diff --git a/spring-geode/src/main/java/org/springframework/geode/core/io/support/ByteArrayResourceReader.java b/spring-geode/src/main/java/org/springframework/geode/core/io/support/ByteArrayResourceReader.java new file mode 100644 index 00000000..da707a85 --- /dev/null +++ b/spring-geode/src/main/java/org/springframework/geode/core/io/support/ByteArrayResourceReader.java @@ -0,0 +1,75 @@ +/* + * 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 java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; + +import org.springframework.core.io.Resource; +import org.springframework.geode.core.io.AbstractResourceReader; +import org.springframework.lang.NonNull; + +/** + * A concrete {@link AbstractResourceReader} implementation that reads data from a target {@link Resource Resource's} + * {@link Resource#getInputStream() InputStream} into a byte array. + * + * @author John Blum + * @see java.io.InputStream + * @see java.io.ByteArrayOutputStream + * @see org.springframework.core.io.Resource + * @see org.springframework.geode.core.io.AbstractResourceReader + * @since 1.3.1 + */ +@SuppressWarnings("unused") +public class ByteArrayResourceReader extends AbstractResourceReader { + + protected static final int DEFAULT_BUFFER_SIZE = 32768; + + /** + * Returns the required {@link Integer#TYPE buffer size} used to capture data from the target {@link Resource} + * in chunks. + * + * Subclasses are encouraged to override this method as necessary to tune the buffer size. By default, the + * buffer size is {@literal 32K} or {@literal 32768} bytes. + * + * @return the required {@link Integer#TYPE buffer size} to read from the {@link Resource} in chunks. + */ + protected int getBufferSize() { + return DEFAULT_BUFFER_SIZE; + } + + /** + * @inheritDoc + */ + @Override + protected @NonNull byte[] doRead(@NonNull InputStream resourceInputStream) throws IOException { + + try (ByteArrayOutputStream out = new ByteArrayOutputStream(resourceInputStream.available())) { + + byte[] buffer = new byte[getBufferSize()]; + + for (int bytesRead = resourceInputStream.read(buffer); bytesRead != -1; bytesRead = resourceInputStream.read(buffer)) { + // using a buffer will trigger a flush() automatically in the OutputStream + out.write(buffer, 0, bytesRead); + } + + out.flush(); + + return out.toByteArray(); + } + } +} diff --git a/spring-geode/src/test/java/org/springframework/geode/core/io/support/ByteArrayResourceReaderUnitTests.java b/spring-geode/src/test/java/org/springframework/geode/core/io/support/ByteArrayResourceReaderUnitTests.java new file mode 100644 index 00000000..c341b048 --- /dev/null +++ b/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); + } +}