[Android] JSon trong Android – Part 4: Handling retrieve JSON in Java
Your reveal, Provision for it will be the last part in the series JSon trong Android. We will write notes java code handling and most importantly, we have taken the JSON output from the previous section.
Content
Update: 21/08/2015 – Optimized code.
Our java structure includes the following files (Due to its relatively small number of files no classified into the package).
Writing class configuration, prepare
Say it a little confusing, but actually this. We need some constants to save some certain values and it is in class Where. For easy manipulation with objects “ex-lover” then we need to have a class Lover. And to retrieve JSON down, we need working class that LoadJson.
Construction constants
package cachhoc.net.demojson;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.widget.Toast;
public class Var {
// const for load and put data with server
public static final String KEY_METHOD = "method";
public static final String KEY_NICK = "nick";
public static final String KEY_PASS = "pass";
public static final String KEY_ID = "id";
public static final String KEY_NAME = "name";
public static final String KEY_PHONE = "phone";
public static final String KEY_BEGIN_DATE = "begin_date";
public static final String KEY_END_DATE = "end_date";
public static final String KEY_LOGIN = "login";
public static final String KEY_REGISTER = "register";
public static final String KEY_ADD = "add";
public static final int METHOD_LOGIN = 1;
public static final int METHOD_REGISTER = 2;
public static final int METHOD_GET_OLD_LOVER = 3;
public static final int METHOD_ADD_OLD_LOVER = 4;
public static void showToast(Context context, String sms) {
Toast.makeText(context, sms, Toast.LENGTH_SHORT).show();
}
// method for save and get nick and pass user
public static void save(Context context, String key, String value) {
SharedPreferences.Editor editor = PreferenceManager
.getDefaultSharedPreferences(context.getApplicationContext())
.edit();
editor.putString(key, value);
editor.apply();
}
public static String get(Context context, String key) {
SharedPreferences settings = PreferenceManager
.getDefaultSharedPreferences(context.getApplicationContext());
return settings.getString(key, null);
}
}
Nothing is confusing, in his classes just note that we use SharedPreferences to store nick and password when the user wants to remember to login later. And it is also often used to store settings (setting) applications.
Construction class Lover
Lover of us will have 5 School is id, name, phone, begin date (start date love) và end date (Day parting).
package cachhoc.net.demojson;
import org.json.JSONException;
import org.json.JSONObject;
public class Lover {
private int id;
private String name;
private String phone;
private String beginDate;
private String endDate;
public Lover() {
}
public Lover(int id, String name, String phone, String beginDate, String endDate) {
this.id = id;
this.name = name;
this.phone = phone;
this.beginDate = beginDate;
this.endDate = endDate;
}
public int getId() {
return id;
}
public Lover setId(int id) {
this.id = id;
return this;
}
public String getName() {
return name;
}
public Lover setName(String name) {
this.name = name;
return this;
}
public String getPhone() {
return phone;
}
public Lover setPhone(String phone) {
this.phone = phone;
return this;
}
public String getBeginDate() {
return beginDate;
}
public Lover setBeginDate(String beginDate) {
this.beginDate = beginDate;
return this;
}
public String getEndDate() {
return endDate;
}
public Lover setEndDate(String endDate) {
this.endDate = endDate;
return this;
}
public String toJSON() {
JSONObject jsonObject = new JSONObject();
try {
jsonObject.put(Var.KEY_ID, getId());
jsonObject.put(Var.KEY_NAME, getName());
jsonObject.put(Var.KEY_PHONE, getPhone());
jsonObject.put(Var.KEY_BEGIN_DATE, getBeginDate());
jsonObject.put(Var.KEY_END_DATE, getEndDate());
return jsonObject.toString();
} catch (JSONException e) {
e.printStackTrace();
return "";
}
}
}
Your attention getter usually we do not pay for anything and usually value public void… but I wrote it returns the object Lover (return this). This gives us easier manipulation. For example when you want to set 2 name and phone value, then you must write 2 lover.setPhone lover.setName times and the like can make the machine run more slowly when you go to the market like, you buy vegetables and run on, then run out buy beans,… And I'll just lover.setName(…).setPhone(…) ie shopping for vegetables and buy always the beans. =))
Method toJSON I wrote to Transfer 1 object into JSON format for ease of data manipulation sent to the server, however in this App, I do not use it, write so that you know and can be used for other apps only.
