java java使一个方法等待另一个进程的响应
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/7713786/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
java make a method wait for a response of another process
提问by zhujik
In my program, I connect to an interpreter process for another language. I need the program sometimes to ask the interpreter several things and use it's response.
在我的程序中，我连接到另一种语言的解释器进程。我有时需要该程序向解释器询问几件事并使用它的响应。
The process is stored in a IProcess variable and the communication is done via the IStreamsProxy of the process. to recieve the response, I added an IStreamListener to the IStreamsProxy.
进程存储在 IProcess 变量中，通信通过进程的 IStreamsProxy 完成。为了接收响应，我向 IStreamsProxy 添加了一个 IStreamListener。
However, when I write to the IStreamsProxy (with the write() method), I need the code to wait for the response, e.g. the streamAppend-method of the listener to be called.
但是，当我写入 IStreamsProxy（使用 write() 方法）时，我需要等待响应的代码，例如要调用的侦听器的 streamAppend 方法。
I tried to use the wait() and notify() method, but I don't know on what objects I should call them.
我尝试使用 wait() 和 notify() 方法，但我不知道应该在哪些对象上调用它们。
The query class which makes the communication calls a method like this:
进行通信的查询类调用如下方法：
/**
* Sends a command to the interpreter. Makes the current thread wait for an answer of the interpreter.
* @throws IOException
*/
private synchronized void send(String command) throws IOException{
this.s48Proxy.write(command);
try {
System.out.println("waiting for reply");
this.wait();
} catch (InterruptedException e) {
System.out.println("interruption exception: "+e.getMessage());
}
}
and the listener:
和听众：
private class Listener implements IStreamListener {
private Query query;
public Listener(Query query) {
super();
this.query = query;
}
@Override
public void streamAppended(String arg0, IStreamMonitor arg1) {
System.out.println("got interpreter answer");
query.setCurrentOutput(arg0.substring(0, arg0.lastIndexOf("\n")).trim());
query.notify();
}
}
The streamAppend()method calls the notify()-method on the query class. However, this does not work. "Waiting for reply"is the last response I get.
该streamAppend()方法调用notify()查询类上的 -method。但是，这不起作用。“等待回复”是我得到的最后一个回复。
How can I do this? Or are there any other methods I could use to achieve this automatically?
我怎样才能做到这一点？或者我可以使用其他任何方法来自动实现这一目标吗？
回答by MasterCassim
You could use Object#wait& Object#notifiy.
你可以使用Object#wait& Object#notifiy。
// @ IStreamsProxy
synchronized( someMonitor ) {
someMonitor.wait( /* time? */ );
}
// @ Listener
synchronized( someMonitor ) {
someMonitor.notify();
}
-> Javadoc Link
-> Javadoc 链接
回答by Thom
Use a semaphore like boolean waitingForResponse. Set this to true when you make your call, then go into
使用像 boolean waitingForResponse 这样的信号量。拨打电话时将此设置为 true，然后进入
while(waitingForResponse){ sleep(99) //should be your average response time from your call }
while(waitingForResponse){ sleep(99) // 应该是您呼叫的平均响应时间 }
In your listener, set waitinForResponse to false.
在您的侦听器中，将 waitinForResponse 设置为 false。
