Develop Reference

AndroidStudio Login using REST servlet and oracle

I want to make Login Activity using eclipse servlet(REST file) and oracle.
I want to compare column value of EMAIL, PASS of table EMPLOYEES to EditText(user input email and password).
How can I compare two input Strings to column of database table?
This is LoginActivity file(MainActivity)
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.HashMap;
import java.util.Map;
public class MainActivity extends AppCompatActivity{
EditText email_txt, pw_txt;
Button login_btn;
String REST_URL = "http://localhost:8080/url";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
email_txt = (EditText)findViewById(R.id.email_txt);
pw_txt = (EditText)findViewById(R.id.pw_txt);
login_btn = (Button)findViewById(R.id.login_btn);
login_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String useremail = email_txt.getText().toString();
String userpass = pw_txt.getText().toString();
//I want to fill this below
//
}
});
}
#Override
public void onResume() {
super.onResume();
JSONClient toServer;
toServer = new JSONClient((JSONClient.MyCallbackInterface) this);
toServer.execute(REST_URL, "GET", "");
}
}
This is JSONClient(Activity)
public class JSONClient extends AsyncTask<String, Void, JSONObject> {
private MyCallbackInterface mCallback;
public JSONClient(MyCallbackInterface callback) {
mCallback = callback;
}
#Override
protected JSONObject doInBackground(String... params) {
String url = params[0];
String method = params[1];
String content = params[2];
return getJSONFromUrl(url, method, content);
}
#Override
protected void onPostExecute(JSONObject result) {
mCallback.onRequestComplete(result);
}
public interface MyCallbackInterface {
public void onRequestComplete(JSONObject result);
}
public JSONObject getJSONFromUrl(String urlStr, String method, String content) {
JSONObject jObj = new JSONObject();
try {
URL url = new URL(urlStr);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod(method);
urlConnection.setConnectTimeout(3000);
if (content != null && content.length() > 0) {
urlConnection.getOutputStream().write(content.getBytes(StandardCharsets.UTF_8));
}
String respStr = getStringFromInputStream(urlConnection.getInputStream());
Log.d("JSON Parser1", "Response from server: " + respStr);
jObj = new JSONObject(respStr);
} catch (Exception e) {
Log.e("JSON Parser Exception", e.getLocalizedMessage());
}
return jObj;
}
private String getStringFromInputStream(InputStream is) {
StringBuilder sb = new StringBuilder();
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(is));
try {
while ((line = br.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
Log.e("JSON Client", "Error while reading response from server");
return null;
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
Log.e("JSON Client", "Error while making string from HTTP response");
return null;
}
}
}
return sb.toString();
}
}

AsyncTask/doInBackground not executing

I'm trying to create an app that queries a site of cat images, saves them to the android device if the JSON ID is unique, and then display them from the device in a slideshow format. Despite everything my AsyncTask doesn't seem to actually be executing. Debugger confirms a network connection is established and doesn't feed me back any errors so I have no idea what's wrong with my code. Hoping someone can help! Code is below:
package com.example.lab2;
import androidx.appcompat.app.AppCompatActivity;
import androidx.loader.content.AsyncTaskLoader;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.Image;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.provider.MediaStore;
import android.util.Log;
import android.widget.ImageView;
import android.widget.ProgressBar;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.sql.Array;
import java.util.ArrayList;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
CatImages req = new CatImages();
req.execute();
}
class CatImages extends AsyncTask<String, Integer, String> {
ArrayList<String> ids = new ArrayList<String>();
ContextWrapper cw = new ContextWrapper(getApplicationContext());
Bitmap images;
String id;
ImageView imageView = findViewById(R.id.imageView);
ProgressBar progressBar = findViewById(R.id.progressBar);
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
boolean on = true;
#Override
protected String doInBackground(String... strings) {
while(on == true) {
try {
URL url = new URL("https://cataas.com/cat?json=true");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream response = urlConnection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(response, "UTF-8"), 8);
StringBuilder builder = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
builder.append(line + "\n");
}
String result = builder.toString();
JSONObject image = new JSONObject(result);
id = image.getString("id");
ids.add(id);
for (String element : ids) {
if (element.contains(id)) {
return null;
} else {
images = BitmapFactory.decodeStream(response);
File path = new File(directory, id + ".jpg");
FileOutputStream outputStream = new FileOutputStream(path);
images.compress(Bitmap.CompressFormat.PNG, 100, outputStream);
outputStream.flush();
outputStream.close();
ids.add(id);
}
}
for (int i = 0; i < 100; i++) {
try {
publishProgress(i);
Thread.sleep(30);
} catch (Exception e) {
e.printStackTrace();
}
}
} catch (IOException | JSONException e) {
return null;
}
}
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
for(String element : ids) {
if(element.contains(id)) {
File openedPic = new File(directory, id + ".jpg");
try {
Bitmap opener = BitmapFactory.decodeStream(new FileInputStream(openedPic));
imageView.setImageBitmap(opener);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
}
#Override
protected void onPostExecute(String fromDoInBackground) {
super.onPostExecute(fromDoInBackground);
}
}
}

Try changing !=null to ==null in your second while loop.
Also you just need while(on) in your first while loop.
Let me know if anything changes.

