import android.security.KeyChainAliasCallback; //导入依赖的package包/类
/**
 * Attempt to show the certificate selection dialog and shows the provided
 * CertSelectionFailureDialog if the platform's cert selection activity can't be found.
 */
@VisibleForTesting
static void maybeShowCertSelection(KeyChainCertSelectionWrapper keyChain,
        KeyChainAliasCallback callback, CertSelectionFailureDialog failureDialog) {
    try {
        keyChain.choosePrivateKeyAlias();
    } catch (ActivityNotFoundException e) {
        // This exception can be hit when a platform is missing the activity to select
        // a client certificate. It gets handled here to avoid a crash.
        // Complete the callback without selecting a certificate.
        callback.alias(null);
        // Show a dialog letting the user know that the system does not support
        // client certificate selection.
        failureDialog.show();
    }
}
 

import android.security.KeyChainAliasCallback; //导入依赖的package包/类
private void loadKeys(ICordovaClientCertRequest request) {
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(cordova.getActivity());
    final KeyChainAliasCallback callback = new AliasCallback(cordova.getActivity(), request);
    final String alias = sp.getString(SP_KEY_ALIAS, null);

    if (alias == null) {
        KeyChain.choosePrivateKeyAlias(cordova.getActivity(), callback, new String[]{"RSA"}, null, request.getHost(), request.getPort(), null);
    } else {
        ExecutorService threadPool = cordova.getThreadPool();
        threadPool.submit(new Runnable() {
            @Override
            public void run() {
                callback.alias(alias);
            }
        });
    }
}
 

import android.security.KeyChainAliasCallback; //导入依赖的package包/类
public KeyChainCertSelectionWrapper(Activity activity, KeyChainAliasCallback callback,
        String[] keyTypes, Principal[] principalsForCallback, String hostName, int port,
        String alias) {
    mActivity = activity;
    mCallback = callback;
    mKeyTypes = keyTypes;
    mPrincipalsForCallback = principalsForCallback;
    mHostName = hostName;
    mPort = port;
    mAlias = alias;
}