我会给你一些建议。我的示例不是工作代码，只是您的工作基础。
首先，我强烈建议您在服务器中使用线程。每次客户端连接到服务器时，您都会创建一个新线程，其参数包含启动它所需的所有数据：
boolean running = true; //this class variable will allow you to shut down the server correctly
public void stopServer(){ //this method will shut down the server
this.running = false;
}
public void run() {
...
while(running) {
// if(this.connection == null) { // I removed this line since it's unnecessary, or even harmful!
StreamConnection connection = this.server.acceptAndOpen(); //This line will block until a connection is made...
System.out.println("INFO: Bluetooth client connected");
Thread thread = new ServerThread(connection);
thread.start() //don't forget exception handling...
}
}
在 ServerThread 类中，您实现了处理客户端的这些行（非编译代码，没有异常处理！）：
Class ServerThread extends Thread {
StreamConnection connection;
public ServerThread(StreamConnection connection){
this.connection = connection;
}
public void run() {
...
connection.close(); //closing the connection...don't forget exception handling!
System.out.println("INFO: Client disconnected");
}
}
这段代码有什么好处？您的服务器现在能够同时处理一千个客户端。您已经进行了并行化，这就是服务器通常的工作方式！没有线程的服务器就像没有鞋子的袜子......
其次，如果您有 Java 客户端和 Java 服务器，则可以使用更简单的方法将对象发送到服务器：ObjectOutputStream/ObjectInputStream。您只需将包含联系人的数组（我将像往常一样使用 ArraList）发送到服务器，然后读取该数组。这是服务器的代码（同样未编译且没有任何异常处理）：
Class ServerThread extends Thread {
StreamConnection connection;
public ServerThread(StreamConnection connection){
this.connection = connection;
}
public void run() {
BufferedInputStream bis = new BufferedInputStream(this.connection.openInputStream());
ObjectInputStream ois = new ObjectInputStream(bis);
ArrayList contacts = (ArrayList) ois.readObject(); //this is a cast: don't forget exception handling!
//You could also try the method ois.readUTF(); especially if you wanna use other non-Java clients
System.out.println("INFO: Received from Bluetooth: " + contacts);
this.connection.close(); //closing the connection...don't forget exception handling!
//ois.close(); //do this instead of "this.connection.close()" if you want the connection to be open...i.e. to receive more data
System.out.println("INFO: Client disconnected");
//here you do whatever you wanna do with the contacts array, maybe add to your other contacts?
}
}
在 Java 中，每个类都是一个对象，包括 ArrayList。并且由于对象的结束将被视为断开连接，因此您无需执行任何其他操作。
第三：您使用上述服务器不仅用于蓝牙连接，还用于 WLAN 连接，aso。然后您可以轻松地启动不同的线程，例如在伪代码if(connection.isBluetooth()){//create a thread from BluetoothThread} else if(connection.isWLAN()){//create a thread from WLANsThread}中。我不知道您的应用程序是关于什么的，但也许有一天您想将其扩展到台式机，因此使用 WLAN 将是正确的选择。还因为您无论如何都需要在客户端中构建验证（“哪些联系人将被发送到哪个服务器？”），无论是蓝牙还是WLAN，因为蓝牙的低范围不能给你任何安全性. ;)
第四，最后关于您的问题：要获得某些东西，您需要有一个数据源和/或一个类变量。这是一个简短的示例，其中包含一个存储联系人的文件（但它也可以是数据库......本地或其他地方！）：
public class MyApp(){
ArrayList contacts;
...
public void run(){ //this happens when we start our app
this.contacts = new ArrayList();
FileReader fr = new FileReader ("C:\WhereverYourFileIs\Contacts.file");
BufferedReader br = new BufferedReader(fr);
//here you use a loop to read the contacts via "br" from the file and fill them into your array...I can't provide you more code, since the exact data structure is up to you.
}
//now we want to send our contacts array to the already connected server:
public sendArrayToServer() {
BufferedOutputStream bos = new BufferedOutputStream (this.connection.openOutputStream());
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(this.contacts);
//If you use readUTF() in the server, you need to call here something like oos.writeUTF(this.contacts.toString()); or even need to use another parser method which exactly creates the string you want.
this.connection.close(); //closing the connection...don't forget exception handling!
//oos.close(); //do this instead of "this.connection.close()" if you want the connection to stay open...
