java - 从 Java 多线程程序中终止特定线程

Question

我正在编写一个 Java 程序，如下所示，该类只是在操作系统级别执行命令。然而，有时我们会遇到程序卡住的问题，因此命令永远不会返回任何状态，因此线程不会终止。

现在我正在尝试增强代码，添加一个额外的东西，我可以在其中杀死特定的线程。我已经捕获了 ThreadId，那么这可行吗？

public class ExecuteCmd implements Runnable {

String ProcessId;
String cmd;
BackendSQL bsql;
Logger myLogger;
Thread myThread;


public ExecuteCmd(String cmd, BackendSQL bsql, String ProcessId, Logger myLogger) { 
   this.ProcessId=ProcessId; 
   this.cmd=cmd; 
   this.bsql=bsql;
   this.myLogger=myLogger;
}

public void run() {
    int rc = 0;

    try {

        long ThreadId = Thread.currentThread().getId();


        bsql.MarkRunning(ProcessId, ThreadId);

        myLogger.debug("[ExecuteCmd] Command is: "+cmd);

        String[] cmdFull = cmd.split(";");

        Runtime rt = Runtime.getRuntime();

        Process p = rt.exec(cmdFull);
        myLogger.info("[ExecuteCmd] [Threading] "+ ThreadId + ": Executing command");
        myLogger.debug("[ExecuteCmd] Command is: "+cmd);


        BufferedReader inStream = new BufferedReader(new InputStreamReader(p.getInputStream()));

        String inStreamLine = null;
        String inStreamLinebyLine=null;
        while((inStreamLine = inStream.readLine()) != null) {
          inStreamLinebyLine = inStreamLinebyLine+"\n"+inStreamLine;
        }
        myLogger.info("Command getInputStream: " + inStreamLinebyLine);



        try {
            rc = p.waitFor();

            if (rc == 0) {
                bsql.MarkCompleted(ProcessId);
            }else{
                bsql.MarkFailed(ProcessId);
            }

        } catch (InterruptedException intexc) {
            System.out.println("Interrupted Exception on waitFor: " +
                               intexc.getMessage());
        }

    }catch (IOException IOE) {
        myLogger.error("IOException[ExecuteCmd]: " + IOE.getMessage());
    }catch (Exception e) {
        myLogger.error("Exception[ExecuteCmd]: " + e.getMessage());
    }
}

}

Answer 1

您应该将 ExecuteCmd 实例提交到 ExecutorService 。这样，您就可以取消或中断您的任务。

Process#waitFor()是一个可中断的操作，所以它应该可以正常工作。

ExecutorService service = Executors.newSingleThreadedExecutor();
Future<?> future = service.submit(new ExecuteCmd(...));
if (takingTooLong()) {
    future.cancel(true);
}