Merge pull request #18479 from AndreiBranza/BAEL-8051-serialize-enum-value-in-avro

[BAEL-8051-serialize-enum-value-in-avro] - article code

Author: davidmartinezbarua

apache-libraries-3/src/test/java/com/baeldung/apache/avro/SerializeEnumValueInAvroUnitTest.java

@@ -0,0 +1,179 @@
+package com.baeldung.apache.avro;
+
+import org.apache.avro.Schema;
+import org.apache.avro.SchemaBuilder;
+import org.apache.avro.file.DataFileReader;
+import org.apache.avro.file.DataFileWriter;
+import org.apache.avro.generic.GenericData;
+import org.apache.avro.generic.GenericDatumReader;
+import org.apache.avro.generic.GenericDatumWriter;
+import org.apache.avro.generic.GenericRecord;
+import org.apache.avro.io.DatumReader;
+import org.apache.avro.io.DatumWriter;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class SerializeEnumValueInAvroUnitTest {
+
+    @TempDir
+    Path tempDir;
+
+    private Schema colorEnum;
+    private Schema recordSchema;
+    private Schema unionSchema;
+    private Schema recordWithUnionSchema;
+
+    @BeforeEach
+    void setUp() {
+        // Create enum schema
+        colorEnum = SchemaBuilder.enumeration("Color")
+                .namespace("com.baeldung.apache.avro")
+                .symbols("UNKNOWN", "GREEN", "RED", "BLUE");
+
+        // Create record schema with enum field
+        recordSchema = SchemaBuilder.record("ColorRecord")
+                .namespace("com.baeldung.apache.avro")
+                .fields()
+                .name("color")
+                .type(colorEnum)
+                .noDefault()
+                .endRecord();
+
+        // Create union schema with enum and null
+        unionSchema = SchemaBuilder.unionOf()
+                .type(colorEnum)
+                .and()
+                .nullType()
+                .endUnion();
+
+        // Create record schema with union field
+        recordWithUnionSchema = SchemaBuilder.record("ColorRecordWithUnion")
+                .namespace("com.baeldung.apache.avro")
+                .fields()
+                .name("color")
+                .type(unionSchema)
+                .noDefault()
+                .endRecord();
+    }
+
+    @Test
+    void whenSerializingEnum_thenSuccess() throws IOException {
+        File file = tempDir.resolve("color.avro").toFile();
+
+        // Create record with enum value
+        GenericRecord record = new GenericData.Record(recordSchema);
+        GenericData.EnumSymbol colorSymbol = new GenericData.EnumSymbol(colorEnum, "RED");
+        record.put("color", colorSymbol);
+
+        // Write to file
+        DatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<>(recordSchema);
+        try (DataFileWriter<GenericRecord> dataFileWriter = new DataFileWriter<>(datumWriter)) {
+            dataFileWriter.create(recordSchema, file);
+            dataFileWriter.append(record);
+        }
+
+        // Read from file
+        DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(recordSchema);
+        try (DataFileReader<GenericRecord> dataFileReader = new DataFileReader<>(file, datumReader)) {
+            GenericRecord result = dataFileReader.next();
+            assertEquals("RED", result.get("color").toString());
+        }
+    }
+
+    @Test
+    void whenSerializingEnumInUnion_thenSuccess() throws IOException {
+        File file = tempDir.resolve("colorUnion.avro").toFile();
+
+        // Create record with enum in union
+        GenericRecord record = new GenericData.Record(recordWithUnionSchema);
+        GenericData.EnumSymbol colorSymbol = new GenericData.EnumSymbol(colorEnum, "GREEN");
+        record.put("color", colorSymbol);
+
+        // Write to file
+        DatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<>(recordWithUnionSchema);
+        try (DataFileWriter<GenericRecord> dataFileWriter = new DataFileWriter<>(datumWriter)) {
+            dataFileWriter.create(recordWithUnionSchema, file);
+            dataFileWriter.append(record);
+        }
+
+        // Read from file
+        DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(recordWithUnionSchema);
+        try (DataFileReader<GenericRecord> dataFileReader = new DataFileReader<>(file, datumReader)) {
+            GenericRecord result = dataFileReader.next();
+            assertEquals("GREEN", result.get("color").toString());
+        }
+    }
+
+    @Test
+    void whenSerializingNullInUnion_thenSuccess() throws IOException {
+        File file = tempDir.resolve("colorNull.avro").toFile();
+
+        // Create record with null in union
+        GenericRecord record = new GenericData.Record(recordWithUnionSchema);
+        record.put("color", null);
+
+        // Write to file
+        DatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<>(recordWithUnionSchema);
+        assertDoesNotThrow(() -> {
+            try (DataFileWriter<GenericRecord> dataFileWriter = new DataFileWriter<>(datumWriter)) {
+                dataFileWriter.create(recordWithUnionSchema, file);
+                dataFileWriter.append(record);
+            }
+        });
+    }
+
+    @Test
+    void whenSchemaEvolution_thenDefaultValueUsed() throws IOException {
+        // Create schema with new enum value and default at schema level
+        String evolvedSchemaJson = "{\"type\":\"record\"," +
+                "\"name\":\"ColorRecord\"," +
+                "\"namespace\":\"com.baeldung.apache.avro\"," +
+                "\"fields\":[{\"name\":\"color\"," +
+                "\"type\":{\"type\":\"enum\"," +
+                "\"name\":\"Color\"," +
+                "\"symbols\":[\"UNKNOWN\",\"GREEN\",\"RED\",\"BLUE\",\"YELLOW\"]," +
+                "\"default\":\"UNKNOWN\"}}]}";
+
+        Schema evolvedRecordSchema = new Schema.Parser().parse(evolvedSchemaJson);
+        Schema evolvedEnum = evolvedRecordSchema.getField("color").schema();
+
+        File file = tempDir.resolve("colorEvolved.avro").toFile();
+
+        // Create record with new enum value
+        GenericRecord record = new GenericData.Record(evolvedRecordSchema);
+        GenericData.EnumSymbol colorSymbol = new GenericData.EnumSymbol(evolvedEnum, "YELLOW");
+        record.put("color", colorSymbol);
+
+        // Write with evolved schema
+        DatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<>(evolvedRecordSchema);
+        try (DataFileWriter<GenericRecord> dataFileWriter = new DataFileWriter<>(datumWriter)) {
+            dataFileWriter.create(evolvedRecordSchema, file);
+            dataFileWriter.append(record);
+        }
+
+        // Create old schema without YELLOW but WITH default
+        String originalSchemaJson = "{\"type\":\"record\"," +
+                "\"name\":\"ColorRecord\"," +
+                "\"namespace\":\"com.baeldung.apache.avro\"," +
+                "\"fields\":[{\"name\":\"color\",\"type\":{\"type\":\"enum\",\"name\":\"Color\"," +
+                "\"symbols\":[\"UNKNOWN\",\"GREEN\",\"RED\",\"BLUE\"]," +
+                "\"default\":\"UNKNOWN\"}}]}";
+
+        Schema originalRecordSchema = new Schema.Parser().parse(originalSchemaJson);
+
+        // Read with original schema
+        DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(evolvedRecordSchema, originalRecordSchema);
+        try (DataFileReader<GenericRecord> dataFileReader = new DataFileReader<>(file, datumReader)) {
+            GenericRecord result = dataFileReader.next();
+            assertEquals("UNKNOWN", result.get("color").toString());
+        }
+    }
+}