如何在Android上读取蓝牙的InputStream

Question

我正在尝试测试PC 和 Android 手机之间的蓝牙通信示例。我的 SPP 客户端正是来自那里的客户端，并且运行良好。我是 Android 新手，我不想让它在单独的线程中运行，因为我不知道如何运行，所以我只是在方法中完成了所有操作onCreate()。如果这不是最好的方法，请随时为我指出更好的方法，但这不是我的主要问题。

问题是我想在 a 上显示通过蓝牙收到的文本textView，但我不知道如何读取InputStream. 当代码像这样留下时，它会显示类似java.io.DataInputStream@41b0cb68 我尝试过的内容，就像这里它没有显示任何内容，而且我不知道正在使用什么编码。

这是我的 Android 应用程序的代码：

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.*;
import android.util.Log;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends Activity {

//based on java.util.UUID
private static UUID MY_UUID = UUID.fromString("446118f0-8b1e-11e2-9e96-0800200c9a66");

// The local server socket
private BluetoothServerSocket mmServerSocket;

// based on android.bluetooth.BluetoothAdapter
private BluetoothAdapter mAdapter;
private BluetoothDevice remoteDevice;
TextView text;

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

    text = (TextView) findViewById(R.id.textView_Text);

    BluetoothSocket socket = null;
    mAdapter = BluetoothAdapter.getDefaultAdapter();        

    // Listen to the server socket if we're not connected
   // while (true) {

        try {
            // Create a new listening server socket
            Log.d((String) this.getTitle(), ".....Initializing RFCOMM SERVER....");

            // MY_UUID is the UUID you want to use for communication
            mmServerSocket = mAdapter.listenUsingRfcommWithServiceRecord("MyService",    MY_UUID);
            //mmServerSocket =  mAdapter.listenUsingInsecureRfcommWithServiceRecord(NAME, MY_UUID); // you can also try  using In Secure connection...

            // This is a blocking call and will only return on a
            // successful connection or an exception
            socket = mmServerSocket.accept();

        } catch (Exception e) {

        }

        try {
            Log.d((String) this.getTitle(), "Closing Server Socket.....");
            mmServerSocket.close();

            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams

            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();

            DataInputStream mmInStream = new DataInputStream(tmpIn);
            DataOutputStream mmOutStream = new DataOutputStream(tmpOut);

            // here you can use the Input Stream to take the string from the client  whoever is connecting
            //similarly use the output stream to send the data to the client


            text.setText(mmInStream.toString());
        } catch (Exception e) {
            //catch your exception here
        }
   // }
}
}

我注释掉了while(true)循环，因为我认为它使我的应用程序在onPause()被调用时崩溃。我知道这不是最好的实现，但我真的想从蓝牙读取，我觉得我非常接近:)，其他方面将在之后处理（例如使用线程等）。

Answer 1

TextView我终于成功地在从 PC 发送的字符串中正确显示（“来自 SPP 客户端的测试字符串\r\n”）。

我使用了这个问题，即这段代码，如下DataOutputStream mmOutStream = new DataOutputStream(tmpOut);：

// Read from the InputStream
            bytes = mmInStream.read(buffer);
            String readMessage = new String(buffer, 0, bytes);
            // Send the obtained bytes to the UI Activity

这是一个非常基本的示例，仅用于展示如何在设备屏幕上显示通过蓝牙接收的字符串。它不是在单独的线程中完成的，在收到字符串后，您必须关闭应用程序并再次重新启动它，但应用程序的主要目的已经实现（正如我在问这个问题时所说的那样）。我真正真正想要的是从 PC 接收一个字符串并将其显示在屏幕上。

这是我的完整内容MainActivity，如果有人希望我发布更完整的方法（例如使用单独的线程），我将在完成后将其发布在这里。

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.*;
import android.util.Log;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends Activity {

//based on java.util.UUID
private static UUID MY_UUID = UUID.fromString("446118f0-8b1e-11e2-9e96-0800200c9a66");

// The local server socket
private BluetoothServerSocket mmServerSocket;

// based on android.bluetooth.BluetoothAdapter
private BluetoothAdapter mAdapter;
private BluetoothDevice remoteDevice;
TextView text;

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

    text = (TextView) findViewById(R.id.textView_Text);

    BluetoothSocket socket = null;
    mAdapter = BluetoothAdapter.getDefaultAdapter();        

    // Listen to the server socket if we're not connected
   // while (true) {

        try {
            // Create a new listening server socket
            Log.d((String) this.getTitle(), ".....Initializing RFCOMM SERVER....");

            // MY_UUID is the UUID you want to use for communication
            mmServerSocket = mAdapter.listenUsingRfcommWithServiceRecord("MyService",    MY_UUID);
            //mmServerSocket =  mAdapter.listenUsingInsecureRfcommWithServiceRecord(NAME, MY_UUID); // you can also try  using In Secure connection...

            // This is a blocking call and will only return on a
            // successful connection or an exception
            socket = mmServerSocket.accept();

        } catch (Exception e) {

        }

        byte[] buffer = new byte[256];  // buffer store for the stream
        int bytes; // bytes returned from read()
        try {
            Log.d((String) this.getTitle(), "Closing Server Socket.....");
            mmServerSocket.close();

            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams

            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();

            DataInputStream mmInStream = new DataInputStream(tmpIn);
            DataOutputStream mmOutStream = new DataOutputStream(tmpOut);            
            // here you can use the Input Stream to take the string from the client  whoever is connecting
            //similarly use the output stream to send the data to the client

         // Read from the InputStream
            bytes = mmInStream.read(buffer);
            String readMessage = new String(buffer, 0, bytes);
            // Send the obtained bytes to the UI Activity


            text.setText(readMessage);
        } catch (Exception e) {
            //catch your exception here
        }
   // }
}
}

任何问题？:)