GZIP application

import java.io.ByteArrayInputStream;  
import java.io.ByteArrayOutputStream;  
import java.io.IOException;  
import java.util.zip.GZIPInputStream;  
import java.util.zip.GZIPOutputStream;  
   
/**
 * Gzip compressed strings
 */  
public class GZIP {   
 /**
  * String compression
  * @param str String to be compressed
  * @return returns the compressed string
  * @throws IOException
  */  
 public static String compress(String str) throws IOException {  
     if (null == str || str.length() <= 0) {  
         return str;  
     }  
     // create a new output stream  
     ByteArrayOutputStream out = new ByteArrayOutputStream();  
     // Create new output stream with default buffer size  
     GZIPOutputStream gzip = new GZIPOutputStream(out);  
     // write bytes to this output stream  
     gzip.write(str.getBytes("utf-8")); //Because the default character set in the background may be the GBK character set, a character set needs to be specified here  
     gzip.close();  
     // Convert the buffer contents to a string by decoding the bytes using the specified charsetName  
     return out.toString("ISO-8859-1");  
 }  
   
 /**
  * Decompression of strings
  * @param str decompress the string
  * @return returns the decompressed string
  * @throws IOException
  */  
public static String unCompress(String str) throws IOException {  
     if (null == str || str.length() <= 0) {  
         return str;  
     }  
     // create a new output stream  
     ByteArrayOutputStream out = new ByteArrayOutputStream();  
     // Create a ByteArrayInputStream using buf as its buffer array  
     ByteArrayInputStream in = new ByteArrayInputStream(str.getBytes("ISO-8859-1"));  
     // Create new input stream with default buffer size  
     GZIPInputStream gzip = new GZIPInputStream(in);  
     byte[] buffer = new byte[256];  
     int n = 0;  
  
     // read uncompressed data into byte array  
     while ((n = gzip.read(buffer)) >= 0){  
           out.write(buffer, 0, n);  
     }  
     // Convert the buffer contents to a string by decoding the bytes using the specified charsetName   
     return out.toString("utf-8");   
     }  
}