Java中的Deflate功能的等效Inflate

Question

I have a function for decompression in Java. I want same equivalent function for compression. Right now my deflate function gives altogether different output. Functions are as below:

        public static String compress(byte[] data) throws IOException {  
       Deflater deflater = new Deflater();
       deflater.setInput(data);    
       ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);   
       deflater.finish();  
       byte[] buffer = new byte[1024];   
       while (!deflater.finished()) {  
        int count = deflater.deflate(buffer); // returns the generated code... index  
        outputStream.write(buffer, 0, count);   
       }  
       outputStream.close();  
       byte[] output = outputStream.toByteArray();      
       return new String(Base64.getEncoder().encode(output));  
      }  

      public static String decompress(byte[] data) throws IOException, DataFormatException {  
       Inflater inflater = new Inflater(true);   
       inflater.setInput(data);  
       ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);  
       byte[] buffer = new byte[1024];  
       while (!inflater.finished()) {  
        int count = inflater.inflate(buffer);  
        outputStream.write(buffer, 0, count);  
       }  
       outputStream.close();  
       byte[] output = outputStream.toByteArray();  

       return new String(output); 
      }  

Using decompress function for "LcrJCYAwEEDRVlKBzmJmnNwELx4EW8haxRRvEOFfPrzzuSSamOtKthKgBaQEMAvH7QjqDLaoOE7C8JNElEg/EZ2iS61QtkbKuJeR5woz59FBWhduLw==" Gives "DPI65969|7/29/2019 12:00:00 AM|107|309.76|1|7/30/2019 1:22:27 AM|15|25|6cc0b4d27318bfa6cc6333afe06de63d"

But using "DPI65969|7/29/2019 12:00:00 AM|107|309.76|1|7/30/2019 1:22:27 AM|15|25|6cc0b4d27318bfa6cc6333afe06de63d" in compress function gives "eJwtyskJgDAQQNFWUoHOYmac3AQvHgRbyFrFFG8Q4V8+vPO5JJqY60q2EqAFpAQwC8ftCOoMtqg4TsLwk0SUSD8RnaJLrVC2Rsq4l5HnCjPn0UFaF24vAkwaGg==" But I am expecting same result on compression.

I don't want to change my decompression function as it's widely used somewhere else.

I am using these functions as below:

        public static void main(String[] args) 
        { 
            try{
                //Compress Block
             String strTocompress="DPI65969|7/29/2019 12:00:00 AM|107|309.76|1|7/30/2019 1:22:27 AM|15|25|6cc0b4d27318bfa6cc6333afe06de63d";   
             byte[] bytes = strTocompress.getBytes("ASCII");
             String encoded = compress(bytes);
             System.out.println(encoded); 
             //End of Compress Block
             //***********Decompress Block**************
             String strToDecompress="LcrJCYAwEEDRVlKBzmJmnNwELx4EW8haxRRvEOFfPrzzuSSamOtKthKgBaQEMAvH7QjqDLaoOE7C8JNElEg/EZ2iS61QtkbKuJeR5woz59FBWhduLw==";   
             byte[] bytes1 = Base64.getDecoder().decode(strToDecompress.getBytes());
             String decoded = decompress(bytes1);
             System.out.println(decoded); 
             //End of Decompress Block
            }       
            catch(Exception e)
            {
                System.out.println(e.getMessage());
            }
        } 

Answer 1

@Kartikeya You need to replace Deflater deflater = new Deflater(); line with Deflater deflater = new Deflater(Deflater.BEST_COMPRESSION,true); in your compress function.

 public static String compress(byte[] data) throws IOException {  
   Deflater deflater = new Deflater(Deflater.BEST_COMPRESSION,true);
   deflater.setInput(data);    
   ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);   
   deflater.finish();  
   byte[] buffer = new byte[1024];   
   while (!deflater.finished()) {  
    int count = deflater.deflate(buffer); // returns the generated code... index  
    outputStream.write(buffer, 0, count);   
   }  
   outputStream.close();  
   byte[] output = outputStream.toByteArray();      
   return new String(Base64.getEncoder().encode(output));  
  }  

Answer 2

    String s = "hello"; 
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    Deflater compresser = new Deflater(Deflater.BEST_COMPRESSION, true);
    DeflaterOutputStream deflaterOutputStream = new DeflaterOutputStream(stream, 
    compresser);
    deflaterOutputStream.write(s.getBytes());
    deflaterOutputStream.close();
    byte[] output= new Base64().encode(stream.toByteArray());
    String re1 = new String(output);