Database Develop

Please help with Java homework!!!

Okay here's the thing:
I have an assignment in Java class that's due in 1.5 hours and figured that this would be the best place to ask since you guys are (hopefully) good at this kind of stuff.
Here's the code:
/**
* Exercise 3.
*
* Complete the setBalances method below to set all accounts in an array to the specified value.
*
* The test methods should pass.
*
*/
public class AccountMethods {
public static void main(String[] args) {
Account[] accounts = {new Account(100, "joe"),
new Account(200, "jane"),
new Account(300, "jerry")};
testSetBalances(accounts, 50);
testBalanceNonNegative();
}
public static void setBalances(Account[] accounts, double value) {
double balance = 0;
for (int i = 0; i < accounts.length; i++) {
balance += accounts.getBalance();
}
}
public static boolean testSetBalances(Account[] accounts, double value) {
setBalances(accounts, value);
for (int i = 0; i < accounts.length; i++) {
if (accounts.getBalance() != value) {
System.out.println("testSetBalances fails on element " + i);
return false;
}
}
System.out.println("testSetBalances passes.");
return true;
}
public static boolean testBalanceNonNegative() {
Account a = new Account(100, "jim");
a.setBalance(-100);
if (a.getBalance() < 0) {
System.out.println("testBalanceNonNegtaive fails");
return false;
} else {
System.out.println("testBalanceNonNegative passes.");
return true;
}
}
}
The bold part is what I'm suppose to be working with, but I can't get it to pass in the testSetBalances method. I don't know if I'm explaining this right, but when I'm compiling the code, it's suppose to say:
testSetBalances passes
But instead, it's saying: testSetBalances fails on element 0
Don't worry about the other parts of the code because the assignment for that is done already.

[Q] Get active Wifi connection information

Hello everyone,
I am making an app for android, in this I need to know some data of the active wifi connection, such as network type and encryption used, as shown in the image.
Information as if WEP, WPA, WPA2 and TKIP or AES encryption
I tried with android.net.wifi and within wificonfiguration classes and their different methods, they return me a set of information, but is not always valid, however as shown by the android itself in the properties of the connection if is true forever.
Thank you very much.
Att,
Cristhian Angarita
Colombia, Bogota

Most probably you have already found answer: currentWifi.getSSID() is quoted in most cases where scanResult.SSID is not (and of course you must not use == on strings ).
Try something like this, it returns current SSID or null:
Code:
public static String getCurrentSsid(Context context) {
String ssid = null;
ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (networkInfo.isConnected()) {
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final WifiInfo connectionInfo = wifiManager.getConnectionInfo();
if (connectionInfo != null && !StringUtil.isBlank(connectionInfo.getSSID())) {
ssid = connectionInfo.getSSID();
}
}
return ssid;
}
also permissions are required:
Code:
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
StringUtil is not a standard Android class, so you can use TextUtils instead. The code then looks like this:
Code:
public static String getCurrentSsid(Context context) {
String ssid = null;
ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (networkInfo.isConnected()) {
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final WifiInfo connectionInfo = wifiManager.getConnectionInfo();
if (connectionInfo != null && !TextUtils.isEmpty(connectionInfo.getSSID())) {
ssid = connectionInfo.getSSID();
}
}
return ssid;
}
bye

Black screen and app shutdown when trying to go back to the previous activity/view

