json.decode() Unexpected end of input (at character 1) - http

Question

I am facing a anonymus closure error in flutter while signing in a user. It worked a few days before but now its not working, I dont no why. So please help and thanks in advance..Whenever i fill the details and tap on the signin button it throws the below error---
E/flutter ( 2914): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 2914): FormatException: Unexpected end of input (at character 1)
E/flutter ( 2914):
E/flutter ( 2914): ^
E/flutter ( 2914):
E/flutter ( 2914): #0 _ChunkedJsonParser.fail (dart:convert/runtime/libconvert_patch.dart:1358:5)
E/flutter ( 2914): #1 _ChunkedJsonParser.close (dart:convert/runtime/libconvert_patch.dart:511:7)
E/flutter ( 2914): #2 _parseJson (dart:convert/runtime/libconvert_patch.dart:30:10)
E/flutter ( 2914): #3 JsonDecoder.convert (dart:convert/json.dart:540:36)
E/flutter ( 2914): #4 JsonCodec.decode (dart:convert/json.dart:167:41)
E/flutter ( 2914): #5 _SignInState._login.<anonymous closure> (package:restaurant_app/signin.dart:81:23)
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:restaurant_app/globalVar.dart';
import 'package:restaurant_app/homescreen.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:restaurant_app/signup.dart';
import 'package:http/http.dart' as http;
import 'package:flutter_html_view/html_parser.dart';
class SignIn extends StatefulWidget {
#override
_SignInState createState() => _SignInState();
}
class _SignInState extends State<SignIn> with SingleTickerProviderStateMixin
{
TabController controller;
TextEditingController _email = new TextEditingController();
TextEditingController _password = new TextEditingController();
bool loading;
final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>
();
#override
void initState() {
// TODO: implement initState
super.initState();
controller = new TabController(length: 2, vsync: this);
loading = false;
_email = new TextEditingController(text: "rajeshvishnani");
_password = new TextEditingController(text: "Rajesh#MaaKiRasoi");
}
#override
void dispose() {
// TODO: implement dispose
super.dispose();
controller.dispose();
setState(() {
loading = false;
});
_email.dispose();
_password.dispose();
}
final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
bool _autoValidate = false;
Future _writer(String username, String password, String token) async {
final storage = new FlutterSecureStorage();
await storage.write(key: authTokenKeys, value: token);
print(await storage.read(key: authTokenKeys));
await storage.write(key: nameKeys, value: username);
print(await storage.read(key: nameKeys));
await storage.write(key: passwordKeys, value: password);
}
static final String authTokenKeys = 'auth_token';
static final String nameKeys = 'username';
static final String passwordKeys = 'password';
_login(username, password) async {
setState(() {
loading = true;
});
var body = json.encode({
"username": username,
"password": password,
});
Map<String, String> headers = {
'Content-type': 'application/json',
'Accept': 'application/json',
};
await http
.post("${GlobalVar.Ip}/wp-json/jwt-auth/v1/token",
body: body, headers: headers)
.then((response) {
var body = json.decode(response.body);
if (response.statusCode == 200) {
// TODO: you need to store body['token'] to use in some authentication
loading = false;
_writer(_email.text, _password.text, body['token']);
Navigator.pushReplacement(context,
MaterialPageRoute(builder: (BuildContext ctx) => HomePage()));
} else {
// TODO: alert message
final snackBar = SnackBar(
content: Text(body['message']),
);
_scaffoldKey.currentState.showSnackBar(snackBar);
}
setState(() {
loading = false;
});
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
key: _scaffoldKey,
resizeToAvoidBottomPadding: false,
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('images/art.png'),
fit: BoxFit.fill,
colorFilter: ColorFilter.mode(
Colors.white12.withOpacity(0.2), BlendMode.dstATop),
),
),
child: ListView(
shrinkWrap: true,
physics: BouncingScrollPhysics(),
children: <Widget>[
SizedBox(
height: MediaQuery.of(context).size.height / 30,
),
Align(
alignment: Alignment.topCenter,
child: CircleAvatar(
backgroundColor: Colors.grey,
radius: 55.0,
backgroundImage: AssetImage('images/logo.png'),
),
),
SizedBox(
height: MediaQuery.of(context).size.height / 30,
),
Stack(
alignment: Alignment.center,
children: <Widget>[
SizedBox(
height: MediaQuery.of(context).size.height / 300,
child: new Center(
child: new Container(
height: 10.0,
color: Colors.black12,
),
),
),
Row(
children: <Widget>[
SizedBox(
width: MediaQuery.of(context).size.width / 4,
),
Chip(
label: Text(
"SIGN IN",
style: TextStyle(color: Colors.white, fontSize: 18.0),
),
backgroundColor: Color(0xFFD1A155),
),
SizedBox(
width: MediaQuery.of(context).size.width / 35,
child: Container(
width: MediaQuery.of(context).size.height / 12,
height: 2.0,
color: Colors.white,
),
),
Chip(
label: Text(
"SIGN UP",
style: TextStyle(color: Colors.white, fontSize: 18.0),
),
backgroundColor: Colors.black87,
),
],
)
],
),
SizedBox(
height: MediaQuery.of(context).size.height / 35,
),
Align(
alignment: Alignment.center,
child: Text(
"Welcome back!",
style: TextStyle(
fontSize: 20.0,
