以下是一个示例代码，演示了如何在Android中使用蓝牙接听和拒绝电话并显示来电号码。

首先，你需要在你的AndroidManifest.xml文件中添加以下权限：

然后，在你的Activity中，你可以使用BluetoothHeadset类来管理蓝牙耳机的连接。下面是一个简单的示例代码：

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothHeadset;
import android.bluetooth.BluetoothProfile;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private BluetoothAdapter mBluetoothAdapter;
    private BluetoothHeadset mBluetoothHeadset;
    private BluetoothProfile.ServiceListener mProfileListener;

    private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            if (action.equals(BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED)) {
                int state = intent.getIntExtra(BluetoothHeadset.EXTRA_STATE, BluetoothHeadset.STATE_DISCONNECTED);

                if (state == BluetoothHeadset.STATE_CONNECTED) {
                    Toast.makeText(MainActivity.this, "Bluetooth Headset connected", Toast.LENGTH_SHORT).show();
                } else if (state == BluetoothHeadset.STATE_DISCONNECTED) {
                    Toast.makeText(MainActivity.this, "Bluetooth Headset disconnected", Toast.LENGTH_SHORT).show();
                }
            } else if (action.equals(TelephonyManager.ACTION_PHONE_STATE_CHANGED)) {
                String state = intent.getStringExtra(TelephonyManager.EXTRA_STATE);

                if (state.equals(TelephonyManager.EXTRA_STATE_RINGING)) {
                    String incomingNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);
                    Toast.makeText(MainActivity.this, "Incoming call from: " + incomingNumber, Toast.LENGTH_SHORT).show();
                } else if (state.equals(TelephonyManager.EXTRA_STATE_OFFHOOK)) {
                    Toast.makeText(MainActivity.this, "Call answered", Toast.LENGTH_SHORT).show();
                } else if (state.equals(TelephonyManager.EXTRA_STATE_IDLE)) {
                    Toast.makeText(MainActivity.this, "Call ended", Toast.LENGTH_SHORT).show();
                }
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        if (mBluetoothAdapter == null) {
            // Device does not support Bluetooth
            Toast.makeText(this, "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
            return;
        }

        mProfileListener = new BluetoothProfile.ServiceListener() {
            @Override
            public void onServiceConnected(int profile, BluetoothProfile proxy) {
                if (profile == BluetoothProfile.HEADSET) {
                    mBluetoothHeadset = (BluetoothHeadset) proxy;
                }
            }

            @Override
            public void onServiceDisconnected(int profile) {
                if (profile == BluetoothProfile.HEADSET) {
                    mBluetoothHeadset = null;
                }
            }
        };

        mBluetoothAdapter.getProfileProxy(this, mProfileListener, BluetoothProfile.HEADSET);
    }

    @Override
    protected void onResume() {
        super.onResume();

        IntentFilter filter = new IntentFilter();
        filter.addAction(BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED);
        filter.addAction(TelephonyManager.ACTION_PHONE_STATE_CHANGED);

        registerReceiver(mBroadcastReceiver, filter);
    }

    @Override
    protected void onPause() {
        super.onPause();

        unregisterReceiver(mBroadcastReceiver);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if (mBluetoothHeadset != null) {
            mBluetoothAdapter.closeProfileProxy(BluetoothProfile.HEADSET, mBluetoothHeadset);
        }
    }
}

上述示例代码中，我们创建了一个BroadcastReceiver来监听蓝牙耳机的连接状态和电话状态。当蓝牙耳机连接或断开连接时，会收到BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED广播。当电话状态改变时，会收到TelephonyManager.ACTION_PHONE_STATE_CHANGED广播。在这些广播的处理代码中，你可以根据需要执行接听电话、拒绝电话和显示来电号码等操作。

请注意，上述示例代码只是一个简单的示例，实际应用中可能需要处理更多的情况和错误处理。还需要在AndroidManifest.xml