When i run my script below everything works fine. When i want to go back to the previous activity i get a black screen on the emulator and then the app shuts down, i also get a black screen when i exit the application and try to resume it.
The script:
Code:
package com.example.bono.as3;
import android.app.Activity;
import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.io.IOException;
import java.io.InputStream;
public class Main extends Activity {
DrawView drawView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
drawView = new DrawView(this);
setContentView(drawView);
}
@Override public void onResume(){
super.onResume();
drawView.resume();
}
@Override public void onPause(){
super.onPause();
drawView.pause();
}
public class DrawView extends SurfaceView implements Runnable{
Thread gameloop = new Thread();
SurfaceHolder surface;
volatile boolean running = false;
AssetManager assets = null;
BitmapFactory.Options options = null;
Bitmap incect[];
int frame = 0;
public DrawView(Context context){
super(context);
surface = getHolder();
assets = context.getAssets();
options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
incect = new Bitmap[2];
try {
for (int n = 0; n < incect.length; n++){
String filename = "incect"+Integer.toString(n+1)+".png";
InputStream istream = assets.open(filename);
incect[n] = BitmapFactory.decodeStream(istream,null,options);
istream.close();
}
} catch (IOException e){
e.printStackTrace();
}
}
public void resume(){
running = true;
gameloop = new Thread(this);
gameloop.start();
}
public void pause(){
running = false;
while (true){
try {
gameloop.join();
}
catch (InterruptedException e){}
}
}
@Override public void run (){
while (running){
if (!surface.getSurface().isValid())
continue;
Canvas canvas = surface.lockCanvas();
canvas.drawColor(Color.rgb(85, 107, 47));
canvas.drawBitmap(incect[frame], 0, 0, null);
surface.unlockCanvasAndPost(canvas);
frame++;
if (frame > 1) frame = 0;
try {
Thread.sleep(500);
} catch (InterruptedException e){
e.printStackTrace();
}
}
}
}
}
I dont get any error message in the log, what i do get is about 13 messages saying "suspending all threads took: X ms" so it has something to the with my gameloop Thread i think. Unfortunately i dont see what the problem is in my code... Can anyone help me with this?

Google Maps API v2 tutorials wanted.