Construction class LoadJSon
Actually in not only taken but also send JSON data on up to handle more. And as the day before construction file lover.php I have said that we distinguish acts through the variable method.
package cachhoc.net.demojson;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
import org.apache.http.Header;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class LoadJson {
public static final String LINK = "https://cachhoc.net/mobile/demo-json/lover.php";
public void sendDataToServer(int method, HashMap<String, String> map) {
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
// put data to server
params.put(Var.KEY_METHOD, method);
if (map != null) {
for (String key : map.keySet()) {
params.put(key, map.get(key));
}
}
System.out.println("Post...");
client.post(LINK, params, new AsyncHttpResponseHandler() {
@SuppressWarnings("deprecation")
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
String json = new String(responseBody);
System.out.println("onSuccess:" + json);
onFinishLoadJSonListener.finishLoadJSon(null, json);
}
@SuppressWarnings("deprecation")
@Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
System.out.println("onFailure:" + statusCode);
String e;
if (statusCode == 404) {
e = "Requested resource not found";
} else if (statusCode == 500) {
e = "Something went wrong at server end";
} else {
e = "Device might not be connected to Internet";
}
onFinishLoadJSonListener.finishLoadJSon(e, null);
}
});
}
public static Lover jsonToLover(JSONObject jsonObject) {
try {
int id = jsonObject.getInt(Var.KEY_ID);
String name = jsonObject.getString(Var.KEY_NAME);
String phone = jsonObject.getString(Var.KEY_PHONE);
String beginDate = jsonObject.getString(Var.KEY_BEGIN_DATE);
String endDate = jsonObject.getString(Var.KEY_END_DATE);
return new Lover(id, name, phone, beginDate, endDate);
} catch (JSONException e) {
e.printStackTrace();
return null;
}
}
public static ArrayList<Lover> jsonToListLover(String json) {
ArrayList<Lover> list = new ArrayList<>();
try {
JSONArray arraySMSJson = new JSONArray(json);
for (int i = 0; i < arraySMSJson.length(); i++) {
JSONObject jsonObject = arraySMSJson.getJSONObject(i);
Lover lover = jsonToLover(jsonObject);
if (lover != null) {
list.add(lover);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return list;
}
public interface OnFinishLoadJSonListener {
void finishLoadJSon(String error, String json);
}
public OnFinishLoadJSonListener onFinishLoadJSonListener;
public void setOnFinishLoadJSonListener(OnFinishLoadJSonListener onFinishLoadJSonListener) {
this.onFinishLoadJSonListener = onFinishLoadJSonListener;
}
}
In that:
- Constant LINK is the path to the output file JSON – lover.php file already built eve.
-
Method sendDataToServer have 2 argument is the method to distinguish the action (login, register, load json, add lover) lover.php file on the server to distinguish treatment. Variable HashMap<String, String> map is a list of key-value pairs for the data we gave up, on the server will be based on the key to retrieve the corresponding value.
-
When we called client.post() the system will perform background to send data to the server. When finished, the system will automatically call the method onSuccess (success) or onFailure (helpful) and returns the corresponding value. In method onSuccess then responseBody is .json we get about, it will need a byte and move into a string.
-
To get JSON and serve other class processor, we build an interface that OnFinishLoadJSonListener modalities finishLoadJSon(String error, String json) to the other class implements JSON or error taken subsequent to treatment.
-
In this also comes built into your 2 method jsonToLover and jsonToListLover to convert the string json object or list Lover Lover.
Come hear and somewhat long-term. The most important part is to get the JSON has glitches. We continue handling 4 Activity.
Handling of Activity
Similar to the interface section, we will go to turn the steps:
Configuration, Chuẩn bị -> Login -> Register -> List Old Lover -> Add Lover
And in his code name the method also quite clear that it will not need much explanation.
