JAVA 如何实现解密RSA算法并使用JS加密

import org.apache.commons.codec.binary.Base64;import javax.crypto.Cipher;import java.security.*;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;public class RSACoder {  public static final String KEY_ALGORITHM = "RSA";  public static final String SIGNATURE_ALGORITHM = "MD5withRSA";  private static final String PUBLIC_KEY = "RSAPublicKey";  private static final String PRIVATE_KEY = "RSAPrivateKey";  public static byte[] decryptBASE64(String key) {    return Base64.decodeBase64(key);  }  public static String encryptBASE64(byte[] bytes) {    return Base64.encodeBase64String(bytes);  }    public static String sign(byte[] data, String privateKey) throws Exception {    // 解密由base64编码的私钥    byte[] keyBytes = decryptBASE64(privateKey);    // 构造PKCS8EncodedKeySpec对象    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);    // KEY_ALGORITHM 指定的加密算法    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    // 取私钥匙对象    PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);    // 用私钥对信息生成数字签名    Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);    signature.initSign(priKey);    signature.update(data);    return encryptBASE64(signature.sign());  }    public static boolean verify(byte[] data, String publicKey, String sign)      throws Exception {    // 解密由base64编码的公钥    byte[] keyBytes = decryptBASE64(publicKey);    // 构造X509EncodedKeySpec对象    X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);    // KEY_ALGORITHM 指定的加密算法    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    // 取公钥匙对象    PublicKey pubKey = keyFactory.generatePublic(keySpec);    Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);    signature.initVerify(pubKey);    signature.update(data);    // 验证签名是否正常    return signature.verify(decryptBASE64(sign));  }  public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception{    // 对密钥解密    byte[] keyBytes = decryptBASE64(key);    // 取得私钥    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);    // 对数据解密    Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());    cipher.init(Cipher.DECRYPT_MODE, privateKey);    return cipher.doFinal(data);  }    public static byte[] decryptByPrivateKey(String data, String key)      throws Exception {    return decryptByPrivateKey(decryptBASE64(data),key);  }    public static byte[] decryptByPublicKey(byte[] data, String key)      throws Exception {    // 对密钥解密    byte[] keyBytes = decryptBASE64(key);    // 取得公钥    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    Key publicKey = keyFactory.generatePublic(x509KeySpec);    // 对数据解密    Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());    cipher.init(Cipher.DECRYPT_MODE, publicKey);    return cipher.doFinal(data);  }    public static byte[] encryptByPublicKey(String data, String key)      throws Exception {    // 对公钥解密    byte[] keyBytes = decryptBASE64(key);    // 取得公钥    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    Key publicKey = keyFactory.generatePublic(x509KeySpec);    // 对数据加密    Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());    cipher.init(Cipher.ENCRYPT_MODE, publicKey);    return cipher.doFinal(data.getBytes());  }    public static byte[] encryptByPrivateKey(byte[] data, String key)      throws Exception {    // 对密钥解密    byte[] keyBytes = decryptBASE64(key);    // 取得私钥    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);    KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);    Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);    // 对数据加密    Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());    cipher.init(Cipher.ENCRYPT_MODE, privateKey);    return cipher.doFinal(data);  }    public static String getPrivateKey(Map<String, Key> keyMap)      throws Exception {    Key key = (Key) keyMap.get(PRIVATE_KEY);    return encryptBASE64(key.getEncoded());  }    public static String getPublicKey(Map<String, Key> keyMap)      throws Exception {    Key key = keyMap.get(PUBLIC_KEY);    return encryptBASE64(key.getEncoded());  }    public static Map<String, Key> initKey() throws Exception {    KeyPairGenerator keyPairGen = KeyPairGenerator        .getInstance(KEY_ALGORITHM);    keyPairGen.initialize(1024);    KeyPair keyPair = keyPairGen.generateKeyPair();    Map<String, Key> keyMap = new HashMap(2);    keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥    keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥    return keyMap;  }}