Hi everyone,
I'm working on my first app (still a noob) with Google Maps API v2 in Android Studio and followed a couple of tutorials to get the user's current position and draw a path between two points (not working right now). I am using Retrofit to parse JSON. Now I have a current position and when the user taps the screen, a green marker appears and when the user taps again a red marker appears. Clicking on my driving button to get the route between red and green does nothing.
I would like the current position of the user also to be the starting point (so no extra markers). A user has to be able to enter an address and a new marker has to be set at that address. A route should be drawn between the current position of the user and the new address (showing distance and time) Like Runkeeper, I would like that - when the user moves - the marker at the current position moves with him.
I just can't find any good up to date tutorials which I can use to create this? Is someone able to help me or could someone look at my code? Or know any good tutorials?
Code:
package com.lemonkicks.trackmycab.trackmycab;
import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.location.Location;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.lemonkicks.trackmycab.trackmycab.POJO.Example;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import java.util.ArrayList;
import java.util.List;
import retrofit.Call;
import retrofit.Callback;
import retrofit.GsonConverterFactory;
import retrofit.Response;
import retrofit.Retrofit;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener {
private GoogleMap mMap;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
Marker mCurrLocationMarker;
LocationRequest mLocationRequest;
LatLng origin;
LatLng dest;
ArrayList<LatLng> MarkerPoints;
TextView ShowDistanceDuration;
Polyline line;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
ShowDistanceDuration = (TextView) findViewById(R.id.show_distance_time);
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkLocationPermission();
}
// Initializing
MarkerPoints = new ArrayList<>();
//show error dialog if Google Play Services not available
if (!isGooglePlayServicesAvailable()) {
Log.d("onCreate", "Google Play Services not available. Ending Test case.");
finish();
} else {
Log.d("onCreate", "Google Play Services available. Continuing.");
}
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Setting onclick event listener for the map
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
// clearing map and generating new marker points if user clicks on map more than two times
if (MarkerPoints.size() > 1) {
mMap.clear();
MarkerPoints.clear();
MarkerPoints = new ArrayList<>();
ShowDistanceDuration.setText("");
}
// Adding new item to the ArrayList
MarkerPoints.add(point);
Log.i("onMapClick", "Map clicked, number of points is now " + MarkerPoints.size());
// Creating MarkerOptions
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(point);
/**
* For the start location, the color of marker is GREEN and
* for the end location, the color of marker is RED.
*/
if (MarkerPoints.size() == 1) {
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
} else if (MarkerPoints.size() == 2) {
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
// Add new marker to the Google Map Android API V2
mMap.addMarker(options);
// Checks, whether start and end locations are captured
if (MarkerPoints.size() >= 2) {
origin = MarkerPoints.get(0);
dest = MarkerPoints.get(1);
Log.i("onMapClick", "origin and dest now set.");
} else {
Log.i("onMapClick", "origin and dest not set as number of marker points is " + MarkerPoints.size());
}
}
});
Button btnDriving = (Button) findViewById(R.id.btnDriving);
btnDriving.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
build_retrofit_and_get_response("driving");
}
});
Button btnWalk = (Button) findViewById(R.id.btnWalk);
btnWalk.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
build_retrofit_and_get_response("walking");
}
});
//Initialize Google Play Services
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
} else {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
@Override
public void onConnected(Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(1000);
mLocationRequest.setFastestInterval(1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
if (mCurrLocationMarker != null) {
mCurrLocationMarker.remove();
}
//Place current location marker
LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("Current Position");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
mCurrLocationMarker = mMap.addMarker(markerOptions);
//move map camera
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
//stop location updates
if (mGoogleApiClient != null) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
private void build_retrofit_and_get_response(String type) {
String url = "https://maps.googleapis.com/maps/";
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
RetrofitMaps service = retrofit.create(RetrofitMaps.class);
Call<Example> call = service.getDistanceDuration("metric", origin.latitude + "," + origin.longitude,dest.latitude + "," + dest.longitude, type);
call.enqueue(new Callback<Example>() {
@Override
public void onResponse(Response<Example> response, Retrofit retrofit) {
try {
//Remove previous line from map
if (line != null) {
line.remove();
}
// This loop will go through all the results and add marker on each location.
for (int i = 0; i < response.body().getRoutes().size(); i++) {
String distance = response.body().getRoutes().get(i).getLegs().get(i).getDistance().getText();
String time = response.body().getRoutes().get(i).getLegs().get(i).getDuration().getText();
ShowDistanceDuration.setText("Distance:" + distance + ", Duration:" + time);
String encodedString = response.body().getRoutes().get(0).getOverviewPolyline().getPoints();
List<LatLng> list = decodePoly(encodedString);
line = mMap.addPolyline(new PolylineOptions()
.addAll(list)
.width(20)
.color(Color.RED)
.geodesic(true)
);
}
} catch (Exception e) {
Log.d("onResponse", "There is an error");
e.printStackTrace();
}
}
@Override
public void onFailure(Throwable t) {
Log.d("onFailure", t.toString());
}
});
}
private List<LatLng> decodePoly(String encoded) {
List<LatLng> poly = new ArrayList<LatLng>();
int index = 0, len = encoded.length();
int lat = 0, lng = 0;
while (index < len) {
int b, shift = 0, result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
LatLng p = new LatLng( (((double) lat / 1E5)),
(((double) lng / 1E5) ));
poly.add(p);
}
return poly;
}
// Checking if Google Play Services Available or not
private boolean isGooglePlayServicesAvailable() {
GoogleApiAvailability googleAPI = GoogleApiAvailability.getInstance();
int result = googleAPI.isGooglePlayServicesAvailable(this);
if(result != ConnectionResult.SUCCESS) {
if(googleAPI.isUserResolvableError(result)) {
googleAPI.getErrorDialog(this, result,
0).show();
}
return false;
}
return true;
}
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
public boolean checkLocationPermission(){
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Asking user if explanation is needed
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
}