Activity Login
To log in, then we will have to send the nick and pass up system check, lover.php file will check and if true, the new log in.
package cachhoc.net.demojson;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
public class LoginActivity extends AppCompatActivity implements View.OnClickListener, LoadJson.OnFinishLoadJSonListener {
private EditText editNick, editPass;
private CheckBox cbRememberPass;
private LoadJson loadJson;
private Context context;
private ProgressDialog progressDialog;
private String nick, pass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
context = this;
setupToolbar();
connectView();
loadJson = new LoadJson();
loadJson.setOnFinishLoadJSonListener(this);
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(context.getResources().getString(R.string.wait));
}
private void setupToolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setTitle(R.string.login);
}
}
}
private void connectView() {
editNick = (EditText) findViewById(R.id.edit_nick);
editPass = (EditText) findViewById(R.id.edit_pass);
cbRememberPass = (CheckBox) findViewById(R.id.cb_remember);
findViewById(R.id.btn_login).setOnClickListener(this);
findViewById(R.id.btn_register).setOnClickListener(this);
// get nick and pass if it be remember
nick = Var.get(context, Var.KEY_NICK);
pass = Var.get(context, Var.KEY_PASS);
if (nick != null && pass != null) {
editNick.setText(nick);
editPass.setText(pass);
cbRememberPass.setChecked(true);
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_login:
login();
break;
case R.id.btn_register:
register();
break;
default:
break;
}
}
private void register() {
Intent intent = new Intent(context, RegisterActivity.class);
startActivity(intent);
}
private void login() {
nick = editNick.getText().toString().trim();
pass = editPass.getText().toString().trim();
// not enter nick name
if (nick.length() == 0) {
editNick.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_nick));
return;
}
// not enter pass
if (pass.length() == 0) {
editPass.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_pass));
return;
}
// save nick and pass
if (cbRememberPass.isChecked()) {
Var.save(context, Var.KEY_NICK, nick);
Var.save(context, Var.KEY_PASS, pass);
} else {
Var.save(context, Var.KEY_NICK, null);
Var.save(context, Var.KEY_PASS, null);
}
HashMap<String, String> map = new HashMap<>();
map.put(Var.KEY_NICK, nick);
map.put(Var.KEY_PASS, pass);
loadJson.sendDataToServer(Var.METHOD_LOGIN, map);
progressDialog.show();
}
@Override
public void finishLoadJSon(String error, String json) {
if (progressDialog.isShowing()) {
progressDialog.hide();
}
try {
if (json != null) {
JSONObject jsonObject = new JSONObject(json);
if (jsonObject.getBoolean(Var.KEY_LOGIN)) {
Var.showToast(context, context.getResources().getString(R.string.login_success));
Intent intent = new Intent(context, MainActivity.class);
intent.putExtra(Var.KEY_NICK, nick);
startActivity(intent);
finish();
} else {
Var.showToast(context, context.getResources().getString(R.string.login_fail));
}
} else {
Var.showToast(context, error);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Activity Register
If no account, we need to register in order to add to the database system.
