保存/读取文件中公共/私有的键，保存读取文件私有,package net.

保存/读取文件中公共/私有的键，保存读取文件私有,package net.

package net.java;import java.io.*;import java.security.*;import java.security.spec.*;public class Adam {    public static void main(String args[]) {        Adam adam = new Adam();        try {            String path = "C:\\Documents and Settings\\george\\My Documents\\workspaces\\gsoc09\\playground\\tmp";            KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");            keyGen.initialize(1024);            KeyPair generatedKeyPair = keyGen.genKeyPair();            System.out.println("Generated Key Pair");            adam.dumpKeyPair(generatedKeyPair);            adam.SaveKeyPair(path, generatedKeyPair);            KeyPair loadedKeyPair = adam.LoadKeyPair(path, "DSA");            System.out.println("Loaded Key Pair");            adam.dumpKeyPair(loadedKeyPair);        } catch (Exception e) {            e.printStackTrace();            return;        }    }    private void dumpKeyPair(KeyPair keyPair) {        PublicKey pub = keyPair.getPublic();        System.out.println("Public Key: " + getHexString(pub.getEncoded()));        PrivateKey priv = keyPair.getPrivate();        System.out.println("Private Key: " + getHexString(priv.getEncoded()));    }    private String getHexString(byte[] b) {        String result = "";        for (int i = 0; i < b.length; i++) {            result += Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1);        }        return result;    }    public void SaveKeyPair(String path, KeyPair keyPair) throws IOException {        PrivateKey privateKey = keyPair.getPrivate();        PublicKey publicKey = keyPair.getPublic();        // Store Public Key.        X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(                publicKey.getEncoded());        FileOutputStream fos = new FileOutputStream(path + "/public.key");        fos.write(x509EncodedKeySpec.getEncoded());        fos.close();        // Store Private Key.        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(                privateKey.getEncoded());        fos = new FileOutputStream(path + "/private.key");        fos.write(pkcs8EncodedKeySpec.getEncoded());        fos.close();    }    public KeyPair LoadKeyPair(String path, String algorithm)            throws IOException, NoSuchAlgorithmException,            InvalidKeySpecException {        // Read Public Key.        File filePublicKey = new File(path + "/public.key");        FileInputStream fis = new FileInputStream(path + "/public.key");        byte[] encodedPublicKey = new byte[(int) filePublicKey.length()];        fis.read(encodedPublicKey);        fis.close();        // Read Private Key.        File filePrivateKey = new File(path + "/private.key");        fis = new FileInputStream(path + "/private.key");        byte[] encodedPrivateKey = new byte[(int) filePrivateKey.length()];        fis.read(encodedPrivateKey);        fis.close();        // Generate KeyPair.        KeyFactory keyFactory = KeyFactory.getInstance(algorithm);        X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(                encodedPublicKey);        PublicKey publicKey = keyFactory.generatePublic(publicKeySpec);        PKCS8EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(                encodedPrivateKey);        PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);        return new KeyPair(publicKey, privateKey);    }}