code: private static void initSignCert() {
  		if(!"01".equals(SDKConfig.getConfig().getSignMethod())){
  			LogUtil.writeLog("非rsa签名方式，不加载签名证书。");
  			return;
  		}
  		if (SDKConfig.getConfig().getSignCertPath() == null 
  				|| SDKConfig.getConfig().getSignCertPwd() == null
  				|| SDKConfig.getConfig().getSignCertType() == null) {
  			LogUtil.writeErrorLog("WARN: " + SDKConfig.SDK_SIGNCERT_PATH + "或" + SDKConfig.SDK_SIGNCERT_PWD 
  					+ "或" + SDKConfig.SDK_SIGNCERT_TYPE + "为空。 停止加载签名证书。");
  			return;
  		}
  		if (null != keyStore) {
  			keyStore = null;
  		}
  		try {
  			keyStore = getKeyInfo(SDKConfig.getConfig().getSignCertPath(),
  					SDKConfig.getConfig().getSignCertPwd(), SDKConfig
  							.getConfig().getSignCertType());
  			LogUtil.writeLog("InitSignCert Successful. CertId=["
  					+ getSignCertId() + "]");
  		} catch (IOException e) {
  			LogUtil.writeErrorLog("InitSignCert Error", e);
  		}
  	}
docs: 用配置文件acp_sdk.properties中配置的私钥路径和密码 加载签名证书