import org.bouncycastle.openpgp.operator.PBEKeyEncryptionMethodGenerator; //导入依赖的package包/类
/**
 * Builds a PublicKeyKeyEncryptionMethodGenerator
 * for the specified key.
 */
protected PBEKeyEncryptionMethodGenerator buildSymmetricKeyEncryptor()
throws PGPException {
    if (log.isLoggable(Level.INFO))
        log.info("using symmetric encryption with " +
            keyDerivationAlgorithm + " hash, work factor " +
            keyDerivationWorkFactor);

    int algo = keyDerivationAlgorithm.ordinal();
    return new BcPBEKeyEncryptionMethodGenerator(
        symmetricPassphrase.toCharArray(),
        new BcPGPDigestCalculatorProvider().get(algo),
        keyDerivationWorkFactor);
}
 

import org.bouncycastle.openpgp.operator.PBEKeyEncryptionMethodGenerator; //导入依赖的package包/类
/**
 * Provide a user defined source of randomness.
 *
 * @param random  the secure random to be used.
 * @return  the current generator.
 */
public PBEKeyEncryptionMethodGenerator setSecureRandom(SecureRandom random)
{
    super.setSecureRandom(random);

    return this;
}
 

import org.bouncycastle.openpgp.operator.PBEKeyEncryptionMethodGenerator; //导入依赖的package包/类
public PBEKeyEncryptionMethodGenerator setSecureRandom(SecureRandom random)
{
    super.setSecureRandom(random);

    return this;
}