Listview filtering and getting right onclickitem

I need help for filtering a listview and open a new activity from the filtered list view onItemClick. The problem is I get the filtered view right but I do not know how to store the ID from JSON for each post.
Problem I am facing: When I click the list item when it is not yet filtered it passes the correct ID for the selected list item. But when I try to filter it, it is showing wrong data (data of another item) in the next activity.
What I am trying to achieve: to show a list of titles in a listview which can be filtered with an edit text box. when I click on any list item (if it is filtered or not) it will pass the ID of that respective item to the next activity.
The Main Fragment - From where I am fetching JSON data and listing it in a listview and filtering the data with edit text.
Code:
public class EnglishHomeSearchFragment extends Fragment {
String url = "MYJSONURL/posts?categories=4&fields=id,title";
List list;
Gson gson;
ProgressBar progressBar;
ListView postList;
Map < String, Object > mapPost;
Map < String, Object > mapTitle;
int postID;
String postTitle[];
EditText editText;
private ArrayAdapter adapter;
private View rootView;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.search_englishhome, container, false);
if (!isConnected(getActivity())) buildDialog(getActivity()).show();
else {
postList = (ListView) rootView.findViewById(R.id.postList);
progressBar = (ProgressBar) rootView.findViewById(R.id.progressBar);
progressBar.setVisibility(View.VISIBLE);
initlist();
editText = (EditText) rootView.findViewById(R.id.inputsearchenglishhome);
editText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence cs, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
System.out.println("Text[" + s + "]");
adapter.getFilter().filter(s.toString());
}
@Override
public void afterTextChanged(Editable s) {
}
});
}
return rootView;
}
private void initlist() {
StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener < String > () {
@Override
public void onResponse(String s) {
gson = new Gson();
list = (List) gson.fromJson(s, List.class);
postTitle = new String[list.size()];
for (int i = 0; i < list.size(); ++i) {
mapPost = (Map < String, Object > ) list.get(i);
mapTitle = (Map < String, Object > ) mapPost.get("title");
postTitle[i] = (String) mapTitle.get("rendered");
}
adapter = new ArrayAdapter < > (Objects.requireNonNull(getActivity()), android.R.layout.simple_list_item_1, postTitle);
postList.setAdapter(adapter);
progressBar.setVisibility(View.GONE);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
Toast.makeText(getActivity(), "Error! Check your Internet Connection.", Toast.LENGTH_LONG).show();
}
});
RequestQueue rQueue = Volley.newRequestQueue(rootView.getContext());
rQueue.add(request);
postList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView << ? > parent, View view, int position, long id) {
mapPost = (Map < String, Object > ) list.get(position);
postID = ((Double) mapPost.get("id")).intValue();
Intent intent = new Intent(getActivity(), EnglishPost.class);
intent.putExtra("id", "" + postID);
startActivity(intent);
}
});
}
public boolean isConnected(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netinfo = Objects.requireNonNull(cm).getActiveNetworkInfo();
if (netinfo != null && netinfo.isConnectedOrConnecting()) {
android.net.NetworkInfo wifi = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
android.net.NetworkInfo mobile = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
return (mobile != null && mobile.isConnectedOrConnecting()) || (wifi != null && wifi.isConnectedOrConnecting());
} else return false;
}
public AlertDialog.Builder buildDialog(Context c) {
AlertDialog.Builder builder = new AlertDialog.Builder(c);
builder.setTitle("No Internet connection.");
builder.setMessage("You are not connected to the Internet.");
builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
return builder;
}
}
I have asked for help in several help forums. But no one helped me yet. I am new to Android app development. Please help me to resolve this issue without changing the whole code. Thank you in advance.
My JSON data looks like this:
Code:
[
{
id: 543,
title: {
rendered: "We are chopped down"
}
},
{
id: 535,
title: {
rendered: "Recover"
}
},
{
id: 528,
title: {
rendered: "Teacher said : Explain the law of gravitation."
}
},
{
id: 517,
title: {
rendered: "Person who ordered Swami to dress up and go to school __________?"
}
},
{
id: 514,
title: {
rendered: "Time when Swami complained of a headache _________?"
}
},
{
id: 512,
title: {
rendered: "When Swami ought to have been in the school prayer hall, he was lying on the?"
}
},
{
id: 510,
title: {
rendered: "Put out"
}
},
{
id: 505,
title: {
rendered: "Make out"
}
},
{
id: 502,
title: {
rendered: "Why did not Swami go to School?"
}
},
{
id: 484,
title: {
rendered: "With a shudder Swami realized that it was?"
}
}
]