package cachhoc.net.demojson;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.EditText;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
public class RegisterActivity extends AppCompatActivity implements View.OnClickListener, LoadJson.OnFinishLoadJSonListener {
private EditText editNick, editPass, editRePass;
private LoadJson loadJson;
private Context context;
private ProgressDialog progressDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
context = this;
setupToolbar();
connectView();
loadJson = new LoadJson();
loadJson.setOnFinishLoadJSonListener(this);
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(context.getResources().getString(R.string.wait));
}
private void setupToolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setTitle(R.string.register);
}
}
}
private void connectView() {
editNick = (EditText) findViewById(R.id.edit_nick);
editPass = (EditText) findViewById(R.id.edit_pass);
editRePass = (EditText) findViewById(R.id.edit_re_pass);
findViewById(R.id.btn_reset).setOnClickListener(this);
findViewById(R.id.btn_register).setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_reset:
reset();
break;
case R.id.btn_register:
register();
break;
default:
break;
}
}
private void reset() {
editNick.setText("");
editPass.setText("");
editRePass.setText("");
editNick.requestFocus();
}
private void register() {
String nick = editNick.getText().toString().trim();
String pass = editPass.getText().toString().trim();
String repass = editRePass.getText().toString().trim();
// not enter nick name
if (nick.length() == 0) {
editNick.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_nick));
return;
}
// not enter pass
if (pass.length() == 0) {
editPass.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_pass));
return;
}
// not enter pass
if (repass.length() == 0) {
editRePass.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_repass));
return;
}
if (!repass.equals(pass)) {
editPass.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.pass_not_match));
return;
}
HashMap<String, String> map = new HashMap<>();
map.put(Var.KEY_NICK, nick);
map.put(Var.KEY_PASS, pass);
loadJson.sendDataToServer(Var.METHOD_REGISTER, map);
progressDialog.show();
}
@Override
public void finishLoadJSon(String error, String json) {
if (progressDialog.isShowing()) {
progressDialog.hide();
}
try {
if (json != null) {
JSONObject jsonObject = new JSONObject(json);
if (jsonObject.getBoolean(Var.KEY_REGISTER)) {
Var.showToast(context, context.getResources().getString(R.string.register_success));
finish();
} else {
Var.showToast(context, context.getResources().getString(R.string.register_fail));
}
} else {
Var.showToast(context, error);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Activity Add Lover
package cachhoc.net.demojson;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import com.wdullaer.materialdatetimepicker.date.DatePickerDialog;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.Calendar;
import java.util.HashMap;
public class AddLoverActivity extends AppCompatActivity implements View.OnClickListener, LoadJson.OnFinishLoadJSonListener, DatePickerDialog.OnDateSetListener {
private EditText editName, editPhone;
private Button btnBeginDate, btnEndDate;
private LoadJson loadJson;
private Context context;
private ProgressDialog progressDialog;
private String nick;
// for begin date or end date
private int typeDate;
private String beginDate = "", endDate = "";
public static final int BEGIN_DATE = 0;
public static final int END_DATE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_lover);
context = this;
setupToolbar();
connectView();
loadJson = new LoadJson();
loadJson.setOnFinishLoadJSonListener(this);
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(context.getResources().getString(R.string.wait));
nick = getIntent().getStringExtra(Var.KEY_NICK);
}
private void setupToolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setTitle(R.string.title_activity_add_lover);
}
}
}
private void connectView() {
editName = (EditText) findViewById(R.id.edit_name);
editPhone = (EditText) findViewById(R.id.edit_phone);
btnBeginDate = (Button) findViewById(R.id.btn_begin_date);
btnEndDate = (Button) findViewById(R.id.btn_end_date);
btnBeginDate.setOnClickListener(this);
btnEndDate.setOnClickListener(this);
findViewById(R.id.btn_add).setOnClickListener(this);
findViewById(R.id.btn_reset).setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_reset:
reset();
break;
case R.id.btn_add:
add();
break;
case R.id.btn_begin_date:
typeDate = BEGIN_DATE;
showDatePicker();
break;
case R.id.btn_end_date:
typeDate = END_DATE;
showDatePicker();
break;
default:
break;
}
}
