Java通货紧缩/通货膨胀流是如何工作的？

Question

测试数据:D8A8E00821608F227AE473774E177216

压缩数据:789C

解压缩数据：

我的程序：

SecureRandom random = new SecureRandom();
byte[] testdata = new byte[16];
random.nextBytes(testdata);
System.out.println("Test data: " + DatatypeConverter.printHexBinary(testdata));

byte[] compressed = null;
try (ByteArrayOutputStream buffer = new ByteArrayOutputStream())
{
   try (DeflaterOutputStream stream = new DeflaterOutputStream(buffer))
   {
      stream.write(testdata);
      stream.flush();
      compressed = buffer.toByteArray();
      System.out.println("Compressed data: " + DatatypeConverter.printHexBinary(compressed));
   }
}
catch (IOException e)
{
   System.out.println("IOException during compression.");
}

byte[] decompressed = null;
try (ByteArrayOutputStream buffer = new ByteArrayOutputStream())
{
   try (InflaterOutputStream stream = new InflaterOutputStream(buffer))
   {
      stream.write(compressed);
      stream.flush();
      decompressed = buffer.toByteArray();
      System.out.println("Decompressed data: " + DatatypeConverter.printHexBinary(decompressed));
   }
}
catch (IOException e)
{
   System.out.println("IOException during decompression.");
}

Answer 1

问题是，您只是在刷新流--这并不一定意味着没有更多的数据来，这可能会影响解压缩。

如果将flush()调用都更改为close()，您将看到您返回了适当的数据...或者在使用try-with-resources语句时，只需让它关闭内部流，然后调用TobyteArray:

try (ByteArrayOutputStream buffer = new ByteArrayOutputStream())
{
   try (DeflaterOutputStream stream = new DeflaterOutputStream(buffer))
   {
      stream.write(testdata);
   }
   compressed = buffer.toByteArray();
   System.out.println("Compressed data: " + Arrays.toString(compressed));
}
catch (IOException e)
{
   System.out.println("IOException during compression.");
}

（减压时同上。）