java - 压缩字符串长度比原始字符串长度稍大？

Question

我创建了一个使用 inflator 和 deflator 压缩和解压缩字符串的应用程序。当在简单的单词语句上测试并压缩成长度小于原始字符串长度的字符串时，应用程序工作正常，但问题是当我尝试使用加密字符串时，我得到的压缩字符串长度略大于原始字符串长度.
谁能告诉我一些解决方案？

    private String compress(String stringToCompress) throws UnsupportedEncodingException
    {
        byte[] compressedData = new byte[1024];
        byte[] stringAsBytes = stringToCompress.getBytes("UTF-8");

        Deflater compressor = new Deflater();
        compressor.setInput(stringAsBytes);
        compressor.finish();
        int compressedDataLength = compressor.deflate(compressedData);

        byte[] bytes = Arrays.copyOf(compressedData, compressedDataLength);
        return Base64.encodeBase64String(bytes);
    }

    private String decompressToString(String base64String) throws UnsupportedEncodingException, DataFormatException
    {
        byte[] compressedData = Base64.decodeBase64(base64String);

        Inflater deCompressor = new Inflater();
        deCompressor.setInput(compressedData, 0, compressedData.length);
        byte[] output = new byte[102400];
        int decompressedDataLength = deCompressor.inflate(output);
        deCompressor.end();

        return new String(output, 0, decompressedDataLength, "UTF-8");
    }

时间

public static void main(String[] args)    
        {
         Sample_class = new Sample_class();
         S String strToBeCompressed  = "Pehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya intezaar Kar loon main kPehla nasha Pehla khumaar Naya pyaar hai naya intezaar Kar loon main kya apna haal Aye dil-e-bekaraar Mere dil-e-bekaraar Tu hi bata Pehla nasha Pehla khumaar Udta hi firoon in hawaon mein kahin Ya main jhool jaoon in ghataon mein kahin Udta hi firoon in hawaon mein kahin Ya main jhool jaoon in ghataon mein kahin ";

         System.out.println(strToBeCompressed);
         String compressedData  = m.compress(strToBeCompressed);
         String deCompressedString = m.decompressToString(compressedData);
         System.out.println("Original     :: " + strToBeCompressed.length());
         System.out.println("Compressed   :: " + compressedData.toString().length());
         System.out.println("decompressed :: " + deCompressedString.length());
        }

输出

Pehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai nayaPehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya Pehla nasha Pehla khumaar Naya pyaar hai naya intezaar Kar loon main kPehla nasha Pehla khumaar Naya pyaar hai naya intezaar Kar loon main kya apna haal Aye dil-e-bekaraar Mere dil-e-bekaraar Tu hi bata Pehla nasha Pehla khumaar Udta hi firoon in hawaon mein kahin Ya main jhool jaoon in ghataon mein kahin Udta hi firoon in hawaon mein kahin Ya main jhool jaoon in ghataon mein kahin 
Original     :: 980
Compressed   :: 212
decompressed :: 980

但是当

    public static void main(String[] args)    
    {
     Sample_class = new Sample_class();
     String strToBeCompressed = "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";

     System.out.println(strToBeCompressed);
     String compressedData  = m.compress(strToBeCompressed);
     String deCompressedString = m.decompressToString(compressedData);
     System.out.println("Original     :: " + strToBeCompressed.length());
     System.out.println("Compressed   :: " + compressedData.toString().length());
     System.out.println("decompressed :: " + deCompressedString.length());
    }

输出

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
Original     :: 1032
Compressed   :: 1076
decompressed :: 1032

Answer 1

数据压缩利用数据中的模式，这些模式可以使用较短的模式进行编码。这基于模式存在的假设。如果没有找到模式，完美的压缩方案将保持数据不变。不幸的是，大多数压缩方案都会添加少量元数据以至少定义方案。你看到的可能就是这种情况。

想象一下试图压缩已经压缩的数据。当然，您不会期望这会进一步减小它的大小。