InputStream unc = ld.getInputStream();
            OutputStream fOut = new BufferedOutputStream(new FileOutputStream(outFileName));

            Streams.pipeAll(unc, fOut);

            fOut.close();
        } else if (message instanceof PGPOnePassSignatureList) {
            throw new PGPException("encrypted message contains a signed message - not literal data.");
        } else {
            throw new PGPException("message is not a simple encrypted file - type unknown.");
        }

        if (pbe.isIntegrityProtected()) {
            if (!pbe.verify()) {
                System.err.println("message failed integrity check");
            } else {
                System.err.println("message integrity check passed");
            }
        } else {
            System.err.println("no message integrity check");
        }
    } catch (PGPException e) {
        System.err.println(e);
        if (e.getUnderlyingException() != null) {
            e.getUnderlyingException().printStackTrace();
        }
    }
}


private static byte[] compressFile(String fileName, int algorithm) throws IOException {
    ByteArrayOutputStream bOut = new ByteArrayOutputStream();
    PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(algorithm);
    PGPUtil.writeFileToLiteralData(comData.open(bOut), PGPLiteralData.BINARY,
            new File(fileName));
    comData.close();
    return bOut.toByteArray();
}


public static void encryptFile(
        String outputFileName,
        String inputFileName,
        String encKeyFileName,
        boolean armor,
        boolean withIntegrityCheck)
        throws IOException, NoSuchProviderException, PGPException {
    OutputStream out = new BufferedOutputStream(new FileOutputStream(outputFileName));
    PGPPublicKey encKey = readPublicKey(encKeyFileName);
    encryptFile(out, inputFileName, encKey, armor, withIntegrityCheck);
    out.close();
}

private static void encryptFile(
        OutputStream out,
        String fileName,
        PGPPublicKey encKey,
        boolean armor,
        boolean withIntegrityCheck)
        throws IOException, NoSuchProviderException {
    if (armor) {
        out = new ArmoredOutputStream(out);
    }

    try {
        byte[] bytes = compressFile(fileName, CompressionAlgorithmTags.ZIP);

        PGPEncryptedDataGenerator encGen = new PGPEncryptedDataGenerator(
                new JcePGPDataEncryptorBuilder(PGPEncryptedData.CAST5).setWithIntegrityPacket(withIntegrityCheck).setSecureRandom(new SecureRandom()).setProvider("BC"));

        encGen.addMethod(new JcePublicKeyKeyEncryptionMethodGenerator(encKey).setProvider("BC"));

        OutputStream cOut = encGen.open(out, bytes.length);

        cOut.write(bytes);
        cOut.close();

        if (armor) {
            out.close();
        }
    } catch (PGPException e) {
        System.err.println(e);
        if (e.getUnderlyingException() != null) {
            e.getUnderlyingException().printStackTrace();
        }
    }
}


private static PGPPublicKey readPublicKey(String fileName) throws IOException, PGPException {
    InputStream keyIn = new BufferedInputStream(new FileInputStream(fileName));
    PGPPublicKey pubKey = readPublicKey(keyIn);
    keyIn.close();
    return pubKey;
}

private 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.");
}

private static PGPPrivateKey findSecretKey(PGPSecretKeyRingCollection pgpSec, long keyID, char[] pass)
        throws PGPException, NoSuchProviderException {
    PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID);

    if (pgpSecKey == null) {
        return null;
    }

    return pgpSecKey.extractPrivateKey(new JcePBESecretKeyDecryptorBuilder().setProvider("BC").build(pass));
} }

# GPGDemo.java
* 替换掉 gpg public key 文件, gpg secret key文件, gpg password, 以及test.xml
* 运行GPGDemo后会发现test_decode.xml中的内容和test.xml中的内容一样
``` java
 package com.wzhonggo.util;

import org.bouncycastle.openpgp.*;
import java.io.*;
import java.security.NoSuchProviderException;

/**
 * Created by wzhonggo on 7/14/2017.
 */
public class GPGDemo {
        public static void main(String [] args) throws NoSuchProviderException, IOException, PGPException {
            String password ="gpgPassword";
            String gpgPublicKey="pubring.gpg"
            String gpgSecretKey="secring.gpg"
            GPGUtil.encryptFile("test_encode.xml", "test.xml", gpgPublicKey, false, false);
            GPGUtil.decryptFile("test_encode.xml",gpgSecretKey, password.toCharArray(), "test_decode.xml");
    }
}