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Java example source code file (ByteStreamsTest.java)

This example Java source code file (ByteStreamsTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytearraydatainput, bytearraydataoutput, bytearrayinputstream, bytearrayoutputstream, eofexception, fileoutputstream, illegalstateexception, indexoutofboundsexception, inputstream, ioexception, override, slowskipper, this, util, writablebytechannel

The ByteStreamsTest.java Java example source code

/*
 * Copyright (C) 2007 The Guava 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
 *
 * http://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 com.google.common.io;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.base.Charsets;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.Arrays;

/**
 * Unit test for {@link ByteStreams}.
 *
 * @author Chris Nokleberg
 */
public class ByteStreamsTest extends IoTestCase {

  public void testCopyChannel() throws IOException {
    byte[] expected = newPreFilledByteArray(100);
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    WritableByteChannel outChannel = Channels.newChannel(out);

    ReadableByteChannel inChannel =
        Channels.newChannel(new ByteArrayInputStream(expected));
    ByteStreams.copy(inChannel, outChannel);
    assertEquals(expected, out.toByteArray());
  }

  public void testCopyFileChannel() throws IOException {
    final int chunkSize = 14407; // Random prime, unlikely to match any internal chunk size
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    WritableByteChannel outChannel = Channels.newChannel(out);

    File testFile = createTempFile();
    FileOutputStream fos = new FileOutputStream(testFile);
    byte[] dummyData = newPreFilledByteArray(chunkSize);
    try {
      for (int i = 0; i < 500; i++) {
        fos.write(dummyData);
      }
    } finally {
      fos.close();
    }
    ReadableByteChannel inChannel = new RandomAccessFile(testFile, "r").getChannel();
    try {
      ByteStreams.copy(inChannel, outChannel);
    } finally {
      inChannel.close();
    }
    byte[] actual = out.toByteArray();
    for (int i = 0; i < 500 * chunkSize; i += chunkSize) {
      assertEquals(dummyData, Arrays.copyOfRange(actual, i, i + chunkSize));
    }
  }

  public void testReadFully() throws IOException {
    byte[] b = new byte[10];

    try {
      ByteStreams.readFully(newTestStream(10), null, 0, 10);
      fail("expected exception");
    } catch (NullPointerException e) {
    }

    try {
      ByteStreams.readFully(null, b, 0, 10);
      fail("expected exception");
    } catch (NullPointerException e) {
    }

    try {
      ByteStreams.readFully(newTestStream(10), b, -1, 10);
      fail("expected exception");
    } catch (IndexOutOfBoundsException e) {
    }

    try {
      ByteStreams.readFully(newTestStream(10), b, 0, -1);
      fail("expected exception");
    } catch (IndexOutOfBoundsException e) {
    }

    try {
      ByteStreams.readFully(newTestStream(10), b, 0, -1);
      fail("expected exception");
    } catch (IndexOutOfBoundsException e) {
    }

    try {
      ByteStreams.readFully(newTestStream(10), b, 2, 10);
      fail("expected exception");
    } catch (IndexOutOfBoundsException e) {
    }

    try {
      ByteStreams.readFully(newTestStream(5), b, 0, 10);
      fail("expected exception");
    } catch (EOFException e) {
    }

    Arrays.fill(b, (byte) 0);
    ByteStreams.readFully(newTestStream(10), b, 0, 0);
    assertEquals(new byte[10], b);

    Arrays.fill(b, (byte) 0);
    ByteStreams.readFully(newTestStream(10), b, 0, 10);
    assertEquals(newPreFilledByteArray(10), b);