}
}
现在在服务器中，您只需读出上面已经描述的联系人数组。您如何处理这些联系人仍取决于您。
希望这可以帮助您了解您的问题并找到解决方案。编程就是反复试验……和改进你的代码。
编辑：
经过我们的讨论，我终于找到了你需要的东西：你需要一个名为 BluetoothManager 的单线程服务器，它与另一个名为 GUIController 的线程交互。现在，既然我无论如何都在脑海中完成了实现，我可以为您发布它，并附上一些解释。请注意，在这种情况下，您不需要在服务器中初始化另一个线程，因为 BluetoothManager 已经是一个线程，而且您同时只需要一个连接（问题仍然存在，如果那是一个“服务器” ，我宁愿称它为“接收器”）：
Public class BluetoothManager extends Thread{
boolean running = true; //this class variable will allow you to shut down the server correctly
GUIController controller;
public BluetoothManager(GUIController controller){
this.controller = controller; //this registers the GUIController in the BluetoothManager
}
public void stop(){ //this method will shut down the "server"
this.running = false;
}
public void run() {
this.localDevice = LocalDevice.getLocalDevice();
this.localDevice.setDiscoverable(DiscoveryAgent.GIAC);
this.server = (StreamConnectionNotifier) Connector.open(URL);
while(running){
StreamConnection connection = this.server.acceptAndOpen(); //This line will block until a connection is made...or running==false!
System.out.println("INFO: Bluetooth client connected");
BufferedInputStream bis = new BufferedInputStream(this.connection.openInputStream());
ObjectInputStream ois = new ObjectInputStream(bis);
ArrayList contacts = (ArrayList) ois.readObject(); //this is a cast: don't forget exception handling!
System.out.println("INFO: Received from Bluetooth: " + contacts);
this.connection.close(); //closing the connection...don't forget exception handling!
System.out.println("INFO: Client disconnected");
this.controller.refreshContacts(contacts);
}
}
}
public class GUIController extends Thread implements Runnable {
ArrayList contacts; //also a HashMap may be appropriate
BluetoothManager manager;
public void run(){
this.contacts = new ArrayList();
FileReader fr = new FileReader ("C:\WhereverYourFileIs\Contacts.file");
BufferedReader br = new BufferedReader(fr);
//here you use a loop to read the contacts via "br" from the file and fill them into your array...I can't provide you more code, since the exact data structure is up to you.
}
public void startBluetoothManager(){ //starting the BluetoothManager
this.manager = new BluetoothManager(this);
this.manager.start();
}
public void abortBluetoothManager(){ //call this when clicking on the "Abort" button
this.manager.stop();
//now the next 2 lines you normally don't need...still may use it if you've problems shutting down the thread:
// try{ this.manager.interrupt(); } //we want to be 100% sure to shut down our thread!
// catch(Exception e){}
this.manager = null; //now the garbage collector can clean everything...byebye
}
public void refreshContacts(ArrayList contacts) {
// synchronize(this.contactArray){ //no synchronisation needed if you have a GUI pop-up with an "Abort"-button!
Iterator i = this.contacts.iterator();
while(i.hasNext()){
this.contacts.add(i.next());
}
//At the end you need remove the "Receiving message" pop-up together with the "Abort Receiving"-button, these are all class variables!
// important note: If you have unique entries, you may need to replace them! In this case I suggest storing all contact objects better in a HashMap contacts, and use the unique ID as a key to find the element. And then you may prompt the user, if there are identical entries, to overwrite each entry or not. These things remain all up to you.
}
}
//As always: This is no compiled code!!
GUIController 首先运行 BluetoothManager startBluetoothManager()，除了显示通知“接收联系人”和“中止 Reveiving”按钮外，什么都不做。当 BluetoothManager 完成后，他只需通过调用将新联系人添加到 GUIController 内的现有联系人数组中refreshContacts(...)。如果您按下“Abort Reveiving”按钮，您会立即调用该abortBluetoothManager()方法，该方法设置running=false在 BluetoothManager 中以结束服务器并完成线程。
该解决方案解决的主要问题：两个线程无法直接相互通信！一旦你调用thread.start()，每个线程都是独立的。这就是为什么 BluetoothManager 线程不可能告诉 GUIController 线程“我已经完成了！”。这些线程唯一能做的就是共享相同的资源，并通过这些资源进行通信。在我们的例子中，它是contactsGUIController 中的 -ArrayList，首先我认为它需要同步并且可以由两个线程更新（但不能同时更新）。而且 - 有点有趣 - 还有第二个共享资源，它实际上是runningBluetoothManager 类中的标志，可以将其关闭（但从来不需要任何同步running，
现在关于同步：我更多地考虑了这个问题并理解了，您也可以在没有任何“同步（...）”调用的情况下解决您的问题。因此，如果您不想同步 ArrayList，则必须这样做：在服务器运行时，您只显示“接收联系人”弹出窗口和“中止接收”按钮。发生这种情况时，您永远不会访问 GUIController 内的contact-ArrayList。这在某种程度上是一种“内在同步”，不需要真正的 Java 同步。您仍然可以实现同步，只是为了 100% 确保将来扩展应用程序时不会发生任何事情。