
+import org.apache.inlong.sdk.transform.pojo.KvSinkInfo;
+import org.apache.inlong.sdk.transform.pojo.TransformConfig;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * TestChrFunctionProcessor
+ * description: test chr functions in transform processor
+ */
+public class TestChrFunctionProcessor {
+
+    private static final List<FieldInfo> srcFields = new ArrayList<>();
+    private static final List<FieldInfo> dstFields = new ArrayList<>();
+    private static final CsvSourceInfo csvSource;
+    private static final KvSinkInfo kvSink;
+
+    static {
+        for (int i = 1; i < 4; i++) {
+            FieldInfo field = new FieldInfo();
+            field.setName("numeric" + i);
+            srcFields.add(field);
+        }
+        FieldInfo field = new FieldInfo();
+        field.setName("result");
+        dstFields.add(field);
+        csvSource = new CsvSourceInfo("UTF-8", '|', '\\', srcFields);
+        kvSink = new KvSinkInfo("UTF-8", dstFields);
+    }
+
+    @Test
+    public void testChrFunction() throws Exception {
+        String transformSql1 = "select chr(numeric1) from source";
+        TransformConfig config1 = new TransformConfig(transformSql1);
+        TransformProcessor<String, String> processor1 = TransformProcessor
+                .create(config1, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        // case1: chr(97)
+        List<String> output1 = processor1.transform("97|5|6|8|1|3", new HashMap<>());
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=a");
+
+        // case2: translate("hello word!", "el", "EL")
+        List<String> output2 = processor1.transform("353|5|6|8|1|3", new HashMap<>());
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=a");
+
+        String transformSql2 = "select chr(numericx) from source";
+        TransformConfig config2 = new TransformConfig(transformSql2);
+        TransformProcessor<String, String> processor2 = TransformProcessor
+                .create(config2, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        // case3: chr(null)
+        List<String> output3 = processor2.transform("|5|6|8|1|9", new HashMap<>());
+        Assert.assertEquals(1, output3.size());
+        Assert.assertEquals(output3.get(0), "result=null");
+    }
+}