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import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.nio.MappedByteBuffer;import java.nio.channels.FileChannel;import java.security.MessageDigest;public final class Md5Util {		private static final char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c',			'd', 'e', 'f'};		public static String encode(File file) {		FileInputStream in = null;		MessageDigest md5 = null;		try {			in = new FileInputStream(file);			FileChannel ch = in.getChannel();			MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0, file.length());			md5 = MessageDigest.getInstance("MD5");			md5.update(byteBuffer);		} catch (Exception e) {			e.printStackTrace();		} finally {			try {				in.close();			} catch (IOException e) {				e.printStackTrace();			}		}		return toHex(md5.digest());	}	public static String encode(String arg) {		if (arg == null) {			arg = "";		}		MessageDigest md5 = null;		try {			md5 = MessageDigest.getInstance("MD5");			md5.update(arg.getBytes("UTF-8"));		} catch (Exception e) {			e.printStackTrace();		}		return toHex(md5.digest());	}	private static String toHex(byte[] bytes) {		StringBuffer str = new StringBuffer(32);		for (byte b : bytes) {			str.append(hexDigits[(b & 0xf0) >> 4]);			str.append(hexDigits[(b & 0x0f)]);		}		return str.toString();	}}

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