color: Color(0xFFD1A155),
),
)),
SizedBox(
height: MediaQuery.of(context).size.height / 30,
),
Form(
key: _formKey,
autovalidate: _autoValidate,
child: Column(
children: <Widget>[
Theme(
data: ThemeData(
hintColor: Colors.black26,
primaryColor: Color(0xFFD1A155),
),
child: Padding(
padding: const EdgeInsets.only(left: 15.0, right: 15.0),
child: TextFormField(
keyboardType: TextInputType.emailAddress,
//validator: _email.text.isEmpty?:null,
controller: _email,
decoration: InputDecoration(
border:
OutlineInputBorder(borderSide: BorderSide()),
prefixIcon: Icon(
Icons.email,
color: Color(0xFFD1A155),
),
hintText: 'Email Address',
hintStyle: TextStyle(
color: Colors.black,
fontWeight: FontWeight.w400)),
),
),
),
SizedBox(
height: MediaQuery.of(context).size.height / 45,
),
Theme(
data: ThemeData(
primaryColor: Color(0xFFD1A155),
hintColor: Colors.black26),
child: Padding(
padding: const EdgeInsets.only(left: 15.0, right: 15.0),
child: TextFormField(
keyboardType: TextInputType.text,
obscureText: true,
controller: _password,
decoration: InputDecoration(
border:
OutlineInputBorder(borderSide: BorderSide()),
prefixIcon: Icon(
Icons.lock,
color: Color(0xFFD1A155),
),
hintText: 'Password',
hintStyle: TextStyle(
color: Colors.black,
fontWeight: FontWeight.w400)),
),
),
),
Padding(
padding: const EdgeInsets.only(right: 15.0, left: 10.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
children: <Widget>[
ActionChip(
onPressed: () {},
avatar: Checkbox(
value: false,
onChanged: (bool z) {
print(z);
},
activeColor: Color(0xFFD1A155),
),
label: Text("Remember Me"),
backgroundColor: Colors.transparent,
),
],
),
Text(
"Forgot Password?",
style: TextStyle(
color: Color(0xFFD1A155),
),
),
],
),
),
Padding(
padding: const EdgeInsets.only(left: 15.0, right: 15.0),
child: InkWell(
onTap: () {
_login(_email.text, _password.text);
// Navigator.push(
// context,
// MaterialPageRoute(
// builder: (context) => HomePage()));
},
child: loading
? CircularProgressIndicator()
: Container(
height: MediaQuery.of(context).size.height / 13,
//width: MediaQuery.of(context).size.height / 1.8,
decoration: BoxDecoration(
color: Color(0xFFD1A155),
borderRadius: BorderRadius.circular(5.0),
),
child: Center(
child: Text(
"LOGIN",
style: TextStyle(
color: Colors.white, fontSize: 18.0),
),
),
),
),
)
],
),
),
SizedBox(
height: MediaQuery.of(context).size.height / 15,
),
Stack(
alignment: Alignment.center,
children: <Widget>[
SizedBox(
height: 2.0,
child: new Center(
child: new Container(
height: 10.0,
color: Colors.black12,
),
),
),
Container(
height: MediaQuery.of(context).size.height / 18,
width: MediaQuery.of(context).size.height / 11,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(23.0),
color: Colors.white,
border: Border.all(color: Colors.black12)),
child: Center(
child: Text(
"OR",
style: TextStyle(fontSize: 18.0),
)),
),
],
),
SizedBox(
height: MediaQuery.of(context).size.height / 30,
),
Padding(
padding: const EdgeInsets.only(left: 15.0, right: 15.0),
child: Row(
children: <Widget>[
Container(
height: MediaQuery.of(context).size.height / 13,
width: MediaQuery.of(context).size.width / 2.2,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(5.0),
color: Colors.white,
border: Border.all(color: Colors.black12)),
child: Row(
children: <Widget>[
SizedBox(
width: 18.0,
),
Icon(Icons.tag_faces),
SizedBox(
width: 10.0,
),
Text(
"Facebook",
style: TextStyle(fontSize: 22.0, color: Colors.blue),
),
],
),
),
SizedBox(
width: MediaQuery.of(context).size.width / 40,
),
Container(
height: MediaQuery.of(context).size.height / 13,
width: MediaQuery.of(context).size.width / 2.3,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(5.0),
color: Colors.white,
border: Border.all(color: Colors.black12)),
child: Row(
children: <Widget>[
SizedBox(
width: 18.0,
),
Icon(Icons.tag_faces),
SizedBox(
width: 10.0,
),
Text(
"Google+",
style: TextStyle(fontSize: 22.0, color: Colors.red),
),
],
),
),
],
),
),
SizedBox(
height: MediaQuery.of(context).size.height / 20,
),
Align(
alignment: Alignment.center,
child: InkWell(
onTap: () => Navigator.push(
context, MaterialPageRoute(builder: (context) => SignUp())),
child: RichText(
text: TextSpan(
text: "Don't have an account?",
style: TextStyle(fontSize: 20.0, color: Colors.black87),
children: <TextSpan>[
TextSpan(
text: ' Sign up',
style: TextStyle(
color: Color(0xFFD1A155),
fontWeight: FontWeight.bold)),
])),
),
),
SizedBox(
height: MediaQuery.of(context).size.height / 30,
),
],
),
),
);
}
}

Answer 1

I also have similar type of error, Be make sure that the argument of .decode method shouldn't be empty object. Instead of using this line:
var body = json.decode(response.body);
Try
if(response.body.isNotEmpty) {
json.decode(response.body);
}
Do try this, hope it will work for you.

Answer 2

Print your body and double check you aren't trying to decode an array rather than on object.

Answer 3

I had similar type of problem, i tried everything but eventually the problem was that I was using http intead of using https even though the apis was in https, i forgot to add s at in http.
After changing to https from http the error was gone.

Answer 4

check your backend it return null object in the response body