fabric-gataway-java每次连接到区块链网络时client的身份都会改变的问题

之前写的登录逻辑

//判断账号密码
enroll = caClient.enroll(walletName, loginForm.getPassword());
Identity user = Identities.newX509Identity(orgEnum.getMspId(), enroll);
wallet.put(walletName, user);
//判断是否有证书，但if不可能为true
if (wallet.get(walletName) == null){
    throw new CoinException("Invalid walletName or Password!");
}

现在的登录逻辑

//判断账号密码
enroll = caClient.enroll(walletName, loginForm.getPassword());
//账号密码正确，再判断是否有证书
if (wallet.get(walletName) == null){
    Identity user = Identities.newX509Identity(orgEnum.getMspId(), enroll);
    wallet.put(walletName, user);
}

每次enroll时，无论账号密码是否改变，得到的Enrollment都会变化，证书文件也会发生改变，导致每次登录的时候都会对账号对应的证书重写。