遍历Set集合遇到 NoSuchElementException 解决

今天正在整理蓝牙相关的知识，得到该设备与其配对成功的设备集合，返回的集合类型为set，好久不用set集合了，都忘记该如何

遍历了，用这篇博客来记录一下并标记遇到的奇葩问题

这里依旧用获取配对设备的集合举例

 BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        Set bondedDevices = mBluetoothAdapter.getBondedDevices();
        Iterator iterator = bondedDevices.iterator();
        while (iterator.hasNext()) {
           Log.e("ida", iterator.next().getName()+"");
            if (iterator.next().getName().equals("BleServer")) {
                Log.e("ida", "准备通信吧");
            }
        }

  这样看貌似没有什么问题，我运行了一下，出错了

 

05-04 15:03:26.967 22984-22984/com.android.bluetoothclient E/ida: BleServer
05-04 15:03:26.968 22984-22984/com.android.bluetoothclient D/AndroidRuntime: Shutting down VM
05-04 15:03:26.969 22984-22984/com.android.bluetoothclient E/AndroidRuntime: FATAL EXCEPTION: main
                                                                             Process: com.android.bluetoothclient, PID: 22984
                                                                             java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.bluetoothclient/com.android.bluetoothclient.MainActivity}: java.util.NoSuchElementException
                                                                                 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
                                                                                 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
                                                                                 at android.app.ActivityThread.-wrap12(ActivityThread.java)
                                                                                 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                 at android.os.Looper.loop(Looper.java:154)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                                              Caused by: java.util.NoSuchElementException
                                                                                 at java.util.HashMap$HashIterator.nextEntry(HashMap.java:854)
                                                                                 at java.util.HashMap$KeyIterator.next(HashMap.java:885)
                                                                                 at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1115)
                                                                                 at com.android.bluetoothclient.MainActivity.onCreate(MainActivity.java:25)
                                                                                 at android.app.Activity.performCreate(Activity.java:6664)
                                                                                 at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
                                                                                 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
                                                                                 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                                                                                 at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                                                                                 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                 at android.os.Looper.loop(Looper.java:154) 
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6077) 
                                                                                 at java.lang.reflect.Method.invoke(Native Method) 
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 

通过Log看，打印出了名字，但问题就出在那一行，具体原因我也不知道，解决方法如下

 while (iterator.hasNext()) {
            String name = iterator.next().getName();
            Log.e("ida", name+"");
            if (name.equals("BleServer")) {
                Log.e("ida", "准备通信吧");
            }
        }

当然还有另外一种遍历方法

   for (BluetoothDevice device : bondedDevices) {
            if (device.getName().equals("BleServer")) {
                address = device.getAddress();
            }
        }