private void showDatePicker() {
Calendar now = Calendar.getInstance();
DatePickerDialog dpd = DatePickerDialog.newInstance(
this,
now.get(Calendar.YEAR),
now.get(Calendar.MONTH),
now.get(Calendar.DAY_OF_MONTH)
);
String title;
if (typeDate == BEGIN_DATE) {
title = context.getResources().getString(R.string.begin_date);
} else {
title = context.getResources().getString(R.string.end_date);
}
dpd.show(getFragmentManager(), title);
}
@Override
public void onDateSet(DatePickerDialog view, int year, int monthOfYear, int dayOfMonth) {
String date = dayOfMonth + "/" + monthOfYear + "/" + year;
if (typeDate == BEGIN_DATE) {
beginDate = date;
btnBeginDate.setText(date);
} else {
endDate = date;
btnEndDate.setText(date);
}
}
private void reset() {
editName.setText("");
editPhone.setText("");
editName.requestFocus();
}
private void add() {
String name = editName.getText().toString().trim();
String phone = editPhone.getText().toString().trim();
// not enter nick name
if (name.length() == 0) {
editName.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_nick));
return;
}
// not enter pass
if (phone.length() == 0) {
editPhone.requestFocus();
Var.showToast(context, context.getResources().getString(R.string.enter_pass));
return;
}
HashMap<String, String> map = new HashMap<>();
map.put(Var.KEY_NICK, nick);
map.put(Var.KEY_NAME, name);
map.put(Var.KEY_PHONE, phone);
map.put(Var.KEY_BEGIN_DATE, beginDate);
map.put(Var.KEY_END_DATE, endDate);
loadJson.sendDataToServer(Var.METHOD_ADD_OLD_LOVER, map);
progressDialog.show();
}
@Override
public void finishLoadJSon(String error, String json) {
if (progressDialog.isShowing()) {
progressDialog.hide();
}
try {
if (json != null) {
JSONObject jsonObject = new JSONObject(json);
if (jsonObject.getBoolean(Var.KEY_ADD)) {
Var.showToast(context, context.getResources().getString(R.string.add_success));
finish();
} else {
Var.showToast(context, context.getResources().getString(R.string.add_fail));
}
} else {
Var.showToast(context, error);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Activity Main – List Lover
In this 2 part we need to handle the list and the list Adapter.
File MainActivity.java
package cachhoc.net.demojson;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity implements View.OnClickListener, LoadJson.OnFinishLoadJSonListener {
private ItemAdapter adapter;
private ArrayList<Lover> list;
private LoadJson loadJson;
private Context context;
private ProgressBar progressBar;
private ViewGroup layoutProgress;
private TextView tvNotify;
private String nick;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
loadJson = new LoadJson();
loadJson.setOnFinishLoadJSonListener(this);
setupToolbar();
setupRecyclerView();
findViewById(R.id.fab_add).setOnClickListener(this);
layoutProgress = (ViewGroup) findViewById(R.id.layout_progress);
progressBar = (ProgressBar) findViewById(R.id.progress);
tvNotify = (TextView) findViewById(R.id.tv_notify);
nick = getIntent().getStringExtra(Var.KEY_NICK);
}
private void setupToolbar() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
}
}
private void setupRecyclerView() {
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rv_lover);
// If the size of views will not change as the data changes.
recyclerView.setHasFixedSize(true);
// Setting the LayoutManager.
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
// Setting the adapter.
list = new ArrayList<>();
adapter = new ItemAdapter(context, list);
recyclerView.setAdapter(adapter);
}
public void onResume() {
super.onResume();
refresh();
}
/**
* re load data from server
*/
private void refresh() {
HashMap<String, String> map = new HashMap<>();
map.put(Var.KEY_NICK, nick);
loadJson.sendDataToServer(Var.METHOD_GET_OLD_LOVER, map);
layoutProgress.setVisibility(View.VISIBLE);
progressBar.setVisibility(View.VISIBLE);
tvNotify.setVisibility(View.GONE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_logout:
logout();
break;
case R.id.action_refresh:
refresh();
break;
}
return super.onOptionsItemSelected(item);
}
private void logout() {
Intent intent = new Intent(context, LoginActivity.class);
startActivity(intent);
finish();
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.fab_add:
addOldLover();
break;
}
}
private void addOldLover() {
Intent intent = new Intent(context, AddLoverActivity.class);
intent.putExtra(Var.KEY_NICK, nick);
startActivity(intent);
}
@Override
public void finishLoadJSon(String error, String json) {
if (json != null) {
layoutProgress.setVisibility(View.GONE);
updateList(json);
} else {
showNotify(error);
}
}
private void updateList(String json) {
ArrayList<Lover> newList = LoadJson.jsonToListLover(json);
list.clear();
