@Test
public void test_read_processor() throws IOException {
  ArrayByteSource test = ArrayByteSource.copyOf(new byte[] {1, 2, 3});
  ByteProcessor<Integer> processor = new ByteProcessor<Integer>() {

    @Override
    public boolean processBytes(byte[] buf, int off, int len) throws IOException {
      assertThat(off).isEqualTo(0);
      assertThat(len).isEqualTo(3);
      assertThat(buf[0]).isEqualTo((byte) 1);
      assertThat(buf[1]).isEqualTo((byte) 2);
      assertThat(buf[2]).isEqualTo((byte) 3);
      return false;
    }

    @Override
    public Integer getResult() {
      return 123;
    }
  };
  assertThat(test.read(processor)).isEqualTo(123);
}
 

@Override
public <T> T read(ByteProcessor<T> processor) throws IOException {
  processor.processBytes(array, 0, array.length);
  return processor.getResult();
}