[INLONG-10841][SDK] Transform SQL supports toBase64 function

inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/ToBase64Function.java

@@ -0,0 +1,48 @@
+/*
+ * 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.nio.charset.StandardCharsets;
+import java.util.Base64;
+
+/**
+ * ToBase64Function
+ * description: to_base64(string1)--returns the base64-encoded result from string1
+ */
+public class ToBase64Function implements ValueParser {
+
+    private final ValueParser stringParser;
+
+    public ToBase64Function(Function expr) {
+        stringParser = OperatorTools.buildParser(expr.getParameters().getExpressions().get(0));
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        Object stringObj = stringParser.parse(sourceData, rowIndex, context);
+        String string = OperatorTools.parseString(stringObj);
+        return Base64.getEncoder().encodeToString(string.getBytes(StandardCharsets.UTF_8));
+    }
+}

inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/operator/OperatorTools.java

@@ -41,6 +41,7 @@
 import org.apache.inlong.sdk.transform.process.function.SqrtFunction;
 import org.apache.inlong.sdk.transform.process.function.SubstringFunction;
 import org.apache.inlong.sdk.transform.process.function.TimestampExtractFunction;
+import org.apache.inlong.sdk.transform.process.function.ToBase64Function;
 import org.apache.inlong.sdk.transform.process.function.ToDateFunction;
 import org.apache.inlong.sdk.transform.process.function.ToTimestampFunction;
 import org.apache.inlong.sdk.transform.process.function.TrimFunction;
@@ -138,6 +139,7 @@ public class OperatorTools {
         functionMap.put("from_unixtime", FromUnixTimeFunction::new);
         functionMap.put("unix_timestamp", UnixTimestampFunction::new);
         functionMap.put("to_timestamp", ToTimestampFunction::new);
+        functionMap.put("to_base64", ToBase64Function::new);
     }
 
     public static ExpressionOperator buildOperator(Expression expr) {

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

@@ -184,4 +184,20 @@ public void testTrimFunction() throws Exception {
         Assert.assertEquals(output3.get(0), "result=in long");
     }
 
+    @Test
+    public void testToBase64Function() throws Exception {
+        String transformSql = "select to_base64(string1) from source";
+        TransformConfig config = new TransformConfig(transformSql);
+        TransformProcessor<String, String> processor1 = TransformProcessor
+                .create(config, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        // to_base64('app-fun')
+        List<String> output1 = processor1.transform("app-fun", new HashMap<>());
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=YXBwLWZ1bg==");
+        // to_base64('hello world')
+        List<String> output2 = processor1.transform("hello world", new HashMap<>());
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=aGVsbG8gd29ybGQ=");
+    }
 }