I would like to effect the TextView from the json data I get from httpurlconnection

//[(START)File:ThirdActivity.java] -->
package com.example.caleb.splash_screen;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.io.IOException;
import java.io.OutputStream;
public class ThirdActivity extends AppCompatActivity {
//public String text = "https://jsonparsingdemo-cec5b.firebaseapp.com/jsonData/moviesDemoItem.txt";
public TextView text;
private void writeStream(OutputStream out){
String output = "Hello world";
// out.write(output.getBytes());
//out.flush();
}
/*private String readStream(InputStream is) {
try {`enter code here`
ByteArrayOutputStream bo = new ByteArrayOutputStream();
int i = is.read();
while(i != -1) {
bo.write(i);
i = is.read();
}
return bo.toString();
} catch (IOException e) {
return "";
}
}*/
//[(START) readStream -->
private String readStream(InputStream in) throws IOException {
BufferedReader bin = new BufferedReader(new InputStreamReader(in));
//temporary
try {
StringBuilder sb = new StringBuilder();
String inputLine;
while ((inputLine = bin.readLine()) != null) {
sb.append(inputLine);
}
return sb.toString();
} finally {
}
}
//[(END) readStream -->
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_third2);
text = (TextView)findViewById(R.id.textView);
new JSONTask().execute("https://jsonparsingdemo-cec5b.firebaseapp.com/jsonData/moviesDemoItem.txt");
}
}
//[(END)File:ThirdActivity] -->
//[(START)File:JSONTask] -->
package com.example.caleb.splash_screen;
import android.app.Activity;
import android.content.Context;
import android.os.AsyncTask;
import android.support.v4.widget.TextViewCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
/**
* Created by Caleb on 12/17/2017.
*/
public class JSONTask extends AsyncTask<String,String,String> {
//final TextView txt = (TextView)findViewById(R.id.textView);
private Context context;
public JSONTask(Activity ThirdActivity) {
context = ThirdActivity;
}
#Override
protected String doInBackground(String... params) {
BufferedReader reader = null;
HttpURLConnection urlConnection = null;
//{(START)] Working Connection:ALERT! Error within code will cause crash -->
try {
URL url = new URL(params[0]);
Log.w("testing", "test");
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(false);
urlConnection.connect();
//urlConnection.setChunkedStreamingMode(0);
//OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
//writeStream(out);
/*int a = urlConnection.getResponseCode();
String b = String.valueOf(a);
Log.e(b, "yesssssssssssssssss");*/
InputStream in = urlConnection.getInputStream();
//InputStream in = new BufferedInputStream(urlConnection.getInputStream());
reader = new BufferedReader(new InputStreamReader(in));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
/*String data = readStream(in);
/*final TextView textView = (TextView) findViewById(R.id.textView);
textView.setText("hello");
*/
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
throw new RuntimeException(e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
//{(END)] Working Connection -->
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
TextView text = (TextView) ((AppCompatActivity) context).findViewById(R.id.textView);
text.setText(result);
}
}
//[(END)File:JSONTask] -->
/Desired Effect/
Blockquote
I would like to pull data from the json file that the url points to and change the TextView within the UI called textView. I don't understand how to access the findviewbyid within the AsyncTask. I've looked all throughout the internet and couldn't find anything :( Any suggestions are greatly appreciated!!

try weak reference to get textview in asynctask
//call async task
new JSONTask(yourTextView).execute();
//in your async task
private final WeakReference<TextView> textViewReference;
public JSONTask (TextView textView){
textViewReference = new WeakReference<TextView>( textView);
}
#Override
protected void onPostExecute() {
TextView textView = textViewReference.get();
//set values to text view
}

I'm using OkHttp to do the same task in my apps
HTTP/2 support allows all requests to the same host to share a socket.
Connection pooling reduces request latency (if HTTP/2 isn’t available).
Transparent GZIP shrinks download sizes.
Response caching avoids the network completely for repeat requests.
Add this dependency
implementation 'com.squareup.okhttp3:okhttp:3.9.1'
Then create/code a new Class named OkHttpHandler
class OkHttpHandler extends AsyncTask<String, String, String> {
OkHttpClient client = new OkHttpClient();
private volatile String data;
public String getResult() {
return data;
}
#Override
protected String doInBackground(String... params) {
try {
Request.Builder builder = new Request.Builder();
builder.url(params[0]);
Request request = builder.build();
Response response = client.newCall(request).execute();
return response.body().string();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
data = s;
}
}
}
and use it like this way
String str = new OkHttpHandler().execute("http://www.<TEST>.com/json").get();
I also suggest to check whether Wi-fi-Connected/Bluetooth-Connected or PhoneData-Enabled is false if true/else, Proceed to your code

