aswi2020horky-gitlab/project/Deserializer/src/FileWorker.java @ 03a2d08f

import java.io.BufferedInputStream;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.zip.ZipException;
import java.util.zip.ZipInputStream;

public class FileWorker {
	
	public static byte[] loadByteArray(File file) throws IOException {
		byte buffer[];
		
		/*
		 * Note.
		 * For ZIP - the first four bytes should be one of the following combinations:
		 *     50 4B 03 04
		 *     50 4B 05 06 (empty archive)
		 *     50 4B 07 08 (spanned archive)
		 * Source: https://en.wikipedia.org/wiki/List_of_file_signatures
		 */
	    try {
	    	
	    	ZipInputStream zipIS = new ZipInputStream(new FileInputStream(file));
	    	
	        if (zipIS.getNextEntry() == null) {
	        	zipIS.close();
	        	throw new NoSuchElementException();
	        }
	        
	        System.out.println("The file is a zip archive...");
	        List<Byte> _buffer = new ArrayList<Byte>();
	        while (true) {
	        	int value = zipIS.read();
	        	if (value < 0) {
	        		break;
	        	} else {
	        		_buffer.add((byte) value);
	        	}
	        }
	        
	        buffer = new byte[_buffer.size()];
	        for (int i = 0; i < buffer.length; i++) {
	        	buffer[i] = _buffer.get(i);
	        }
	        
	        zipIS.close();
	        
		} catch (NoSuchElementException | ZipException e) {
			
			System.out.println("The file is not a zip archive...");
			buffer = new byte[(int) file.length()];
	    	BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
	    	bis.read(buffer);
			bis.close();
			
		}
	    
	    System.out.println("Bytes from the file were loaded correctly.");
	    return buffer;
	}

	public static boolean saveJson(File file, String json) {
        boolean retValue = false;
		try {
            FileWriter fw = new FileWriter(file);
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(json);
            bw.flush();
            bw.close();
            retValue = true;
        } catch (IOException e) {
            e.printStackTrace();
        }
		return retValue;
	}
	
}