我将数据从一个活动发送到另一个活动。 但是获取错误空指针异常和应用程序崩溃。
错误 -
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.a98fit.neeraj.a98fit, PID: 31167
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.BaseBundle.getString(java.lang.String)' on a null object reference
at com.a98fit.neeraj.a98fit.Signup$1.onClick(Signup.java:118)
at android.view.View.performClick(View.java:5612)
at android.view.View$PerformClick.run(View.java:22285)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6123)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
Application terminated.
一项活动 - 我正在存储数据令牌＆amp; userId在数据库中并通过意图发送到另一个活动。
Intent intent1 = new Intent(Name.this, Signup.class);
intent1.putExtra("userId", userId);
intent1.putExtra("token",token);
startActivity(intent1);
另一项活动 - 我在哪里
Bundle bundle = getIntent().getExtras();
String token = bundle.getString("token").toString();
String userId= bundle.getString("userId");
一项活动---
public class Name extends AppCompatActivity {
private static final String TAG = Name.class.getSimpleName();
private Button btn_name_next;
EditText emailid,editTextUserName;
private ProgressDialog pDialog;
private SessionManager session;
private SQLiteHandler db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_name);
btn_name_next = (Button) findViewById(R.id.btn_name_next);
editTextUserName=(EditText) findViewById(R.id.editTextUserName);
final TelephonyManager tm = (TelephonyManager) getBaseContext().getSystemService(Context.TELEPHONY_SERVICE);
final String tmDevice, tmSerial, androidId;
tmDevice = "" + tm.getDeviceId();
tmSerial = "" + tm.getSimSerialNumber();
androidId = "" + Settings.Secure.getString(getContentResolver(), Settings.Secure.ANDROID_ID);
UUID deviceUuid = new UUID(androidId.hashCode(), ((long) tmDevice.hashCode() << 32) | tmSerial.hashCode());
final String deviceId = deviceUuid.toString();
Log.e(TAG, "Device Id: " + deviceId);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// Session manager
session = new SessionManager(getApplicationContext());
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(Name.this,
MakemeHealthy.class);
startActivity(intent);
finish();
}
btn_name_next.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name=editTextUserName.getText().toString();
if (name.length()==0) {
editTextUserName.setError("Tell us your name atleast");
}
else
{
//launchAgeScreen();
registerUser(name, deviceId);
}
}
});
}
private void registerUser(final String name, final String deviceId) {
// Tag used to cancel the request
String tag_string_req = "req_register";
pDialog.setMessage("Registering ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.NAME_REGISTER, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d(TAG, "Register Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean success = jObj.getBoolean("success");
//boolean error = jObj.getBoolean("error");
if (success) {
// User successfully stored in MySQL
// Now store the user in sqlite
//String uid = jObj.getString("uid");
String userId =jObj.getString("userId");
String token = jObj.getString("token");
db.addUser( token,userId);
//db.addUser(userId);
Intent intent1 = new Intent(Name.this, Signup.class);
intent1.putExtra("userId", userId);
intent1.putExtra("token",token);
startActivity(intent1);
Log.e(TAG, "token: " + token);
Log.e(TAG, "userId: " + userId);
Toast.makeText(getApplicationContext(), "User successfully registered. Try login now!", Toast.LENGTH_LONG).show();
// Launch login activity
Intent intent = new Intent(
Name.this,
Signup.class);
startActivity(intent);
finish();
} else {
// Error occurred in registration. Get the error
// message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Registration Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("name", name);
//params.put("email", email);
// params.put("password", password);
params.put("deviceId", deviceId);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
另一项活动 - 我发送数据。
protected void onCreate(Bundle savedInstanceState) {
//ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.READ_PHONE_STATE}, 1);