    Arrays.fill(b, (byte) 0);
    ByteStreams.readFully(newTestStream(10), b, 0, 5);
    assertEquals(new byte[]{0, 1, 2, 3, 4, 0, 0, 0, 0, 0}, b);
  }

  public void testSkipFully() throws IOException {
    byte[] bytes = newPreFilledByteArray(100);
    skipHelper(0, 0, new ByteArrayInputStream(bytes));
    skipHelper(50, 50, new ByteArrayInputStream(bytes));
    skipHelper(50, 50, new SlowSkipper(new ByteArrayInputStream(bytes), 1));
    skipHelper(50, 50, new SlowSkipper(new ByteArrayInputStream(bytes), 0));
    skipHelper(100, -1, new ByteArrayInputStream(bytes));
    try {
      skipHelper(101, 0, new ByteArrayInputStream(bytes));
      fail("expected exception");
    } catch (EOFException e) {
    }
  }

  private static void skipHelper(long n, int expect, InputStream in)
      throws IOException {
    ByteStreams.skipFully(in, n);
    assertEquals(expect, in.read());
    in.close();
  }

  private static final byte[] bytes =
      new byte[] { 0x12, 0x34, 0x56, 0x78, 0x76, 0x54, 0x32, 0x10 };

  public void testNewDataInput_empty() {
    byte[] b = new byte[0];
    ByteArrayDataInput in = ByteStreams.newDataInput(b);
    try {
      in.readInt();
      fail("expected exception");
    } catch (IllegalStateException expected) {
    }
  }

  public void testNewDataInput_normal() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    assertEquals(0x12345678, in.readInt());
    assertEquals(0x76543210, in.readInt());
    try {
      in.readInt();
      fail("expected exception");
    } catch (IllegalStateException expected) {
    }
  }

  public void testNewDataInput_readFully() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    byte[] actual = new byte[bytes.length];
    in.readFully(actual);
    assertEquals(bytes, actual);
  }

  public void testNewDataInput_readFullyAndThenSome() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    byte[] actual = new byte[bytes.length * 2];
    try {
      in.readFully(actual);
      fail("expected exception");
    } catch (IllegalStateException ex) {
      assertThat(ex.getCause()).isInstanceOf(EOFException.class);
    }
  }

  public void testNewDataInput_readFullyWithOffset() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    byte[] actual = new byte[4];
    in.readFully(actual, 2, 2);
    assertEquals(0, actual[0]);
    assertEquals(0, actual[1]);
    assertEquals(bytes[0], actual[2]);
    assertEquals(bytes[1], actual[3]);
  }

  public void testNewDataInput_readLine() {
    ByteArrayDataInput in = ByteStreams.newDataInput(
        "This is a line\r\nThis too\rand this\nand also this".getBytes(Charsets.UTF_8));
    assertEquals("This is a line", in.readLine());
    assertEquals("This too", in.readLine());
    assertEquals("and this", in.readLine());
    assertEquals("and also this", in.readLine());
  }

  public void testNewDataInput_readFloat() {
    byte[] data = {0x12, 0x34, 0x56, 0x78, 0x76, 0x54, 0x32, 0x10};
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals(Float.intBitsToFloat(0x12345678), in.readFloat(), 0.0);
    assertEquals(Float.intBitsToFloat(0x76543210), in.readFloat(), 0.0);
  }

  public void testNewDataInput_readDouble() {
    byte[] data = {0x12, 0x34, 0x56, 0x78, 0x76, 0x54, 0x32, 0x10};
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals(Double.longBitsToDouble(0x1234567876543210L), in.readDouble(), 0.0);
  }

  public void testNewDataInput_readUTF() {
    byte[] data = new byte[17];
    data[1] = 15;
    System.arraycopy("Kilroy was here".getBytes(Charsets.UTF_8), 0, data, 2, 15);
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals("Kilroy was here", in.readUTF());
  }

  public void testNewDataInput_readChar() {
    byte[] data = "qed".getBytes(Charsets.UTF_16BE);
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals('q', in.readChar());
    assertEquals('e', in.readChar());
    assertEquals('d', in.readChar());
  }

  public void testNewDataInput_readUnsignedShort() {
    byte[] data = {0, 0, 0, 1, (byte) 0xFF, (byte) 0xFF, 0x12, 0x34};
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals(0, in.readUnsignedShort());
    assertEquals(1, in.readUnsignedShort());
    assertEquals(65535, in.readUnsignedShort());
    assertEquals(0x1234, in.readUnsignedShort());
  }

