在java中如何将十六进制字符串分离为单独的位值？

kzipqqlq  于 2021-09-13  发布在  Java
关注(0)|答案(1)|浏览(440)

使用以下命令成功将字节数组转换为十六进制字符串后：

  1. private ScanCallback leScanCallback = new ScanCallback() {
  2.         @Override
  3.         public void onScanResult(int callbackType, ScanResult result) {
  4.             ScanRecord Scanned = result.getScanRecord();
  5.             String address = btAdapter.getAddress();
  7.             byte[] packetData = Scanned.getBytes();
  8.             StringBuilder R = new StringBuilder();
  9.                 for(byte hex : packetData){
  10.                     R.append(String.format("%02X", hex));
  11.                 }

我想现在有能力读取十六进制流的每一位分别作为数值，以允许对我的ble扫描仪应用程序的值执行基本逻辑。
我读过很多网站，我最初的想法是在for循环中使用数组并读入十六进制字符串的每个字符。但我是java新手，还没有成功做到这一点！
任何关于我如何能有效地做到这一点的想法都会很好。
编辑：
初始输出使用getbytes（）并给出一个字节数组输出，如“[b@”，后跟一些数字和字母。这个值不是我需要的格式，我需要62位十六进制流，由于for循环，它现在已经成功打印了！
现在我想将62位数据包长度的十六进制数据分离为单独的当前值。不将它们转换回字节数组。
希望这能进一步澄清这些要求
编辑：到目前为止完整的代码

