import org.spongycastle.openpgp.PGPPublicKeyRingCollection; //导入依赖的package包/类
public static PGPPublicKey readPublicKeyFromCol(InputStream in) throws IOException, PGPException {
    in = PGPUtil.getDecoderStream(in);
    PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(in, new BcKeyFingerprintCalculator());
    PGPPublicKey key = null;
    Iterator<PGPPublicKeyRing> keyRings = pgpPub.getKeyRings();
    while (key == null && keyRings.hasNext()) {
        PGPPublicKeyRing keyRing = keyRings.next();
        Iterator<PGPPublicKey> keys = keyRing.getPublicKeys();
        while (keys.hasNext()) {
            PGPPublicKey k = keys.next();
            if (k.isEncryptionKey()) {
                key = k;
                break;
            }
        }
    }
    if (key == null)
        throw new PGPException("Can't find a valid encryption key in key ring.");

    return key;
}
 

import org.spongycastle.openpgp.PGPPublicKeyRingCollection; //导入依赖的package包/类
@SuppressWarnings("unchecked")
public static PGPPublicKey extractPublicKeyFromBytes(byte[] keyBlock) throws IOException, PGPException {
	PGPPublicKeyRingCollection keyringCol = new PGPPublicKeyRingCollection(PGPUtil.getDecoderStream(new ByteArrayInputStream(Base64.decode(keyBlock, Base64.DEFAULT))));
	PGPPublicKey key = null;
	Iterator<PGPPublicKeyRing> rIt = keyringCol.getKeyRings();
	while(key == null && rIt.hasNext()) {
		PGPPublicKeyRing keyring = (PGPPublicKeyRing) rIt.next();
		Iterator<PGPPublicKey> kIt = keyring.getPublicKeys();
		while(key == null && kIt.hasNext()) {
			PGPPublicKey k = (PGPPublicKey) kIt.next();
			if(k.isEncryptionKey())
				key = k;
		}
	}
	
	if(key == null) {
		throw new IllegalArgumentException("there isn't an encryption key here.");
	}

	return key;
}
 

import org.spongycastle.openpgp.PGPPublicKeyRingCollection; //导入依赖的package包/类
/**
 * A simple routine that opens a key ring file and loads the first available key
 * suitable for encryption.
 *
 * @param input data stream containing the public key data
 * @return the first public key found.
 * @throws IOException
 * @throws PGPException
 */
static PGPPublicKey readPublicKey(InputStream input) throws IOException, PGPException
{
    PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(
            PGPUtil.getDecoderStream(input), new JcaKeyFingerprintCalculator());

    //
    // we just loop through the collection till we find a key suitable for encryption, in the real
    // world you would probably want to be a bit smarter about this.
    //

    Iterator keyRingIter = pgpPub.getKeyRings();
    while (keyRingIter.hasNext())
    {
        PGPPublicKeyRing keyRing = (PGPPublicKeyRing)keyRingIter.next();

        Iterator keyIter = keyRing.getPublicKeys();
        while (keyIter.hasNext())
        {
            PGPPublicKey key = (PGPPublicKey)keyIter.next();

            if (key.isEncryptionKey())
            {
                return key;
            }
        }
    }

    throw new IllegalArgumentException("Can't find encryption key in key ring.");
}
 

import org.spongycastle.openpgp.PGPPublicKeyRingCollection; //导入依赖的package包/类
/**
    * A simple routine that opens a key ring file and loads the first available key
    * suitable for encryption.
    * 
    * @param input
    * @return
    * @throws IOException
    * @throws PGPException
    */
   @SuppressWarnings("rawtypes")
static PGPPublicKey readPublicKey(InputStream input) throws IOException, PGPException
   {
       PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(
           PGPUtil.getDecoderStream(input));

       //
       // we just loop through the collection till we find a key suitable for encryption, in the real
       // world you would probably want to be a bit smarter about this.
       //

       Iterator keyRingIter = pgpPub.getKeyRings();
       while (keyRingIter.hasNext())
       {
           PGPPublicKeyRing keyRing = (PGPPublicKeyRing)keyRingIter.next();

           Iterator keyIter = keyRing.getPublicKeys();
           while (keyIter.hasNext())
           {
               PGPPublicKey key = (PGPPublicKey)keyIter.next();

               if (key.isEncryptionKey())
               {
                   return key;
               }
           }
       }

       throw new IllegalArgumentException("Can't find encryption key in key ring.");
   }