Deflator and Inflator problem

Question

I use Deflator and Inflator to compress and decompress String for minimizing the size of the data to be sent in a network system.
I wrote a class (DataCompressor.java) to do it.
When i try to use it to compress and decompress within a single program (TestDataCompressor.java), it's all right.
But when i try to compress a String in (DCClient.java), and sent the compressed String to (DCServer.java), there are exception in decompressing the compressed String
My paltform is Windows2000 and JDK1.31
Anyone know what is the problem i got?
DataCompressor.java
import java.util.zip.Deflater;
import java.util.zip.Inflater;
import java.util.zip.DataFormatException;
import java.io.UnsupportedEncodingException;
public class DataCompressor
private Deflater DF = new Deflater(Deflater.HUFFMAN_ONLY,true);
private Inflater IF = new Inflater(true);
private int BUFFER_SIZE = 2048;
private byte[] compressbytes;
private byte[] decompressbytes;
private String encoding = "UTF-16LE";
public DataCompressor()
compressbytes = new byte[BUFFER_SIZE];
decompressbytes = new byte[BUFFER_SIZE];
public DataCompressor(int bsize)
BUFFER_SIZE = bsize;
compressbytes = new byte[BUFFER_SIZE];
decompressbytes = new byte[BUFFER_SIZE];
synchronized public String compress(String inputString)
int len;
DF.reset();
try
DF.setInput(inputString.getBytes(encoding));
DF.finish();
len = DF.deflate(compressbytes);
return new String(compressbytes,0,len,encoding);
catch(UnsupportedEncodingException UEE)
UEE.printStackTrace();
return "";
synchronized public String decompress(String inputString)
int len;
IF.reset();
try
IF.setInput(inputString.getBytes(encoding));
len = IF.inflate(decompressbytes);
return new String(decompressbytes,0,len,encoding);
catch(UnsupportedEncodingException UEE)
UEE.printStackTrace();
return "";
catch(DataFormatException DFE)
DFE.printStackTrace();
return "";
synchronized void clear()
DF.end();
IF.end();
DF = null;
IF = null;
compressbytes = null;
decompressbytes = null;
TestDataCompressor.java
import java.io.*;
public class TestDataCompressor
public static void main(String[] args)
String Data1 = "this is a test for data compression";
String EnData1 = "";
String DeData1 = "";
DataCompressor DC = new DataCompressor();
EnData1 = DC.compress(Data1);
System.out.println("Out 1 :\n"+EnData1);
DeData1 = DC.decompress(EnData1);
System.out.println("Decom 1 :\n"+DeData1);
DC.clear();
DC = null;
DCClient.java
import java.io.*;
import java.net.*;
public class DCClient
public static void main(String[] args) throws IOException
Socket S = new Socket("127.0.0.1",9090);
PrintWriter PW = new PrintWriter(S.getOutputStream(),true);
String Data = "this is a test for data compression";
String EnData = "";
DataCompressor DC = new DataCompressor();
EnData = DC.compress(Data);
PW.println(EnData);
System.out.println(EnData);
System.out.println(EnData.length()+" chars sent");
try
byte[] D = EnData.getBytes("UTF-16LE");
for(int i=0;i<D.length;i++)
System.out.println(D+" : "+(char)D);
catch(UnsupportedEncodingException UEE)
UEE.printStackTrace();
S.close();
S = null;
System.exit(0);
DCServer.java
import java.io.*;
import java.net.*;
public class DCServer
public static void main(String[] args) throws IOException
ServerSocket SS = new ServerSocket(9090);
Socket S;
BufferedReader BR;
String message = "";
DataCompressor DC = new DataCompressor();
while(true)
S = SS.accept();
BR = new BufferedReader(new InputStreamReader(S.getInputStream()));
while((message = BR.readLine())!=null)
System.out.println(message);
System.out.println(message.length() +" chars received.");
try
byte[] D = message.getBytes("UTF-16LE");
for(int i=0;i<D.length;i++)
System.out.println(D+" : "+(char)D);
catch(UnsupportedEncodingException UEE)
UEE.printStackTrace();
System.out.println("Decompressed : "+DC.decompress(message));
}

Answer 1

This is a guess from a puurely cursory glance at your code. I thought I saw you using readline() to get compressed data off the wire. That is probably the wrong thing to do, as the data is not character data.