android/guava/src/com/google/common/io/ByteSource.java
public boolean contentEquals(ByteSource other) throws IOException {
    checkNotNull(other);

    byte[] buf1 = createBuffer();
    byte[] buf2 = createBuffer();

    Closer closer = Closer.create();
    try {
      InputStream in1 = closer.register(openStream());
      InputStream in2 = closer.register(other.openStream());
      while (true) {
        int read1 = ByteStreams.read(in1, buf1, 0, buf1.length);
        int read2 = ByteStreams.read(in2, buf2, 0, buf2.length);
        if (read1 != read2 || !Arrays.equals(buf1, buf2)) {
          return false;
        } else if (read1 != buf1.length) {
          return true;
        }
      }
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }
public boolean contentEquals(ByteSource other) throws IOException {
    checkNotNull(other);

    byte[] buf1 = createBuffer();
    byte[] buf2 = createBuffer();

    Closer closer = Closer.create();
    try {
      InputStream in1 = closer.register(openStream());
      InputStream in2 = closer.register(other.openStream());
      while (true) {
        int read1 = ByteStreams.read(in1, buf1, 0, buf1.length);
        int read2 = ByteStreams.read(in2, buf2, 0, buf2.length);
        if (read1 != read2 || !Arrays.equals(buf1, buf2)) {
          return false;
        } else if (read1 != buf1.length) {
          return true;
        }
      }
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }
Checks that the contents of this byte source are equal to the contents of the given byte
source.

@throws IOException if an I/O error occurs while reading from this source or {@code other}