import java.security.InvalidKeyException;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.PrivateKey;import java.security.PublicKey;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import org.apache.commons.codec.binary.Base64;public class test {     public static final String CIPHER_ALGORITHM = "RSA/ECB/PKCS1Padding";     public static final String PLAIN_TEXT = "张三丰，您的2016年10月份工资金额为：8000元。";     public static final String KEY_ALGORITHM = "RSA";     /** RSA密钥长度必须是64的倍数，在512~65536之间。默认是1024 */     public static final int KEY_SIZE = 2048;     public static final String PUBLIC_KEY = "publicKey";     public static final String PRIVATE_KEY = "privateKey";            public static void main(String[] args) throws Exception     {        createKeyPairs();    }    public static void createKeyPairs() throws Exception     {          KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM);        keyPairGenerator.initialize(KEY_SIZE);        KeyPair keyPair = keyPairGenerator.generateKeyPair();        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();        //字符串化        byte[] pk = publicKey.getEncoded();          byte[] privk = privateKey.getEncoded();          String strpk = new String(Base64.encodeBase64(pk));          String strprivk = new String(Base64.encodeBase64(privk));                System.out.println("公钥:" + strpk);          System.out.println("私钥:" + strprivk);                //从字符串还原到对象        X509EncodedKeySpec pubX509 = new X509EncodedKeySpec(Base64.decodeBase64(strpk.getBytes()));          PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decodeBase64(strprivk.getBytes()));          KeyFactory keyf =  KeyFactory.getInstance(KEY_ALGORITHM);        PublicKey pubkey2 = keyf.generatePublic(pubX509);          PrivateKey privkey2 = keyf.generatePrivate(priPKCS8);                          //公钥加密        byte[] encodedText = RSAEncode(pubkey2, PLAIN_TEXT.getBytes());        System.out.println("加密后的密文: " + Base64.encodeBase64String(encodedText));                //私钥解密        System.out.println("解密后的明文: " + RSADecode(privkey2, encodedText));    }          public static byte[] RSAEncode(PublicKey key, byte[] plainText) {        try {            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);            cipher.init(Cipher.ENCRYPT_MODE, key);            return cipher.doFinal(plainText);        } catch (NoSuchAlgorithmException | NoSuchPaddingException                | InvalidKeyException | IllegalBlockSizeException                | BadPaddingException e) {            e.printStackTrace();        }        return null;    }    public static String RSADecode(PrivateKey key, byte[] encodedText) {        try {            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);            cipher.init(Cipher.DECRYPT_MODE, key);            return new String(cipher.doFinal(encodedText));        } catch (NoSuchAlgorithmException | NoSuchPaddingException                | InvalidKeyException | IllegalBlockSizeException                | BadPaddingException e) {            e.printStackTrace();        }        return null;    }}