  public void testNewDataInput_readLong() {
    byte[] data = {0x12, 0x34, 0x56, 0x78, 0x76, 0x54, 0x32, 0x10};
    ByteArrayDataInput in = ByteStreams.newDataInput(data);
    assertEquals(0x1234567876543210L, in.readLong());
  }

  public void testNewDataInput_readBoolean() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    assertTrue(in.readBoolean());
  }

  public void testNewDataInput_readByte() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    for (int i = 0; i < bytes.length; i++) {
      assertEquals(bytes[i], in.readByte());
    }
    try {
      in.readByte();
      fail("expected exception");
    } catch (IllegalStateException ex) {
      assertThat(ex.getCause()).isInstanceOf(EOFException.class);
    }
  }

  public void testNewDataInput_readUnsignedByte() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes);
    for (int i = 0; i < bytes.length; i++) {
      assertEquals(bytes[i], in.readUnsignedByte());
    }
    try {
      in.readUnsignedByte();
      fail("expected exception");
    } catch (IllegalStateException ex) {
      assertThat(ex.getCause()).isInstanceOf(EOFException.class);
    }
  }

  public void testNewDataInput_offset() {
    ByteArrayDataInput in = ByteStreams.newDataInput(bytes, 2);
    assertEquals(0x56787654, in.readInt());
    try {
      in.readInt();
      fail("expected exception");
    } catch (IllegalStateException expected) {
    }
  }

  public void testNewDataInput_skip() {
    ByteArrayDataInput in = ByteStreams.newDataInput(new byte[2]);
    assertEquals(2, in.skipBytes(2));
    assertEquals(0, in.skipBytes(1));
  }

  public void testNewDataInput_BAIS() {
    ByteArrayInputStream bais = new ByteArrayInputStream(new byte[] {0x12, 0x34, 0x56, 0x78});
    ByteArrayDataInput in = ByteStreams.newDataInput(bais);
    assertEquals(0x12345678, in.readInt());
  }

  public void testNewDataOutput_empty() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    assertEquals(0, out.toByteArray().length);
  }

  public void testNewDataOutput_writeInt() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeInt(0x12345678);
    out.writeInt(0x76543210);
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_sized() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput(4);
    out.writeInt(0x12345678);
    out.writeInt(0x76543210);
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_writeLong() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeLong(0x1234567876543210L);
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_writeByteArray() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.write(bytes);
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_writeByte() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.write(0x12);
    out.writeByte(0x34);
    assertEquals(new byte[] {0x12, 0x34}, out.toByteArray());
  }

  public void testNewDataOutput_writeByteOffset() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.write(bytes, 4, 2);
    byte[] expected = {bytes[4], bytes[5]};
    assertEquals(expected, out.toByteArray());
  }

  public void testNewDataOutput_writeBoolean() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeBoolean(true);
    out.writeBoolean(false);
    byte[] expected = {(byte) 1, (byte) 0};
    assertEquals(expected, out.toByteArray());
  }

  public void testNewDataOutput_writeChar() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeChar('a');
    assertEquals(new byte[] {0, 97}, out.toByteArray());
  }

  // Hardcoded because of Android problems. See testUtf16Expected.
  private static final byte[] utf16ExpectedWithBom =
      new byte[] {-2, -1, 0, 114, 0, -55, 0, 115, 0, 117, 0, 109, 0, -55};

  public void testNewDataOutput_writeChars() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeChars("r\u00C9sum\u00C9");
    // need to remove byte order mark before comparing
    byte[] expected = Arrays.copyOfRange(utf16ExpectedWithBom, 2, 14);
    assertEquals(expected, out.toByteArray());
  }

