I have a project of a chat socket running in Swing and now I'm passing it to Android.
It was all working perfectly until I put the code that makes the magic happen. The application closed and I did not know why it had already fixed all the errors of the code itself.
I went through the debug and found the error saying that I could not instantiate anything before onCreate() . As you can see there is nothing before him (visibly).
I asked some teachers and they told me that the problem could be in the life cycle of my activity. I have not found the error yet. In theory the code is right.
My MainActivity.java:
package com.lucas.appchat;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.GradientDrawable;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
public class MainActivity extends AppCompatActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.message = new ChatMessage();
this.message.setAction(ChatMessage.Action.CONNECT);
this.message.setName(nome);
this.service = new ClienteService();
this.socket = this.service.connect();
new Thread(new ListenerSocket(this.socket)).start();
this.service.send(message);
}
public void btnEnviar(View view) {
btnEnviarActionPerformed();
}
public MessageViewHolder holder = new MessageViewHolder();
public LayoutInflater messageInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
private Socket socket;
private ChatMessage message;
private ClienteService service;
private ObjectOutputStream outputStream;
public EditText txtAreaSend = findViewById(R.id.textBox);
ListView listOnlines2;
String[] array;
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, array);
private class ListenerSocket implements Runnable {
private ObjectInputStream input;
public ListenerSocket(Socket socket) {
try {
this.input = new ObjectInputStream(socket.getInputStream());
} catch (IOException ex) {
Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
}
}
@Override
public void run() {
ChatMessage message;
try {
while ((message = (ChatMessage) input.readObject()) != null) {
ChatMessage.Action action = message.getAction();
if (action.equals(ChatMessage.Action.CONNECT)) {
connected(message);
} else if (action.equals(ChatMessage.Action.DISCONNECT)) {
refreshOnlines(message);
disconnected();
socket.close();
} else if (action.equals(ChatMessage.Action.SEND_ONE)) {
receive(message);
} else if (action.equals(ChatMessage.Action.USERS_ONLINE)) {
refreshOnlines(message);
}
}
} catch (IOException ex) {
Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void connect(ChatMessage message1) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
}
private void connected(ChatMessage message) {
if (message.getText().equals("NO")) {
Toast.makeText(MainActivity.this, "Coneão não realizada!\nTente novamente com um novo nome.", Toast.LENGTH_SHORT).show();
message.setAction(ChatMessage.Action.DISCONNECT);
this.service.send(message);
disconnected();
return;
}
Toast.makeText(MainActivity.this, "Você está conectado no chat!", Toast.LENGTH_SHORT).show();
}
private void disconnected() {
Toast.makeText(MainActivity.this, "Você saiu do Chat!", Toast.LENGTH_SHORT).show();
}
private void receive(ChatMessage message) {
View convertView;
convertView = messageInflater.inflate(R.layout.their_message, null);
holder.avatar = (View) convertView.findViewById(R.id.avatar);
holder.name = (TextView) convertView.findViewById(R.id.name);
holder.messageBody = (TextView) convertView.findViewById(R.id.message_body);
convertView.setTag(holder);
holder.name.setText(message.getName());
holder.messageBody.setText(message.getText());
GradientDrawable drawable = (GradientDrawable) holder.avatar.getBackground();
drawable.setColor(Color.parseColor(message.getRandomColor()));
}
private void refreshOnlines(ChatMessage message) {
System.out.println(message.getSetOnlines().toString());
Set<String> names = message.getSetOnlines();
names.remove(message.getName());
array = (String[]) names.toArray(new String[names.size()]);
listOnlines2.setAdapter(arrayAdapter);
}
private void btnEnviarActionPerformed() {
String text = this.txtAreaSend.getText().toString();
String name = this.message.getName();
this.message = new ChatMessage();
this.message.setAction(ChatMessage.Action.SEND_ALL);
if (!text.isEmpty()) {
this.message.setName(name);
this.message.setText(text);
View convertView;
convertView = messageInflater.inflate(R.layout.my_message, null);
holder.messageBody = (TextView) convertView.findViewById(R.id.message_body);
convertView.setTag(holder);
holder.messageBody.setText(message.getText());
this.service.send(this.message);
}
this.txtAreaSend.setText("");
}
private void btnSairActionPerformed() {
ChatMessage message = new ChatMessage();
message.setName(this.message.getName());
message.setAction(ChatMessage.Action.DISCONNECT);
this.service.send(message);
disconnected();
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:clipToPadding="false"
android:focusableInTouchMode="true"
tools:context=".MainActivity">
<ListView
android:id="@+id/messagesView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="2"
android:divider="#fff" />
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fff"
android:orientation="horizontal">
<EditText
android:id="@+id/textBox"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="2"
android:ems="10"
android:hint="Escrever..."
android:inputType="text"
android:paddingHorizontal="10dp"
android:text="" />
<ImageButton
android:id="@+id/buttonSend"
android:onClick="btnEnviar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginHorizontal="10dp"
android:padding="20dp"
android:scaleType="fitCenter"
android:src="@android:drawable/ic_menu_send" />
</LinearLayout>
Errors registered to the debug:
E/AndroidRuntime: FATAL EXCEPTION: main java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.stevenilson.appchat/com.stevenilson.appchat.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate() at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2038) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2139) at android.app.ActivityThread.access$700(ActivityThread.java:143) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:4960) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate() at android.app.Activity.getSystemService(Activity.java:4582) at com.stevenilson.appchat.MainActivity.<init>(MainActivity.java:49) at java.lang.Class.newInstanceImpl(Native Method) at java.lang.Class.newInstance(Class.java:1319) at android.app.Instrumentation.newActivity(Instrumentation.java:1068) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2029) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2139) at android.app.ActivityThread.access$700(ActivityThread.java:143) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:4960) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) at dalvik.system.NativeStart.main(Native Method)