我可能误解了这种方法的预期行为，但这就是我试图使用它的目的：
- 用户成功登录 - 用户完全关闭应用程序（也在后台关闭） - 用户再次打开应用程序并且不必再次登录，因为 CognitoCachingCredentialsProvider 可以在设备上本地检查以查看她仍然登录
我尝试完成此操作的方法是在提示登录之前检查 getCachedIdentityId() 返回的内容。如果它返回非空值，则意味着她仍在登录，因为没有任何东西可以从设备中清除她的凭据。这是我的框架的样子。我正在使用开发人员认证的方法：
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import org.json.JSONException;
import org.json.JSONObject;
import android.content.Context;
import android.util.Log;
import com.amazonaws.auth.AWSAbstractCognitoIdentityProvider;
import com.amazonaws.auth.CognitoCachingCredentialsProvider;
import com.amazonaws.mobileconnectors.cognito.*;
import com.amazonaws.regions.Regions;
public class Util {
private final static String TAG = "Util";
private static final String AWS_ACCOUNT_ID = {acct id};
private static final String COGNITO_POOL_ID = {pool id};
private static final String COGNITO_ROLE_AUTH = {auth arn};
private static final String COGNITO_ROLE_UNAUTH = {unauth arn}
private static CognitoCachingCredentialsProvider sCredProvider;
private static UserIdentityProvider sIdProvider;
private static CognitoSyncManager sSyncManager;
private Util() {
}
public static CognitoCachingCredentialsProvider getCredProvider(
Context context) {
if (sCredProvider == null) {
if (sIdProvider == null) {
CognitoCachingCredentialsProvider tmpProvider = new CognitoCachingCredentialsProvider(
context.getApplicationContext(), AWS_ACCOUNT_ID,
COGNITO_POOL_ID, COGNITO_ROLE_UNAUTH,
COGNITO_ROLE_AUTH, Regions.US_EAST_1);
if (tmpProvider.getCachedIdentityId() != null) {
sCredProvider = tmpProvider;
} else {
sCredProvider = null;
}
} else {
sCredProvider = new CognitoCachingCredentialsProvider(
context.getApplicationContext(), sIdProvider,
COGNITO_ROLE_UNAUTH, COGNITO_ROLE_AUTH);
Map logins = new HashMap();
logins.put({Developer Provider Name}, sIdProvider.getToken());
sCredProvider.setLogins(logins);
}
}
return sCredProvider;
}
public static UserIdentityProvider getIdentityProvider(Context context,
String email, String pwd) {
if (sIdProvider == null) {
sIdProvider = new UserIdentityProvider(AWS_ACCOUNT_ID,
COGNITO_POOL_ID, context.getApplicationContext());
}
return sIdProvider;
}
public static boolean isLoggedIn(Context context) {
if (getCredProvider(context) == null) {
return false;
}
return true;
}
protected static class UserIdentityProvider extends
AWSAbstractCognitoIdentityProvider {
private Context context;
private String email;
private String password;
public UserIdentityProvider(String accountId, String identityPoolId,
Context c) {
super(accountId, identityPoolId);
context = c;
email = em;
password = pwd;
}
@Override
public String refresh() {
try {
ServerCommunicator server = new ServerCommunicator(context);
if (email != null && password != null) {
//this is a server call, which makes the call GetOpenIdTokenForDeveloperIdentityRequest after I authenticate the user and send AWS my user's token
String response = server.initUserLoginAsyncTask()
.execute(email, password).get();
prefs.setAllUserSharedPrefs(response);
JSONObject responseJSON = new JSONObject(response);
String identityId = responseJSON.getString("id");
String token = responseJSON.getString("token");
if (token != null && identityId != null) {
this.setToken(token);
this.setIdentityId(identityId);
update(identityId, token);
return token;
}
}
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
public String getProviderName() {
return {Developer Provider Name};
}
}
}
我只是从这个类中调用 isLoggedIn 方法来查看本地是否存储了 IdentityId。但是，这并没有按预期工作。我可以从调试中看到 getCachedIdentityId 始终为空（即使在初始化 CognitoCachingCredentialsProvider 并将令牌添加到登录映射之后也是如此），并且每当我在关闭应用程序后打开应用程序时，总是提示我再次登录。IdentityId 什么时候实际存储在本地，我的逻辑通常是否正确？
附加代码
import java.util.concurrent.ExecutionException;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class LoginActivity extends Activity {
private final String TAG = "LoginActivity";
private EditText etEmail, etPwd;
private Button bLogin, bGoToRegister;
private ServerCommunicator server;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i(TAG, "onCreate");
server = new ServerCommunicator(this);
if (Util.isLoggedIn(this)) {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
return;
}
this.setContentView(R.layout.activity_login);
etEmail = (EditText) findViewById(R.id.etEmail);
etPwd = (EditText) findViewById(R.id.etPassword);
bLogin = (Button) findViewById(R.id.bLogin);
bGoToRegister = (Button) findViewById(R.id.bGoToRegister);
bLogin.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String email = etEmail.getText().toString();
String pwd = etPwd.getText().toString();
Util.getIdentityProvider(v.getContext()).setEmail(email);
Util.getIdentityProvider(v.getContext()).setPassword(pwd);
String token = Util.getIdentityProvider(v.getContext()).refresh();
if (token != null) {
Intent intent = new Intent(v.getContext(), MainActivity.class);
startActivity(intent);
} else {
Toast.makeText(v.getContext(), "Invalid username/password",
Toast.LENGTH_SHORT).show();
}
}
});
}
}
以上是我的LoginActivity。当应用程序启动 MainActivity 时，我的 onCreate 方法开头有以下代码段：
if (!Util.isLoggedIn(this)) {
Intent intent = new Intent(this, LoginActivity.class);
startActivity(intent);
}
此调用初始化 CognitoCachingCredentialsProvider。我假设这将是 IdentityId 被缓存的时候，但我的调试显示即使在这个块之后，getCachedIdentityId() 仍然返回 null。我是如何尝试使用此类的吗？