  @AndroidIncompatible // https://code.google.com/p/android/issues/detail?id=196848
  public void testUtf16Expected() {
    byte[] hardcodedExpected = utf16ExpectedWithBom;
    byte[] computedExpected = "r\u00C9sum\u00C9".getBytes(Charsets.UTF_16);
    assertEquals(hardcodedExpected, computedExpected);
  }

  public void testNewDataOutput_writeUTF() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeUTF("r\u00C9sum\u00C9");
    byte[] expected ="r\u00C9sum\u00C9".getBytes(Charsets.UTF_8);
    byte[] actual = out.toByteArray();
    // writeUTF writes the length of the string in 2 bytes
    assertEquals(0, actual[0]);
    assertEquals(expected.length, actual[1]);
    assertEquals(expected, Arrays.copyOfRange(actual, 2, actual.length));
  }

  public void testNewDataOutput_writeShort() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeShort(0x1234);
    assertEquals(new byte[] {0x12, 0x34}, out.toByteArray());
  }

  public void testNewDataOutput_writeDouble() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeDouble(Double.longBitsToDouble(0x1234567876543210L));
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_writeFloat() {
    ByteArrayDataOutput out = ByteStreams.newDataOutput();
    out.writeFloat(Float.intBitsToFloat(0x12345678));
    out.writeFloat(Float.intBitsToFloat(0x76543210));
    assertEquals(bytes, out.toByteArray());
  }

  public void testNewDataOutput_BAOS() {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ByteArrayDataOutput out = ByteStreams.newDataOutput(baos);
    out.writeInt(0x12345678);
    assertEquals(4, baos.size());
    assertEquals(new byte[] {0x12, 0x34, 0x56, 0x78}, baos.toByteArray());
  }

  public void testToByteArray_withSize_givenCorrectSize() throws IOException {
    InputStream in = newTestStream(100);
    byte[] b = ByteStreams.toByteArray(in, 100);
    assertEquals(100, b.length);
  }

  public void testToByteArray_withSize_givenSmallerSize() throws IOException {
    InputStream in = newTestStream(100);
    byte[] b = ByteStreams.toByteArray(in, 80);
    assertEquals(100, b.length);
  }

  public void testToByteArray_withSize_givenLargerSize() throws IOException {
    InputStream in = newTestStream(100);
    byte[] b = ByteStreams.toByteArray(in, 120);
    assertEquals(100, b.length);
  }

  public void testToByteArray_withSize_givenSizeZero() throws IOException {
    InputStream in = newTestStream(100);
    byte[] b = ByteStreams.toByteArray(in, 0);
    assertEquals(100, b.length);
  }

  public void testExhaust() throws IOException {
    InputStream in = newTestStream(100);
    assertEquals(100, ByteStreams.exhaust(in));
    assertEquals(-1, in.read());
    assertEquals(0, ByteStreams.exhaust(in));

    InputStream empty = newTestStream(0);
    assertEquals(0, ByteStreams.exhaust(empty));
    assertEquals(-1, empty.read());
  }

  private static InputStream newTestStream(int n) {
    return new ByteArrayInputStream(newPreFilledByteArray(n));
  }

  /** Stream that will skip a maximum number of bytes at a time. */
  private static class SlowSkipper extends FilterInputStream {
    private final long max;

    public SlowSkipper(InputStream in, long max) {
      super(in);
      this.max = max;
    }

    @Override public long skip(long n) throws IOException {
      return super.skip(Math.min(max, n));
    }
  }

  public void testReadBytes() throws IOException {
    final byte[] array = newPreFilledByteArray(1000);
    assertEquals(array, ByteStreams.readBytes(
      new ByteArrayInputStream(array), new TestByteProcessor()));
  }

  private class TestByteProcessor implements ByteProcessor<byte[]> {
    private final ByteArrayOutputStream out = new ByteArrayOutputStream();

    @Override
    public boolean processBytes(byte[] buf, int off, int len)
        throws IOException {
      out.write(buf, off, len);
      return true;
    }