/* if(b!=null)
{
String token =(String) b.get("token");
String userId = (String) b.get("userId");
// Textv.setText(j);
}*/
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_signup);
TextView textViewlaer = (TextView) findViewById(R.id.textViewlater);
btn_name_make = (Button) findViewById(R.id.btn_name_make);
editTextEmailid = (EditText) findViewById(R.id.editTextEmailid);
passwordentry = (EditText) findViewById(R.id.passwordentry);
final TelephonyManager tm = (TelephonyManager) getBaseContext().getSystemService(Context.TELEPHONY_SERVICE);
final String tmDevice, tmSerial, androidId;
tmDevice = "" + tm.getDeviceId();
tmSerial = "" + tm.getSimSerialNumber();
androidId = "" + Settings.Secure.getString(getContentResolver(), Settings.Secure.ANDROID_ID);
UUID deviceUuid = new UUID(androidId.hashCode(), ((long) tmDevice.hashCode() << 32) | tmSerial.hashCode());
final String deviceId = deviceUuid.toString();
Log.e(TAG, "Device Id: " + deviceId);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// Session manager
session = new SessionManager(getApplicationContext());
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(Signup.this,
MakemeHealthy.class);
startActivity(intent);
finish();
}
// Make Me Awesome Button Click event
btn_name_make.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String email = editTextEmailid.getText().toString();
String password = passwordentry.getText().toString();
Bundle bundle = getIntent().getExtras();
String token = bundle.getString("token").toString();
String userId= bundle.getString("userId");
Log.e(TAG, "token: " + token);
Log.e(TAG, "userId: " + userId);
if (email.length() == 0) {
editTextEmailid.setError("Please Enter Email id");
} else if (!Patterns.EMAIL_ADDRESS.matcher(email).matches())
{
editTextEmailid.setError("Please enter Valid Email id");
} else if (password.length() == 0) {
passwordentry.setError("Please Enter password");
} else if (password.length() < 6) {
passwordentry.setError("Please Enter minimum 6 character");
} else {
registerUser(token,userId,email,password);
}
}
});
// I'll do it later Button Click event
textViewlaer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent doitlater = new Intent(Signup.this, Name.class);
startActivity(doitlater);
}
});
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}
答案 0 :(得分：3)
你在这里弄错了
startActivity(intent);
您将意图值置于意图中，并且启动活动为intent1。所以请通过intent1而不是intent
startActivity(intent1);// pass this intent1
使用此代码
Intent intent1 = new Intent(Name.this, Signup.class);
intent1.putExtra("userId", userId);
intent1.putExtra("token",token);
startActivity(intent1);
Log.e(TAG, "token: " + token);
Log.e(TAG, "userId: " + userId);
Toast.makeText(getApplicationContext(), "User successfully registered. Try login now!", Toast.LENGTH_LONG).show();
startActivity(intent1);
答案 1 :(得分：1)
您的Bundle为空：
试试这个：在第二个活动中获取数据
Intent i = getIntent();
String id = i.getStringExtra("userId");
String token = i.getStringExtra("token");
答案 2 :(得分：1)
您已在代码中两次调用Signup Actvity，请参阅代码中的以下代码。
Intent intent1 = new Intent(Name.this, Signup.class);
intent1.putExtra("userId", userId);
intent1.putExtra("token",token);
startActivity(intent1);
Log.e(TAG, "token: " + token);
Log.e(TAG, "userId: " + userId);
Toast.makeText(getApplicationContext(), "User successfully registered. Try login now!", Toast.LENGTH_LONG).show();
// Launch login activity
Intent intent = new Intent(Name.this,Signup.class);
startActivity(intent);
finish();
删除代码中Toast消息下方的代码。如下代码：
// Launch Signup activity
Intent intent1 = new Intent(Name.this, Signup.class);
intent1.putExtra("userId", userId);
intent1.putExtra("token",token);
startActivity(intent1);
Log.e(TAG, "token: " + token);
Log.e(TAG, "userId: " + userId);
Toast.makeText(getApplicationContext(), "User successfully registered. Try login now!", Toast.LENGTH_LONG).show();
finish();
答案 3 :(得分：0)
如果没有显示NullPointerException错误，请尝试这样：
Bundle bundle = getIntent().getExtras();
if(bundle !=null){
String token = bundle.getString("token").toString();
String userId= bundle.getString("userId");
}