Seite 12: Listing 8

Inhaltsverzeichnis

Listing 8: Die CFileEncrypter-Klasse

package net.nieden.FileCrypter;

import java.io.*;
import java.util.*;
import javax.crypto.*;

public class CFileEncrypter implements IFileProcessInterrupter {
    private int blocks2Go, bufSizeKB;
    private IFileProgressIndicator pgrsIndicator=null;
    private File iFile;
    private boolean compression=false, multiThreaded=false, 
        storePasswd=false, is7zip=false;
    Boolean canceled=false;
    private String passwd;
    private Cipher ecipher;

    public CFileEncrypter(File f, int bufSizeKB, String passwd) 
          throws Exception {
        this.bufSizeKB=bufSizeKB;
        this.passwd=passwd;
        this.multiThreaded=false;
        blocks2Go=(int)f.length()/(bufSizeKB*1024);
        if (f.length()%((bufSizeKB*1024))>0) blocks2Go++;
        this.iFile=f;
        ecipher=CFileTools.initEncryption(passwd);
    }

    public void processFile() throws Exception {
        if (canceled) return;
        String fileOutputName;
        CFileBlockProcessor blockProc=null;
        FileInputStream fis=new FileInputStream(iFile);
        FileOutputStream fos=new FileOutputStream
            ((fileOutputName=String.format("ENCRY_%012x.bin",
                new Date().getTime())));
        CFileHeader hdr=new CFileHeader(bufSizeKB, compression,
            iFile, ecipher, (storePasswd)?passwd:null);
        hdr.writeHdr(fos);
        if (multiThreaded)
            blockProc=new CFileBlockProcessor(blocks2Go, 
               true, pgrsIndicator);
        for (int i=0;i<blocks2Go;i++) {
            byte[] iBuffer=CFileTools.readFromInputStream(fis, 
               bufSizeKB*1024);
            if (iBuffer==null) break;
            if (multiThreaded) {
                for (;;) {
                    // wait for free thread ...
                    if (canceled) break;
                    int count=blockProc.getWorkingThreadCount();
                    if (count < blockProc.maxThreads) {
                       blockProc.blockProcThreadList.get(i)
                         .startWorking(iBuffer, compression, 
                           is7zip,passwd, fos);
                        break;
                    }
                    Thread.sleep(100);
                }
            } else {
                if (canceled) break;
                if (compression) iBuffer=CFileTools.compressBlock
                    (iBuffer, is7zip);
                byte[] oBuffer=CFileTools.encryptBlock(ecipher, iBuffer);
                CFileTools.writeLengthToFile(oBuffer.length, fos);
                fos.write(oBuffer, 0, oBuffer.length);
                if (canceled) break;
                if (pgrsIndicator != null) {
                    if (!pgrsIndicator.progressIndicator(i, blocks2Go))
                        break;
                }
            }
            if (canceled) break;
        }
        fis.close();
        if (!canceled && multiThreaded) {
            // wait for last block to finish
            blockProc.waitForLastBlock();
        }
        fos.close();
        if (canceled) {
            new File(fileOutputName).delete();
        }
    }

    public void interrupt() {
        synchronized (canceled) {
            canceled=true;
        }
    }

    public int getNumberOfBlocksToProcess() {
        return blocks2Go;
    }

    public void setCompression(boolean compression) {
        setCompression(compression, false);
    }

    public void setCompression(boolean compression, boolean is7zip) {
        this.compression=compression;
        this.is7zip=is7zip;
    }

    public void setMultiThreaded(boolean multiThreaded) {
        this.multiThreaded=multiThreaded;
    }

    public void setStorePasswd(boolean storePasswd) {
        this.storePasswd=storePasswd;
    }

    public void setProgressIndicator(IFileProgressIndicator prgsIndicator) {
        this.pgrsIndicator=prgsIndicator;
    }
}


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