我有一个类，可以从串行端口接收和发送信息：
public class Terminal implements Runnable
{
static LinkedList<String> receiver = new LinkedList<String>();
public Terminal()
{
//...
}
public String getReceivedMessage()
{
String data = receivedMessfges.removeFirst();
return data;
}
// Other function that perform connection to COM port
// ...
}
我还有基于 Swing 的 gui 类：
public class Gui extends JFrame
{
// Functions that display information, received from COM port
}
Terminal使用Gui第三类传递信息的正确方法是什么：
public class Monitor
{
static Gui gui;
static terminal terminal;
public static void main(String args[])
{
monitor = new Monitor();
}
public Monitor()
{
gui = new Gui();
terminal = new Terminal();
}
// Functions, that get information COM port
// using getReceivedMessage() function
// and display it on Gui
}
谢谢）
我将使用该类在和Monitor之间进行通信。GuiTerminal
如果receivedMessfges.removeFirst();直到收到应在 GUI 中显示的完整消息后才返回，您可以这样做：
Thread messageChecker = new Thread(new Runnable() {
public void run() {
while (!Thread.isInterrupted()) {
String message = terminal.getReceivedMessage();
// Prepare message for gui display
SwingUtilities.invokeLater(new Runnable() {
public void run() {
gui.methodToDisplayTheReceivedMessage(message);
}
}
}
}
}).start();
班级内的某个地方Monitor。
该代码执行以下操作：
- 创建一个新的 Runnable （匿名类）
- 通过一种
run()方法，我们- 检查线程是否被中断
- 如果有，停止
- 如果没有，请等到我们收到来自 的新消息并将其发送到 GUI。
- 通过一种
- 创建一个新的线程集来执行
run()我们新的 Runnable 的方法 - 启动这个线程。
- 将对线程的引用分配给变量
messageChecker。
要停止线程，只需调用messageChecker.interrupt();.
另一方面，如果terminal.getReceivedMessage();仅返回部分消息，即在我们调用它之前收到的消息，我认为最好的方法是使用观察者模式。
- 使终端类实现该接口
Observable - 使Monitor类实现该接口
Observer
Then, you need to write code to notify the observers of a complete message as soon as the terminal class has one. I would suggest to have a Thread internal to the Terminal class checking periodically for new data. As soon as it has a complete message, it should call notifyObservers(message) (with message obviously being a variable of type String containing the complete message).
In the Monitor class, you have to have an update(Observable o, Object arg) method to satisfy the Observer interface:
// In the Monitor class
void update(Observable terminal, Object message) {
SwingUtilities.invokeLater(new Runnable() {
gui.methodToDisplayTheReceivedMessage((String)message); // This cast is safe, since we only ever call notifyObservers() with a string argument.
}
}
Last but not least, you need to call terminal.addObserver(this); from the Monitor class (from the constructor, probably), otherwise notifyObservers() will notify all your 0 observers and nothing happens.
Googling for the "java observer pattern" yields lots of useful resources and examples, in case you want to know more about it.
您可以使用外部接口，例如将数据写入文件并从那里读取......