  1. package com.example.joelwasserman.androidbletutorial;
  3. import android.Manifest;
  4. import android.app.AlertDialog;
  5. import android.bluetooth.BluetoothAdapter;
  6. import android.bluetooth.BluetoothDevice;
  7. import android.bluetooth.BluetoothManager;
  8. import android.bluetooth.le.BluetoothLeScanner;
  9. import android.bluetooth.le.ScanCallback;
  10. import android.bluetooth.le.ScanFilter;
  11. import android.bluetooth.le.ScanRecord;
  12. import android.bluetooth.le.ScanResult;
  13. import android.content.Context;
  14. import android.content.DialogInterface;
  15. import android.content.Intent;
  16. import android.content.pm.PackageManager;
  17. import android.location.Location;
  18. import android.location.LocationManager;
  19. import android.os.AsyncTask;
  20. import android.os.ParcelUuid;
  21. import android.support.v4.app.ActivityCompat;
  22. import android.support.v4.content.ContextCompat;
  23. import android.support.v7.app.AppCompatActivity;
  24. import android.os.Bundle;
  25. import android.text.method.ScrollingMovementMethod;
  26. import android.util.Log;
  27. import android.util.SparseArray;
  28. import android.view.View;
  29. import android.widget.Button;
  30. import android.widget.TextView;
  32. import java.io.IOException;
  33. import java.io.StringReader;
  34. import java.nio.charset.StandardCharsets;
  36. import java.util.List;
  37. import java.util.UUID;
  38. import java.util.Vector;
  40. public class MainActivity extends AppCompatActivity {
  42.     BluetoothManager btManager;
  43.     BluetoothAdapter btAdapter;
  44.     BluetoothLeScanner btScanner;
  45.     Button startScanningButton;
  46.     Button stopScanningButton;
  47.     TextView peripheralTextView;
  48.     private final static int REQUEST_ENABLE_BT = 1;
  49.     private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
  51.     @Override
  52.     protected void onCreate(Bundle savedInstanceState) {
  53.         super.onCreate(savedInstanceState);
  54.         setContentView(R.layout.activity_main);
  56.         peripheralTextView = (TextView) findViewById(R.id.PeripheralTextView);
  57.         peripheralTextView.setMovementMethod(new ScrollingMovementMethod());
  59.         startScanningButton = (Button) findViewById(R.id.StartScanButton);
  60.         startScanningButton.setOnClickListener(new View.OnClickListener() {
  61.             public void onClick(View v) {
  62.                 startScanning();
  63.             }
  64.         });
  66.         stopScanningButton = (Button) findViewById(R.id.StopScanButton);
  67.         stopScanningButton.setOnClickListener(new View.OnClickListener() {
  68.             public void onClick(View v) {
  69.                 stopScanning();
  70.             }
  71.         });
  72.         stopScanningButton.setVisibility(View.INVISIBLE);
  74.         btManager = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
  75.         btAdapter = btManager.getAdapter();
  76.         btScanner = btAdapter.getBluetoothLeScanner();
  78.         if (btAdapter != null && !btAdapter.isEnabled()) {
  79.             Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
  80.             startActivityForResult(enableIntent,REQUEST_ENABLE_BT);
  81.         }
  83.         // Make sure we have access coarse location enabled, if not, prompt the user to enable it
  84.         if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
  85.             final AlertDialog.Builder builder = new AlertDialog.Builder(this);
  86.             builder.setTitle("This app needs location access");
  87.             builder.setMessage("Please grant location access so this app can detect peripherals.");
  88.             builder.setPositiveButton(android.R.string.ok, null);
  89.             builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
  90.                 @Override
  91.                 public void onDismiss(DialogInterface dialog) {
  92.                     requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
  93.                 }
  94.             });
  95.             builder.show();
  96.         }
  97.     }
  99.     // Device scan callback.
  100.     private ScanCallback leScanCallback = new ScanCallback() {
  101.         @Override
  102.         public void onScanResult(int callbackType, ScanResult result) {
  103.             ScanRecord Scanned = result.getScanRecord();
  104.             String address = btAdapter.getAddress();
  106.             byte[] packetData = Scanned.getBytes();
  108.             /*StringBuilder R = new StringBuilder();
  109.                 for(byte hex : packetData){
  110.                     R.append(String.format("%02X", hex));
  111.                 }*/
  112.             int PacketLength = Scanned.getBytes().length;
  113. //            int x = Integer.parseInt(String.valueOf(packetData));
  114. //            String int_val = Integer.toString(x);
  116.             if(new String("SimpleBLEBroadcaster").equals(result.getDevice().getName()))
  117.                 peripheralTextView.append("Device Name: " + result.getDevice().getName() + " rssi: " + result.getRssi() +" Packet length: " + PacketLength + " Packet Data: " + "0x" + R  +  "\n");
  118.         }
  119.     };
  121.     @Override
  122.     public void onRequestPermissionsResult(int requestCode,
  123.                                            String permissions[], int[] grantResults) {
  124.         switch (requestCode) {
  125.             case PERMISSION_REQUEST_COARSE_LOCATION: {
  126.                 if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
  127.                     System.out.println("coarse location permission granted");
  128.                 } else {
  129.                     final AlertDialog.Builder builder = new AlertDialog.Builder(this);
  130.                     builder.setTitle("Functionality limited");
  131.                     builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons when in the background.");
  132.                     builder.setPositiveButton(android.R.string.ok, null);
  133.                     builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
  135.                         @Override
  136.                         public void onDismiss(DialogInterface dialog) {
  137.                         }
  139.                     });
  140.                     builder.show();
  141.                 }
  142.                 return;
  143.             }
  144.         }
  145.     }
  147.     public void startScanning() {
  148.         System.out.println("start scanning");
  149.         peripheralTextView.setText("");
  150.         startScanningButton.setVisibility(View.INVISIBLE);
  151.         stopScanningButton.setVisibility(View.VISIBLE);
  152.         AsyncTask.execute(new Runnable() {
  153.             @Override
  154.             public void run() {
  155.                 btScanner.startScan(leScanCallback);
  156.             }
  157.         });
  158.     }
  160.     public void stopScanning() {
  161.         System.out.println("stopping scanning");
  162.         peripheralTextView.append("Stopped Scanning");
  163.         startScanningButton.setVisibility(View.VISIBLE);
  164.         stopScanningButton.setVisibility(View.INVISIBLE);
  165.         AsyncTask.execute(new Runnable() {
  166.             @Override
  167.             public void run() {
  168.                 btScanner.stopScan(leScanCallback);
  169.             }
  170.         });
  171.     }
  173.     public static byte[] hexStringToByteArray(String s) throws IOException {
  174.         char[] buf = new char[2];
  175.         int numRead = -1;
  176.         StringReader in = new StringReader(s);
  177.         byte[] bytes = new byte[s.length() / 2];
  178.         int byteIndex = 0;
  179.         while ((numRead = in.read(buf)) > -1) {
  180.             byte b = (byte) Integer.parseInt(String.valueOf(buf), 16);
  181.             bytes[byteIndex++] = b;
  182.         }
  183.         return bytes;
  184.     }
  185. }
JavaandroidHex

1条答案

按热度按时间
roejwanj

roejwanj1#

记住我所说的交通与可视化，你所得到的可以通过以下方式处理：

  1. public static byte[] hexStringToByteArray(String s) throws IOException {
  2.         char[] buf = new char[2];
  3.         int numRead = -1;
  4.         StringReader in = new StringReader(s);
  5.         byte[] bytes = new byte[s.length() / 2];
  6.         int byteIndex = 0;
  7.         while ((numRead = in.read(buf)) > -1) {
  8.             byte b = (byte) Integer.parseInt(String.valueOf(buf), 16);
  9.             bytes[byteIndex++] = b;
  10.         }
  11.         return bytes;
  12.     }
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