list.addAll(newList);
adapter.notifyDataSetChanged();
if (list.size() == 0) {
showNotify(context.getResources().getString(R.string.no_lover));
}
}
private void showNotify(String notify) {
layoutProgress.setVisibility(View.VISIBLE);
progressBar.setVisibility(View.GONE);
tvNotify.setVisibility(View.VISIBLE);
tvNotify.setText(notify);
}
/**
* double click back then exit app (2 click in 2s to exit)
*/
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Var.showToast(context, context.getResources().getString(R.string.back_to_exit));
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
}
private boolean doubleBackToExitPressedOnce;
}
In this you are at the bottom of his attention overwriting methods onBackPressed to notify users press back 2 times before escaping. 2 This publication consecutive times to within 2s (200 Milliseconds)
File ItemAdapter.java
package cachhoc.net.demojson;
import android.content.Context;
import android.support.v7.widget.CardView;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
public class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.RecyclerViewHolder> {
private List<Lover> list;
private Context context;
public ItemAdapter(Context context, List<Lover> list) {
this.context = context;
this.list = list;
}
@Override
public int getItemCount() {
return list.size();
}
/**
* connect to item view
*/
@Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View itemView = inflater.inflate(R.layout.item, viewGroup, false);
return new RecyclerViewHolder(itemView);
}
/**
* set data for item
*/
@Override
public void onBindViewHolder(RecyclerViewHolder viewHolder, int position) {
Lover lover = list.get(position);
viewHolder.tvName.setText(lover.getName());
viewHolder.tvPhone.setText(lover.getPhone());
viewHolder.tvBeginDate.setText(lover.getBeginDate());
viewHolder.tvEndDate.setText(lover.getEndDate());
}
/**
* ViewHolder for item view of list
*/
public class RecyclerViewHolder extends RecyclerView.ViewHolder implements
OnClickListener {
public CardView container;
public TextView tvName;
public TextView tvPhone;
public TextView tvBeginDate;
public TextView tvEndDate;
public RecyclerViewHolder(View itemView) {
super(itemView);
container = (CardView) itemView.findViewById(R.id.item_container);
tvName = (TextView) itemView.findViewById(R.id.tv_name);
tvPhone = (TextView) itemView.findViewById(R.id.tv_phone);
tvBeginDate = (TextView) itemView.findViewById(R.id.tv_begin_date);
tvEndDate = (TextView) itemView.findViewById(R.id.tv_end_date);
container.setOnClickListener(this);
}
// click item then display note
@Override
public void onClick(View v) {
Var.showToast(context, list.get(getAdapterPosition()).getName());
}
}
}
So we've completed applications. Last but longish but not difficult.
You can download project here
Download File Chạy OldLover.apk
Chúc các bạn học tập vui vẻ 🙂
Posts made in the tutorial JSon trong Android by nguyenvanquan7826
he asked me https://cachhoc.net/mobile/demo-json/lover.php His brother read this without understanding that come from it
Its made from our database, you see tutorial number 2 nhé
https://www.cachhoc.net/2015/08/18/android-json-trong-android-phan-2-xuat-json-tu-database-bang-php/
Ask yourself 1 chút được không. Mình tạo database sau đó đẩy dữ liệu vào trong database . Dữ liệu mình đưa vào là công thức toán học nên khi vào trong database nó không hiển thị được dẫn đến việc trả ra chuổi JSON cũng không hiển thị được công thức toán học. Bạn cho hình hỏi có cách nào xử lý không? Thanks
Of, About his mathematical formulas have not tried, it is not clear how
Ask yourself can display html tags in html listview k such that?
May I ask you, I did not know that the data is not correctly written in Vietnamese when sending can not be saved to the database on the web, the result is = whitespace, How do you fix this error, and as your JSON L u00f2 L u1ea5p L u00f3, read from Android can decode it properly so as not original. Thank you.
You see retry formatting text on database view, themselves or to be utf-8 unicode
I've corrected it, thank you much, very useful article. Ask yourself if you want to send multiple Array List, instead of sending one, how to just send in 1 times not.
You just entered 1 object that contains the list is
My friend I was like you did not know how to help her handle is not you
You see the font on the database formats watch it. usually UTF8
Waiter, let me ask: em có Link api_url, the POST method to send data to the url that alone can skip class and Lover.java Var.java not it? and class should change how LoadJson.java sir?
Var class just to save the only constant url, you leave well, instead you transfer direct url.