code: public static PrivateKey getSignCertPrivateKeyByStoreMap(String certPath,
  			String certPwd) {
  		if (!keyStoreMap.containsKey(certPath)) {
  			loadSignCert(certPath, certPwd);
  		}
  		try {
  			Enumeration<String> aliasenum = keyStoreMap.get(certPath)
  					.aliases();
  			String keyAlias = null;
  			if (aliasenum.hasMoreElements()) {
  				keyAlias = aliasenum.nextElement();
  			}
  			PrivateKey privateKey = (PrivateKey) keyStoreMap.get(certPath)
  					.getKey(keyAlias, certPwd.toCharArray());
  			return privateKey;
  		} catch (KeyStoreException e) {
  			LogUtil.writeErrorLog("getSignCertPrivateKeyByStoreMap Error", e);
  			return null;
  		} catch (UnrecoverableKeyException e) {
  			LogUtil.writeErrorLog("getSignCertPrivateKeyByStoreMap Error", e);
  			return null;
  		} catch (NoSuchAlgorithmException e) {
  			LogUtil.writeErrorLog("getSignCertPrivateKeyByStoreMap Error", e);
  			return null;
  		}
  	}
docs: 通过指定路径的私钥证书  获取PrivateKey对象
  
  @return