http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.mime;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.bouncycastle.util.Strings;


Read regular text lines, allowing for a single character look ahead.

/**
 * Read regular text lines, allowing for a single character look ahead.
 */
class LineReader
{
    private final InputStream src;

    private int lastC = -1;

    LineReader(InputStream src)
    {
        this.src = src;
    }

    String readLine()
        throws IOException
    {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();

        int ch;

        if (lastC != -1)
        {
            if (lastC == '\r')   // to get this we must have '\r\r' so blank line
            {
                return "";
            }
            ch = lastC;
            lastC = -1;
        }
        else
        {
            ch = src.read();
        }

        while (ch >= 0 && ch != '\r' && ch != '\n')
        {
            bOut.write(ch);
            ch = src.read();
        }

        if (ch == '\r')
        {
            int c = src.read();
            if (c != '\n' && c >= 0)
            {
                lastC = c;
            }
        }

        if (ch < 0)
        {
            return null;
        }

        return Strings.fromUTF8ByteArray(bOut.toByteArray());
    }
}