Refactor

.github/workflows/maven.yml

@@ -0,0 +1,18 @@
+name: Java CI
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '11'
+      - name: Build with Maven
+        run: mvn -B test

pom.xml

@@ -17,6 +17,11 @@
                     <target>7</target>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.22.2</version>
+            </plugin>
         </plugins>
     </build>
 
@@ -46,5 +51,11 @@
             <artifactId>avro</artifactId>
             <version>1.10.0</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
-</project>
+</project>

src/main/java/com.instarsocial.parquet/App.java → src/main/java/com/instarsocial/parquet/App.java

@@ -23,35 +23,37 @@ public static void main(String[] args) {
         DateTime dateTime = new DateTime(2020, 6, 1, 0, 0, 0, 0, DateTimeZone.UTC);
 
         for(int i = 0; i < 2; i++) {
-            generateParquetFileFor(dateTime.plusDays(i));
+            try {
+                generateParquetFileFor(dateTime.plusDays(i));
+            } catch (Exception e) {
+                e.printStackTrace(System.out);
+            }
         }
     }
 
-    private static void generateParquetFileFor(DateTime dateTime) {
-        try {
-            Schema schema = parseSchema();
-            DateTimeFormatter fmt = DateTimeFormat.forPattern("yyyyMMdd");
-            Path path = new Path("data_" + dateTime.toString(fmt) + ".parquet");
-
-            List<GenericData.Record> recordList = generateRecords(schema, dateTime);
-
-            try (ParquetWriter<GenericData.Record> writer = AvroParquetWriter.<GenericData.Record>builder(path)
-                    .withSchema(schema)
-                    .withCompressionCodec(CompressionCodecName.SNAPPY)
-                    .withRowGroupSize(ParquetWriter.DEFAULT_BLOCK_SIZE)
-                    .withPageSize(ParquetWriter.DEFAULT_PAGE_SIZE)
-                    .withConf(new Configuration())
-                    .withValidation(false)
-                    .withDictionaryEncoding(false)
-                    .build()) {
-
-                for (GenericData.Record record : recordList) {
-                    writer.write(record);
-                }
+    public static Path generateParquetFileFor(DateTime dateTime) throws Exception {
+        Schema schema = parseSchema();
+        DateTimeFormatter fmt = DateTimeFormat.forPattern("yyyyMMdd");
+        Path path = new Path("data_" + dateTime.toString(fmt) + ".parquet");
+
+        List<GenericData.Record> recordList = generateRecords(schema, dateTime);
+
+        try (ParquetWriter<GenericData.Record> writer = AvroParquetWriter.<GenericData.Record>builder(path)
+                .withSchema(schema)
+                .withCompressionCodec(CompressionCodecName.SNAPPY)
+                .withRowGroupSize(ParquetWriter.DEFAULT_BLOCK_SIZE)
+                .withPageSize(ParquetWriter.DEFAULT_PAGE_SIZE)
+                .withConf(new Configuration())
+                .withValidation(false)
+                .withDictionaryEncoding(false)
+                .build()) {
+
+            for (GenericData.Record record : recordList) {
+                writer.write(record);
             }
-        } catch (Exception ex) {
-            ex.printStackTrace(System.out);
         }
+
+        return path;
     }
 
     private static Schema parseSchema() {
@@ -87,4 +89,4 @@ private static List<GenericData.Record> generateRecords(Schema schema, DateTime
 
         return recordList;
     }
-}
+}

src/test/java/com/instarsocial/parquet/AppTest.java

@@ -0,0 +1,55 @@
+package com.instarsocial.parquet;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.nio.charset.StandardCharsets;
+import static org.junit.Assert.*;
+
+/**
+ * Tests for {@link App} using the Arrange-Act-Assert pattern.
+ */
+
+public class AppTest {
+
+    /** Temporary file generated by the test. */
+    private static File generatedFile;
+
+    @BeforeClass
+    public static void beforeAll() {
+        generatedFile = null;
+    }
+
+    @AfterClass
+    public static void afterAll() {
+        if (generatedFile != null && generatedFile.exists()) {
+            generatedFile.delete();
+        }
+    }
+
+    @Test
+    public void Should_CreateParquetFile_When_CallingGenerateParquetFileFor() throws Exception {
+        // Arrange
+        DateTime dateTime = new DateTime(2020, 6, 1, 0, 0, 0, 0, DateTimeZone.UTC);
+
+        // Act
+        org.apache.hadoop.fs.Path actual = App.generateParquetFileFor(dateTime);
+
+        // Assert
+        assertNotNull("Path should not be null", actual);
+        generatedFile = new File(actual.toString());
+        assertTrue("Generated file should exist", generatedFile.exists());
+
+        try (FileInputStream fis = new FileInputStream(generatedFile)) {
+            byte[] magic = new byte[4];
+            int read = fis.read(magic);
+            assertEquals(4, read);
+            assertEquals("PAR1", new String(magic, StandardCharsets.US_ASCII));
+        }
+    }
+}