Add ByteArrayResourceReader implementation that reads the data from a Resource (e.g. ClassPathResource) into a byte array.

Resolves gh-92.

spring-geode/src/test/java/org/springframework/geode/core/io/support/ByteArrayResourceReaderUnitTests.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *     https://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.springframework.geode.core.io.support;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.isA;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+
+import org.junit.Test;
+
+import org.springframework.core.io.Resource;
+
+/**
+ * Unit Tests for {@link ByteArrayResourceReader}.
+ *
+ * @author John Blum
+ * @see org.junit.Test
+ * @see org.mockito.Mockito
+ * @see org.springframework.core.io.Resource
+ * @see org.springframework.geode.core.io.support.ByteArrayResourceReader
+ * @since 1.3.1
+ */
+public class ByteArrayResourceReaderUnitTests {
+
+	@Test
+	public void doReadResourceReturnsByteArray() throws IOException {
+
+		byte[] data = { (byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE };
+
+		ByteArrayInputStream in = spy(new ByteArrayInputStream(data));
+
+		ByteArrayResourceReader reader = spy(new ByteArrayResourceReader());
+
+		Resource mockResource = mock(Resource.class);
+
+		doReturn(in).when(mockResource).getInputStream();
+		doReturn(2).when(reader).getBufferSize();
+
+		assertThat(reader.read(mockResource)).isEqualTo(data);
+
+		verify(mockResource, times(1)).getInputStream();
+		verify(in, times(1)).available();
+		verify(in, times(3)).read(isA(byte[].class));
+		verify(reader, times(1)).doRead(eq(in));
+	}
+
+	@Test
+	public void getBufferSizeIsDefault() {
+		assertThat(new ByteArrayResourceReader().getBufferSize())
+			.isEqualTo(ByteArrayResourceReader.DEFAULT_BUFFER_SIZE);
+	}
+}