first commit

Author: ayonious

Hunzipping.java

@@ -0,0 +1,230 @@
+package project0805006;
+
+import java.util.*;
+import java.io.*;
+
+ 
+ 
+ 
+
+public class Lunzipping
+{
+	
+	public static int bitsz1;
+	
+	//byte er string representation in eight digit
+	public static String bttost[]=new String[256];
+	public static String big1;
+	
+	
+	
+	
+	
+/*============================================================
+ * make all the binary to string conversion for 8 bits
+ *=============================================================*/
+	public static void pre()
+	{
+		int i,j;
+		String r1;
+		bttost[0]="0";
+		for(i=0;i<256;i++)
+		{
+			r1="";
+			j=i;
+			if(i!=0) bttost[i]="";
+			while(j!=0)
+			{
+				if((j%2)==1) bttost[i]+="1";
+				else bttost[i]+="0";
+				j/=2;
+			}
+			for(j=bttost[i].length()-1;j>=0;j--)
+			{
+				r1+=bttost[i].charAt(j);
+			}
+			while(r1.length()<8)
+			{	
+				r1="0"+r1;
+			}
+			bttost[i]=r1;
+		}
+	}
+/*=========================================================================*/
+	
+	
+	
+	
+/*==========================================================================
+ * byte to int conversion
+ *=========================================================================*/
+	public static int btoi(Byte bt)
+	{
+		int ret=bt;
+		if(ret<0)
+			ret+=256;
+		return ret;
+			
+	}
+	
+/**======================================================================*/
+	
+	
+	
+/*==========================================================================
+ * byte to int conversion
+ *=========================================================================*/
+	public static int stoi(String s)
+	{
+		int ret=0,i;
+		for(i=0;i<s.length();i++)
+		{
+			ret*=2;
+			if(s.charAt(i)=='1') ret++;
+		}
+		return ret;		
+	}
+/**======================================================================*/
+	
+	
+	
+	public static void Lunzip(String fileis) 
+    {
+        int k;
+       	int dictSize = 256;
+       	int mpsz=256;
+       	String ts;
+        Map<Integer,String> dictionary = new HashMap<Integer,String>();
+        for (int i = 0; i < 256; i++)
+            dictionary.put(i, "" + (char)i);
+ 	  
+        String fileos=filei.substring(0,filei.length()-6);
+        
+        
+        File filei=null,fileo=null;
+        filei=new File(fileis);
+        fileo=new File(fileos);
+		try
+		{
+			FileInputStream file_input = new FileInputStream (filei);
+			DataInputStream data_in    = new DataInputStream (file_input);
+			FileOutputStream file_output = new FileOutputStream (fileo);
+			DataOutputStream data_out    = new DataOutputStream (file_output);
+			
+					
+			Byte  c;
+			bitsz1=data_in.readInt();
+			
+			
+		
+			while(true)
+			{
+				try 
+				{	
+				  	c=data_in.readByte();
+      				big1+=bttost[btoi(c)];
+      				if(big1.length()>=bitsz1)
+      					break;
+				}
+				catch (EOFException eof){System.out.println ("End of File");break;} 
+			}
+			
+			
+			if(big1.length()>=bitsz1)
+			{
+				k=stoi(big1.substring(0,bitsz1));
+				big1=big1.substring(bitsz1,big1.length());
+			}
+			else
+			{
+				data_in.close();
+				data_out.close();
+				return;
+			}
+			
+			
+			String w = "" + (char)k;
+        	
+			
+			data_out.writeBytes(w);
+			//System.out.println(w);
+			
+			
+			while(true)
+			{
+				try 
+				{	
+					while(big1.length()<bitsz1)
+					{
+						c=data_in.readByte();
+      					big1+=bttost[btoi(c)];
+					}
+					k=stoi(big1.substring(0,bitsz1));
+					big1=big1.substring(bitsz1,big1.length());
+					
+					
+					String entry="";
+		            if (dictionary.containsKey(k))
+		            {
+		            	
+		                entry = dictionary.get(k);
+		            }
+		            else if (k == dictSize)
+		            {
+		            	entry = w + w.charAt(0);
+		            	
+		            }
+		            data_out.writeBytes(entry);
+		 		
+		            if(mpsz<100000)
+ 			        {
+ 			        	ts=w + entry.charAt(0);		                
+		                dictionary.put(dictSize++,ts);
+		                mpsz+=ts.length();
+	                }
+		            w = entry;
+				}
+				catch (EOFException eof){System.out.println ("End of File");break;} 
+			}
+			data_in.close();
+			data_out.close();
+			file_input.close();
+			file_output.close();
+		}
+		catch (IOException e) {System.out.println ("IO exception = " + e );}
+		
+		
+		filei=null;
+        fileo=null;
+		
+    }
+
+
+
+
+	
+	public static void beginLunzipping(String arg1) 
+    {
+    	big1="";
+    	bitsz1=0;
+    	pre();
+    	Lunzip(arg1);
+    	big1="";
+    	bitsz1=0;
+    }
+
+
+
+
+	/*
+    public static void main(String[] args) 
+    {
+    	big1="";
+    	bitsz1=0;
+    	pre();
+    	Lunzip("in.txt.LmZWp");
+    	big1="";
+    	bitsz1=0;
+    }
+    */
+}