java - Servlet Loop 函数调用直到 while 循环的结果

Question

我有这个问题:

我有一个功能可以正常工作，但关闭窗口所需的时间比我可以处理的时间长。所以我有另一个函数，如果另一个窗口完成，它会检查任务列表调用。它只检查一次，所以我需要让它检查一遍又一遍，直到完成。

校验函数:

private int getWin() {
     Process Checkprocess;
     try {
     String Checkcommand = "cmd /c tasklist /V /FI \"WINDOWTITLE eq Admin:*\"";
        Checkprocess = Runtime.getRuntime().exec(Checkcommand);
        String Checkline;
        String Checkval="PID";

        is = new BufferedReader(new InputStreamReader(Checkprocess.getInputStream()));
         while((Checkline = is.readLine()) != null) {
             retval = Checkline.contains(Checkval);
             if (retval)
             test = 1;
             else
             test = 0;
         }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return test;     
 }

如果 false 应该返回 0，如果有一个带有该标题的窗口则应该返回 1。

整个来源:

 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.sql.Timestamp;
 import java.text.SimpleDateFormat;
 import java.util.concurrent.TimeUnit;



 public class RunCommand extends HttpServlet {

/**
 * 
 */
private static final long serialVersionUID = 5711290708294275382L;
String commands= null;
//this could be set to a specific directory, if desired
File dir = null;
BufferedReader is = null;
BufferedReader es = null;
boolean retval;
int test;
private BufferedReader outfile;

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
     performTask(request, response);
 }

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {

        performTask(request, response);
 }


 private int getWin() {
     Process Checkprocess;
     try {
     String Checkcommand = "cmd /c tasklist /V /FI \"WINDOWTITLE eq Admin:*\"";
        Checkprocess = Runtime.getRuntime().exec(Checkcommand);
        String Checkline;
        String Checkval="PID";


        is = new BufferedReader(new InputStreamReader(Checkprocess.getInputStream()));
         while((Checkline = is.readLine()) != null) {
             retval = Checkline.contains(Checkval);
             if(retval)
             test = 1;
             else
             test = 0;

             System.out.println("HERE test" + retval);

         }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return test;     
 }

private void performTask (HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {  
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out= response.getWriter();
    try
{
    String commandbuild = request.getParameter("commandinput");
    String commandfilename = request.getParameter("commandfile");

    final SimpleDateFormat datefor = new SimpleDateFormat("ddMMyyyy_HHmmss");
    Timestamp timestamp = new Timestamp(System.currentTimeMillis());
    String timeadd = datefor.format(timestamp);
    System.out.println(timeadd);
    String completefilename = "C:\\tmp\\" + commandfilename +"_"+ timeadd + ".txt ";

    String commandfull = "db2 -tvz "+ completefilename + commandbuild ;

    commands= "cmd /c db2cwadmin.bat " + commandfull;
    //System.out.println(commands);
    Process process;
    if (dir != null)
        process = Runtime.getRuntime().exec(commands, null, dir);
    else
        process = Runtime.getRuntime().exec(commands);
    String line;
    StringBuilder data = new StringBuilder();

    is = new BufferedReader(new InputStreamReader(process.getInputStream()));
    data.append("Command: " + commands);
    data.append("\n\n\n");


    while((line = is.readLine()) != null) {
        //System.out.println(line);

        data.append(line);
        data.append("\n");

    }
    es = new BufferedReader(new InputStreamReader(process.getErrorStream()));
    while((line = es.readLine()) != null)
        System.err.println(line);


    int exitCode = process.waitFor();
    if (exitCode == 0) {
        System.out.println("It worked");

        while(test != 1) {
            getWin();
            if (test == 1)
            break;
        }

        Process EndProcess;
        String Endcommands = "taskkill /F /FI \"WINDOWTITLE eq Admin:*\"";
        EndProcess = Runtime.getRuntime().exec(Endcommands);
        int exitCodeEnd = EndProcess.waitFor();
        System.out.println(exitCodeEnd);

        //TimeUnit.SECONDS.sleep(10);


        data.append("Window closed!");
        data.append("\n");
        data.append("\n");


        outfile = new BufferedReader(new FileReader(completefilename));
        String outfilelines;

        while( (outfilelines = outfile.readLine()) != null ) {
            data.append(outfilelines);
            data.append("\n");

        }

    request.setAttribute("data", data);
    out.append(data);
    RequestDispatcher dispatcher= request.getRequestDispatcher("runCommand.jsp");
    dispatcher.forward(request, response);

    }
    else
        System.out.println("Something bad happend. Exit code: " + exitCode);


} //try
catch(Exception e)
{
    System.out.println("Something when wrong: " + e.getMessage());
    e.printStackTrace();
} //catch
finally
{
    if (is != null)
        try { is.close(); } catch (IOException e) {}
    if (es != null)
        try { es.close(); } catch (IOException e) {}
} //finally


 }}

问题是，即使 getWin 返回真(有一个 println() 来检查)，while 循环也没有退出并且 prog 没有继续。此外，它返回 true 而不是继续并返回几个 false 而不是 true 等等

当 test 为 1 时如何退出 while 循环？

谢谢

Answer 1

How can I have the while loop quit when test is 1?

您可以使用 break

  if (retval){
   test = 1;
   break; //exit loop
  }else{
   test = 0;
  }