我尝试使用LZ4压缩来压缩字符串对象，但结果不利于LZ4 这是我尝试过的程序
public class CompressionDemo {
public static byte[] compressGZIP(String data) throws IOException {
long start = System.nanoTime ();
ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length());
GZIPOutputStream gzip = new GZIPOutputStream(bos);
gzip.write(data.getBytes());
gzip.close();
byte[] compressed = bos.toByteArray();
bos.close();
System.out.println(System.nanoTime()-start);
return compressed;
}
public static byte[] compressLZ4(String data) throws IOException {
long start = System.nanoTime ();
LZ4Factory factory = LZ4Factory.fastestJavaInstance();
LZ4Compressor compressor = factory.highCompressor();
byte[] result = compressor.compress(data.getBytes());
System.out.println(System.nanoTime()-start);
return result;
}
public static byte[] compressDeflater(String stringToCompress) {
long start = System.nanoTime ();
byte[] returnValues = null;
try {
Deflater deflater = new Deflater(Deflater.BEST_COMPRESSION);
deflater.setInput(stringToCompress.getBytes("UTF-8"));
deflater.finish();
byte[] bytesCompressed = new byte[Short.MAX_VALUE];
int numberOfBytesAfterCompression = deflater.deflate(bytesCompressed);
returnValues = new byte[numberOfBytesAfterCompression];
System.arraycopy(bytesCompressed, 0, returnValues, 0, numberOfBytesAfterCompression);
} catch (Exception uee) {
uee.printStackTrace();
}
System.out.println(System.nanoTime()-start);
return returnValues;
}
public static void main(String[] args) throws IOException, DataFormatException {
System.out
.println("..it’s usually most beneficial to compress anyway, and determine which payload (the compressed or the uncompressed one) has the smallest size and include a small token to indicate whether decompression is required."
.getBytes().length);
byte[] arr = compressLZ4("..it’s usually most beneficial to compress anyway, and determine which payload (the compressed or the uncompressed one) has the smallest size and include a small token to indicate whether decompression is required.");
System.out.println(arr.length);
}
}
我已经收集了上面的统计数据。但是LZ4并没有所说的那么快
请告诉我我哪里做错了。
最佳答案
你的结果没有意义，因为压缩前的大小太小。您正在尝试以超过 100MB/s 的速度测量几千字节的压缩情况。测量值会在 JVM 预热期间丢失。使用几 MB 的输入文件重试。您应该在此处获得与我的 LZ4 实现一致的数字:https://github.com/flanglet/kanzi/wiki/Compression-examples .
关于java - 与 deflater 压缩字符串相比，LZ4 并不快，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36352159/