    @Override
    public byte[] getResult() {
      return out.toByteArray();
    }
  }

  public void testByteProcessorStopEarly() throws IOException {
    byte[] array = newPreFilledByteArray(10000);
    assertEquals((Integer) 42,
        ByteStreams.readBytes(new ByteArrayInputStream(array),
            new ByteProcessor<Integer>() {
              @Override
              public boolean processBytes(byte[] buf, int off, int len) {
                assertEquals(
                    copyOfRange(buf, off, off + len),
                    newPreFilledByteArray(8192));
                return false;
              }

              @Override
              public Integer getResult() {
                return 42;
              }
            }));
  }

  public void testNullOutputStream() throws Exception {
    // create a null output stream
    OutputStream nos = ByteStreams.nullOutputStream();
    // write to the output stream
    nos.write('n');
    String test = "Test string for NullOutputStream";
    nos.write(test.getBytes());
    nos.write(test.getBytes(), 2, 10);
    // nothing really to assert?
    assertSame(ByteStreams.nullOutputStream(), ByteStreams.nullOutputStream());
  }

  public void testLimit() throws Exception {
    byte[] big = newPreFilledByteArray(5);
    InputStream bin = new ByteArrayInputStream(big);
    InputStream lin = ByteStreams.limit(bin, 2);

    // also test available
    lin.mark(2);
    assertEquals(2, lin.available());
    int read = lin.read();
    assertEquals(big[0], read);
    assertEquals(1, lin.available());
    read = lin.read();
    assertEquals(big[1], read);
    assertEquals(0, lin.available());
    read = lin.read();
    assertEquals(-1, read);

    lin.reset();
    byte[] small = new byte[5];
    read = lin.read(small);
    assertEquals(2, read);
    assertEquals(big[0], small[0]);
    assertEquals(big[1], small[1]);

    lin.reset();
    read = lin.read(small, 2, 3);
    assertEquals(2, read);
    assertEquals(big[0], small[2]);
    assertEquals(big[1], small[3]);
  }

  public void testLimit_mark() throws Exception {
    byte[] big = newPreFilledByteArray(5);
    InputStream bin = new ByteArrayInputStream(big);
    InputStream lin = ByteStreams.limit(bin, 2);

    int read = lin.read();
    assertEquals(big[0], read);
    lin.mark(2);

    read = lin.read();
    assertEquals(big[1], read);
    read = lin.read();
    assertEquals(-1, read);

    lin.reset();
    read = lin.read();
    assertEquals(big[1], read);
    read = lin.read();
    assertEquals(-1, read);
  }

  public void testLimit_skip() throws Exception {
    byte[] big = newPreFilledByteArray(5);
    InputStream bin = new ByteArrayInputStream(big);
    InputStream lin = ByteStreams.limit(bin, 2);

    // also test available
    lin.mark(2);
    assertEquals(2, lin.available());
    lin.skip(1);
    assertEquals(1, lin.available());

    lin.reset();
    assertEquals(2, lin.available());
    lin.skip(3);
    assertEquals(0, lin.available());
  }

  public void testLimit_markNotSet() {
    byte[] big = newPreFilledByteArray(5);
    InputStream bin = new ByteArrayInputStream(big);
    InputStream lin = ByteStreams.limit(bin, 2);

    try {
      lin.reset();
      fail();
    } catch (IOException expected) {
      assertThat(expected).hasMessage("Mark not set");
    }
  }

  public void testLimit_markNotSupported() {
    InputStream lin = ByteStreams.limit(new UnmarkableInputStream(), 2);

    try {
      lin.reset();
      fail();
    } catch (IOException expected) {
      assertThat(expected).hasMessage("Mark not supported");
    }
  }

  private static class UnmarkableInputStream extends InputStream {
    @Override
    public int read() throws IOException {
      return 0;
    }

    @Override
    public boolean markSupported() {
      return false;
    }
  }

  private static byte[] copyOfRange(byte[] in, int from, int to) {
    byte[] out = new byte[to - from];
    for (int i = 0; i < to - from; i++) {
      out[i] = in[from + i];
    }
    return out;
  }

  // TODO(cpovirk): Inline this.
  private static void assertEquals(byte[] expected, byte[] actual) {
    assertThat(actual).isEqualTo(expected);
  }
}

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