blob.java

Java的面向对象数据库系统的源代码

// $Id: BLOB.java,v 1.2 2003/11/23 14:16:53 per_nyfelt Exp $

import java.io.*;
import java.util.zip.*;

import org.ozoneDB.*;
import org.ozoneDB.blob.*;


public class BLOB {
    
    
    /** */
    public static void main( String[] _args ) throws Exception {
        String host = "localhost";
        int port = 3333;
        int SIZE = 1000 * 1024;
        
        // make a database connection
        RemoteDatabase db = new RemoteDatabase();
        try {
            db.open( host, port );
        } catch (Exception e) {
            System.out.println( "No ozone server found!" );
            System.exit( 0 );
        } 
        db.reloadClasses();
        System.out.println( "connected..." );
        
        // create a new BLOB
        System.out.println( "creating BLOB..." );
        String name = "BLOB1";
        BLOBContainer blob = (BLOBContainer)db.createObject( BLOBContainerImpl.class.getName(), 0, name );
        blob.init( 32 * 1024 );
        
        
        // block-write
        BLOBOutputStream out = new BLOBOutputStream( blob );
        CRC32 checksumOut = new CRC32();
        CheckedOutputStream checkedOut = new CheckedOutputStream( out, checksumOut );
        
        System.out.println( "\nblock-writing BLOB data... (size: " + SIZE + ")" );
        byte[] bufferOut = new byte[SIZE];
        for (int i = 0; i < SIZE; i++) {
            bufferOut[i] = (byte)i;
        } 
        
        long start = System.currentTimeMillis();
        checkedOut.write( bufferOut );
        long stop = System.currentTimeMillis();
        System.out.println( "   time: " + (stop - start) + "msec" );
        
        
        // block-read and verify
        System.out.print( "\nblock-reading BLOB data..." );
        BLOBInputStream in = new BLOBInputStream( blob );
        CRC32 checksumIn = new CRC32();
        CheckedInputStream checkedIn = new CheckedInputStream( in, checksumIn );
        
        start = System.currentTimeMillis();
        byte[] bufferIn = new byte[64 * 1024];
        int got;
        while ((got = checkedIn.read( bufferIn )) != -1) {
            System.out.print( "." );
            System.out.flush();
        } 
        stop = System.currentTimeMillis();
        System.out.println( "" );
        System.out.println( "   CRC-Out: " + checksumOut.getValue() );
        System.out.println( "   CRC-In:  " + checksumIn.getValue() );
        System.out.println( "   time: " + (stop - start) + "msec" );
        
        
        // buffered write
        out = new BLOBOutputStream( blob );
        BufferedOutputStream bout = new BufferedOutputStream( out, 32 * 1024 );
        DataOutputStream dataOut = new DataOutputStream( bout );
        
        System.out.println( "\nbuffered byte-writing BLOB data... (size: " + SIZE + ")" );
        start = System.currentTimeMillis();
        
        ExternalTransaction tx = db.newTransaction();
        tx.begin();
        for (int i = 0; i < SIZE; i++) {
            dataOut.writeByte( i );
        } 
        dataOut.flush();
        tx.commit();
        stop = System.currentTimeMillis();
        System.out.println( "   time: " + (stop - start) + "msec" );
        
        
        // buffered read and verify data
        System.out.println( "\nbuffered byte-reading BLOB data..." );
        in = new BLOBInputStream( blob );
        BufferedInputStream bin = new BufferedInputStream( in, 33 * 1024 );
        DataInputStream dataIn = new DataInputStream( bin );
        
        // read the BLOB data
        start = System.currentTimeMillis();
        tx = db.newTransaction();
        tx.begin();
        for (int i = 0; i < SIZE; i++) {
            int val = dataIn.readByte();
            if ((byte)val != (byte)i) {
                System.out.println( "   ERROR: position: " + i );
            } 
        } 
        tx.commit();
        stop = System.currentTimeMillis();
        System.out.println( "   time: " + (stop - start) + "msec" );
        
        
        // delete the BLOB
        System.out.println( "\ndeleting BLOB..." );
        db.deleteObject( blob );
    } 
}