Trying to code an android app through eclipse to register bluetooth proximity, crashing on startup

Question

I am writing an app that will eventually use Bluetooth to get a value for two devices' proximity to one another. I am currently trying to use buttons and onClick/onclicklistener etc to bring switch screens from the main UI to a log in or sign up page. Now my app is forcing close on start up and I'm not sure why. Thanks for any help!!

MainActivity:

package com.example.chirp;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;


public class MainActivity extends Activity {

    BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter() ;

    String status; {
    if (bluetooth != null)
    {

        if (bluetooth.isEnabled())
        {
            String mydeviceaddress = bluetooth.getAddress();
            String mydevicename = bluetooth.getName();
            status = mydevicename + ":" + mydeviceaddress;
        }
        else
        {
            status = "Bluetooth is not Enabled.";
        }
        }
    Toast.makeText(this, status, Toast.LENGTH_LONG).show();
    }   

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button loginbutton = (Button) findViewById(R.id.button1);
        loginbutton.setOnClickListener(new OnClickListener(){
            public void onClick(View v){
                setContentView(R.layout.loginscreen);               


            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true; 
    }

    public void newMessage(View v){
        Intent intent = new Intent(this,loginscreen.class);
        startActivity(intent);
    }
    }

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#7FFFD4"
    android:padding="20dp"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <!-- <public void loginhere(View view) {
        android:        
        }/>-->

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_gravity="center"

        android:text="@string/hello_world"
        android:textSize="50sp"
        android:typeface="serif" />

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_marginTop="100dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="32sp"
        android:layout_gravity="center_horizontal"
        android:text="Slide to Quick Find"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <Button
        android:id="@+id/button2"
        android:layout_width="396dp"
        android:layout_height="100dp"
        android:layout_marginLeft="75dp"
        android:layout_marginTop="300dp"
        android:textSize="50sp"
        android:text="Sign Up" />

    <Button
        android:id="@+id/button1"
        android:layout_width="396dp"
        android:layout_height="100dp"
        android:layout_marginLeft="75dp"
        android:layout_marginTop="50dp"
        android:textSize="50sp"
        android:onClick="onclick"
        android:text="Log In" />

</LinearLayout>

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.chirp"
    android:versionCode="1"
    android:versionName="1.0" >


    <uses-permission android:name="android.permission.BLUETOOTH"/>

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="18" />
    <supports-screens 
        android:resizeable="true"
        android:smallScreens="true"
        android:normalScreens="true"
        android:largeScreens="true"
        android:xlargeScreens="true"
        android:anyDensity="true"
        android:requiresSmallestWidthDp="320"/>
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.chirp.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.example.chirp.loginscreen"
            android:label="CHIRP"
             />


        </application>

</manifest>

loginscreen.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#7FFFD4"
    android:padding="20dp"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".login" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Username"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textEmailAddress" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Password"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPassword" >

        <requestFocus />
    </EditText>

    <CheckBox
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Remember Username" />

/


</LinearLayout>

Answer 1

Move this code inside your onCreate method:

if (bluetooth != null) {

    if (bluetooth.isEnabled()) {
        String mydeviceaddress = bluetooth.getAddress();
        String mydevicename = bluetooth.getName();
        status = mydevicename + ":" + mydeviceaddress;
    } else {
        status = "Bluetooth is not Enabled.";
    }
    //etc...

Currently this code block is outside of any method of your activity and that is for sure not what you want to have.