Deflater压缩包含0到99之间字节的字节数组（长度为100） 压缩的字节数组作为解压缩输入传递给Inflater。 解压缩器返回的长度缺少原始列表中的3个字节。
以下是代码：
byte orig[] = new byte[100];
IntStream.range(0, 100).forEach(i -> orig[i] = (byte) i);
System.out.println("OrigLength: " + orig.length);
byte[] compressed = new byte[orig.length];
Deflater deflater = new Deflater();
deflater.setInput(orig);
deflater.finish();
int compressedLength = deflater.deflate(compressed);
deflater.end();
System.out.println("--------------------------------------------------------------------");
System.out.println("CompressedLength::" + compressedLength);
for (int i = 0; i < compressedLength; i++) {
System.out.print(compressed[i] + " ");
}
Inflater decompresser = new Inflater();
decompresser.setInput(compressed, 0, compressedLength);
byte[] result = new byte[compressedLength];
int resultLength = decompresser.inflate(result);
decompresser.end();
System.out.println("\n--------------------------------------------------------------------");
System.out.println("DecompressedLength::" + resultLength);
for (int i = 0; i < resultLength; i++) {
System.out.print(result[i] + " ");
}
System.out.println("\n--------------------------------------------------------------------");
输出：
OrigLength：100
CompressedLength :: 100
120 -100 99 96 100 98 102 97 101 99 -25 -32 -28 -30 -26 -31 -27 -29 23 16 20 18 22 17 21 19 -105 -112 -108 -110 -106 -111 -107 -109 87 80 84 82 86 81 85 83 -41 -48 -44 -46 -42 -47 -43 -45 55 48 52 50 54 49 53 51 -73 -80 -76 -78 -74 -79 -75 -77 119 112 116 114 118 113 117 115 -9 -16 -12 -14＆gt; -10 -15 -11 -13 15 8 12 10 14 9 13 11 -113 -120 -116 -118 -114 -119 -115 -117 79 72
DecompressedLength :: 97
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
处理完成，退出代码为0
解压缩长度为97，原始长度为100.您能否建议我的代码有什么问题？
感谢。
答案 0 :(得分：1)
虽然不清楚，但我发现了以下内容，
有效的不是充气器，而是散热器。
压缩数据时的Deflater我惊奇地注意到字节数比原始未压缩数据增加。例如，上面的压缩数据数组有100个元素，因为数组的大小为100。
但是，如果我增加压缩数组大小（任意说200）然后使用该数组，那么deflate方法将返回一个值108（这里比原始100多8个字节）。这令我感到困惑，因为我理解我需要知道什么是deflate压缩以及算法是如何工作的，我正在经历它。
所以这是更新后的代码，
byte orig[] = new byte[100];
IntStream.range(0, 100).forEach(i -> orig[i] = (byte) i);
System.out.println("OrigLength: " + orig.length);
byte[] compressed = new byte[orig.length * 2]; // double it arbitrarily chosen
Deflater deflater = new Deflater();
deflater.setInput(orig);
deflater.finish();
int compressedLength = 0;
compressedLength = deflater.deflate(compressed);
deflater.end();
System.out.println("--------------------------------------------------------------------");
System.out.println("CompressedLength::" + compressedLength); //now this will be 108
for (int i = 0; i < compressedLength; i++) {
System.out.print(compressed[i] + " ");
}
Inflater decompresser = new Inflater();
byte[] result = new byte[orig.length];
decompresser.setInput(compressed, 0, compressedLength);
int resultLength = decompresser.inflate(result);
decompresser.end();
System.out.println("\n--------------------------------------------------------------------");
System.out.println("DecompressedLength::" + resultLength);
for (int i = 0; i < resultLength; i++) {
System.out.print(result[i] + " ");
}
System.out.println("\n--------------------------------------------------------------------");
输出：
OrigLength：100
CompressedLength :: 108 //这是关注点8字节额外
DecompressedLength :: 100
答案 1 :(得分：0)
你必须看看这个例子：
public static String compress(final String expanded) {
try {
byte[] input = expanded.getBytes("US-ASCII");
// Compress the bytes
byte[] output = new byte[input.length];
Deflater compresser = new Deflater();
compresser.setInput(input);
compresser.finish();
final int size = compresser.deflate(output);
return new String(output, 0, size, "US-ASCII");
} catch (Exception ne) {
ne.printStackTrace();
return null;
}
}
/**
* Inflate a string
* @param compressed
* @return Inflated string.
*/
public static String expand(final String compressed) {
try {
final byte[] output = compressed.getBytes("US-ASCII");
// Decompress the bytes
Inflater decompresser = new Inflater();
decompresser.setInput(output, 0, output.length);
byte[] result = new byte[output.length*2];
int resultLength = decompresser.inflate(result);
decompresser.end();
// Decode the bytes into a String
return new String(result, 0, resultLength, "US-ASCII");
} catch (Exception ne) {
ne.printStackTrace();
return null;
}
}
答案 2 :(得分：0)
您可以在这里找到一些想法：
private static byte[] readCompressed(final Repository db,
final AnyObjectId id) throws FileNotFoundException, IOException {
final FileInputStream objStream = new FileInputStream(db.toFile(id));
final byte[] compressed;
try {
compressed = new byte[objStream.available()];
int off = 0;
while (off < compressed.length)
off += objStream.read(compressed, off, compressed.length - off);
} finally {
objStream.close();
}
return compressed;
}