Late-enabling -Xcheck:jni Android studio logs

I am trying to run a simple app that extracts html from a page and displays it in the logs.
Here is the Java code:
package com.example.khkr.jsondemo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public class DownloadTask extends AsyncTask<String,Void,String>
{
#Override
protected String doInBackground(String... params) {
URL url;
String result = "";
try {
url = new URL(params[0]);
HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
urlConnection.connect();
InputStream in = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(in);
int data = reader.read();
while (data!=-1)
{
char current = (char)data; result+=current;
data = reader.read();
}
return result;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONObject jsonObject = new JSONObject(result);
String weatherInfo = jsonObject.getString("weather");
Log.i("Weather content",weatherInfo);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
The problem is I don't see any errors in the code , but when I try to run the app, I get the following Logs which never make sense to me. Here are the logs:
https://gist.github.com/khkr/d96396ff6f8e34b3e9a430a805b735a7

I cant use list view in android with json more than one result

Hi every one I have a problem
i want to get data from site with json and show it in my android list view
but in my program i can only see the first result of json and dont
show me the all result of the json.
please help me.
this is my code
mainactivity code:
package com.example.delta.travel;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class MainActivity extends ListActivity {
private ProgressDialog pd;
JSONParser jParser=new JSONParser();
ArrayList<HashMap<String,String>> P;
JSONArray s=null;
private final String url="http://192.168.1.3/upload/travel.php";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
P = new ArrayList<>();
new travel().execute();
}
class travel extends AsyncTask<String,Void,String>{
#Override
protected void onPreExecute() {
super.onPreExecute();
pd=new ProgressDialog(MainActivity.this);
pd.setMessage("login");
pd.show();
}
#Override
protected String doInBackground(String... params) {
List<NameValuePair> parms=new ArrayList<>();
JSONObject json=jParser.makeHTTPRequest(url,"GET");
try {
int t=json.getInt("t");
if(t==1){
s=json.getJSONArray("travel");
for(int i=0;i<s.length();i++){
JSONObject c=s.getJSONObject(i);
String companyname=c.getString("companyname");
String cod=c.getString("cod");
String bign=c.getString("bign");
String stop=c.getString("stop");
String date=c.getString("date");
String time=c.getString("time");
String price=c.getString("price");
HashMap<String,String>map=new HashMap<String,String>();
map.put("companyname",companyname);
map.put("cod",cod);
map.put("bign",bign);
map.put("stop",stop);
map.put("date",date);
map.put("time",time);
map.put("price",price);
P.add(map);
}
}else {
Toast.makeText(MainActivity.this,"No Data Found",Toast.LENGTH_SHORT).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
pd.dismiss();
runOnUiThread(new Runnable() {
#Override
public void run() {
ListAdapter adapter = new SimpleAdapter(MainActivity.this, P, R.layout.item_list,
new String[]{"companyname", "cod", "bign", "stop", "date", "time", "price"},
new int[]{R.id.companyname, R.id.cod, R.id.bign, R.id.stop, R.id.date, R.id.time1, R.id.price});
setListAdapter(adapter);
}
});
}
}
}
and my json parser code:
package com.example.delta.travel;
import android.net.http.HttpResponseCache;
import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.util.Date;
import java.util.List;
/**
* Created by delta on 5/28/2016.
*/
public class JSONParser {
static InputStream is=null;
static JSONObject jObj=null;
static String json="";
// constructor
public JSONParser(){
}
// function get json from url
// by making HTTP POST or GET method
public JSONObject makeHTTPRequest(String urlString, String method) {
if(method.equals("POST")){
URL url = null;
try {
url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Accept", "application/json");
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
StringBuilder sb = new StringBuilder();
while ((output = br.readLine()) != null) {
sb.append(output);
}
conn.disconnect();
json = sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}else if(method.equals("GET")){
URL url = null;
try {
url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/json");
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
StringBuilder sb = new StringBuilder();
while ((output = br.readLine()) != null) {
sb.append(output);
}
conn.disconnect();
json = sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
e.printStackTrace();
}
return jObj;
}
}
and my php code:
<?php
$con=mysqli_connect("localhost","root","","travels");
mysqli_set_charset($con,"utf8");
$response=array();
$result=mysqli_query($con,"select * from travel");
if(mysqli_num_rows($result)>0){
while($row=mysqli_fetch_array($result)){
$temp=array();
$temp["companyname"]=$row["companyname"];
$temp["cod"]=$row["cod"];
$temp["bign"]=$row["bign"];
$temp["stop"]=$row["stop"];
$temp["date"]=$row["date"];
$temp["time"]=$row["time"];
$temp["price"]=$row["price"];
$response["travel"]=array();
array_push($response["travel"],$temp);
$response["t"]=1;
echo json_encode($response);
}
}
else{
$response["t"]=0;
$response["message"]="Not Found";
echo json_encode($response);
}
?>