Merge pull request #16880 from AndreiBranza/master

BAEL-8043 | Handling default values in Avro

Author: theangrydev

apache-libraries-2/pom.xml

@@ -40,11 +40,54 @@
             <artifactId>camel-jackson</artifactId>
             <version>${camel.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.avro</groupId>
+            <artifactId>avro</artifactId>
+            <version>${apache.avro.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.fasterxml.jackson.core</groupId>
+                    <artifactId>jackson-core</artifactId>
+                </exclusion>
+                <exclusion>
+                    <groupId>com.fasterxml.jackson.core</groupId>
+                    <artifactId>jackson-databind</artifactId>
+                </exclusion>
+                <exclusion>
+                    <groupId>com.fasterxml.jackson.core</groupId>
+                    <artifactId>jackson-annotations</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.avro</groupId>
+                <artifactId>avro-maven-plugin</artifactId>
+                <version>${apache.avro.version}</version>
+                <configuration>
+                    <sourceDirectory>${project.basedir}/src/main/java/com/baeldung/avro/</sourceDirectory>
+                    <outputDirectory>${project.basedir}/src/main/java/com/baeldung/avro/</outputDirectory>
+                    <stringType>String</stringType>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>schema</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
     <properties>
         <javax.validation.validation-api.version>2.0.1.Final</javax.validation.validation-api.version>
         <camel.version>4.4.1</camel.version>
+        <apache.avro.version>1.11.3</apache.avro.version>
     </properties>
 
 </project>

apache-libraries-2/src/main/java/com/baeldung/avro/SerializationDeserializationLogic.java

@@ -0,0 +1,33 @@
+package com.baeldung.avro;
+
+import generated.avro.Car;
+
+import org.apache.avro.file.DataFileReader;
+import org.apache.avro.file.DataFileWriter;
+import org.apache.avro.io.DatumReader;
+import org.apache.avro.io.DatumWriter;
+import org.apache.avro.specific.SpecificDatumReader;
+import org.apache.avro.specific.SpecificDatumWriter;
+
+import java.io.File;
+import java.io.IOException;
+
+public class SerializationDeserializationLogic {
+
+    static void serializeCar(Car car) throws IOException {
+        DatumWriter<Car> userDatumWriter = new SpecificDatumWriter(Car.class);
+
+        try (DataFileWriter<Car> dataFileWriter = new DataFileWriter(userDatumWriter)) {
+            dataFileWriter.create(car.getSchema(), new File("cars.avro"));
+            dataFileWriter.append(car);
+        }
+    }
+
+    static Car deserializeCar() throws IOException {
+        DatumReader<Car> userDatumReader = new SpecificDatumReader(Car.class);
+
+        try (DataFileReader<Car> dataFileReader = new DataFileReader(new File("cars.avro"), userDatumReader)) {
+            return dataFileReader.next();
+        }
+    }
+}

apache-libraries-2/src/main/java/com/baeldung/avro/car.avsc

@@ -0,0 +1,19 @@
+{
+    "namespace": "generated.avro",
+    "type": "record",
+    "name": "Car",
+    "fields": [
+        {   "name": "brand",
+            "type": "string",
+            "default": "Dacia"
+         },
+        {   "name": "number_of_doors",
+            "type": "int",
+            "default": 4
+        },
+        {   "name": "color",
+            "type": ["null", "string"],
+            "default": null
+        }
+    ]
+}

apache-libraries-2/src/test/java/com/baeldung/avro/AvroDefaultValuesUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.avro;
+
+import generated.avro.Car;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class AvroDefaultValuesUnitTest {
+
+    @Test
+    public void givenCarJsonSchema_whenCarIsSerialized_thenCarIsSuccessfullyDeserialized() throws IOException {
+
+        Car car = Car.newBuilder()
+            .build();
+
+        SerializationDeserializationLogic.serializeCar(car);
+        Car deserializedCar = SerializationDeserializationLogic.deserializeCar();
+
+        assertEquals("Dacia", deserializedCar.getBrand());
+        assertEquals(4, deserializedCar.getNumberOfDoors());
+        assertNull(deserializedCar.getColor());
+    }
+}