// Zip.java
import java.io.*;
import java.util.zip.*;
import COM.ibm.db2.app.*;

public class Zip extends UDF {
   static final int BUFFER =  2048 ;
   
   public void zip(Clob clob, Blob b) throws Exception {
     b = Lob.newBlob();
     ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(b.getOutputStream()));
     char ca[] = new char[BUFFER];
     byte ba[] = new byte[ 2 *BUFFER];
     BufferedReader in = new BufferedReader(clob.getReader(), BUFFER);
     ZipEntry entry = new ZipEntry(".");
     zos.putNextEntry(entry);
     int count;
     while((count = in.read(ca,  0 , BUFFER)) != - 1 ) {
       for (int i= 0 ; i<count; i++) {
       	  ba[ 2 *i]   = (byte)(ca[i] & 0xff);
         ba[ 2 *i+ 1 ] = (byte)(ca[i] >>  8  & 0xff);
       }
       zos.write(ba,  0 ,  2 *count);
     }
     in.close();
     zos.close();
     set( 2 , b);
   }
   
   public void unzip(Blob b, Clob clob) throws Exception {
     clob = Lob.newClob(); 
     ZipInputStream zis = new ZipInputStream(new BufferedInputStream(b.getInputStream()));
     Writer out = clob.getWriter();
     if(zis.getNextEntry() != null) {
     	 char ca[] = new char[BUFFER];
    	 byte ba[] = new byte[ 2 *BUFFER];
       int count;
       while((count = zis.read(ba,  0 ,  2 *BUFFER)) != - 1 ) {
      	 for (int i= 0 ; i<count/ 2 ; i++) {
      		 ca[i] = (char)(((ba[ 2 *i+ 1 ] & 0xff) <<  8 ) | (ba[ 2 *i] & 0xff));
      	 }
         out.write(ca,  0 , count/ 2 );
       }
     }  
     zis.close();
     out.close();
     set( 2 , clob);
  }
}   

create function zip(c clob(2m))
RETURNS blob(1m)
LANGUAGE java
EXTERNAL NAME 'Zip.zip'
FENCED THREADSAFE
NO SQL
NOT NULL CALL
NO EXTERNAL ACTION
DISALLOW PARALLEL
PARAMETER STYLE db2general;

create function unzip(c blob(1m))
RETURNS clob(2m)
LANGUAGE java
EXTERNAL NAME 'Zip.unzip'
FENCED THREADSAFE
NO SQL
NOT NULL CALL
NO EXTERNAL ACTION
DISALLOW PARALLEL
PARAMETER STYLE db2general;