我使用 StreamGobbler 从外部程序读取输出。在我用来读取和解析来自 ffmpeg 的 stderr 的大（20-40 个字符串）输出之前。现在我只想从identify(ImageMagick)的stdout中读取和解析一个字符串（一个字符串是程序的所有输出，这个程序很快结束）。有时它可以工作，但有时我有错误“流已关闭”。我认为 StreamGobbler 没有时间使用流（流程在 streamGobbler 做一些工作之前结束）。
您可以在下面看到类 ExecThread 及其用法示例。
对不起我的英语不好...
String command = ffmpegExe.getAbsolutePath()+ " -i \""+ fileName +"\"";
ExecThread thread = new ExecThread(command);
thread.setPriority(ExecThread.MIN_PRIORITY);
thread.start();
thread.waitFor(DEFAULT_WAIT);
//reading ffmpeg stderr
BufferedReader ffmpegErr = thread.getErrBufferedReader();
String line;
try
{
while((line = ffmpegErr.readLine()) !=null)
//some code
private static class ExecThread extends Thread
{
public ExecThread(String command)
{
this.command = command;
}
@Override
public void run()
{
try
{
ExecCommand(command);
exitVal = process.waitFor();
}
catch (Exception e )
{
logger.error("Error while executing command: " + command + e.getMessage(),e);
System.err.println("Error");
System.exit(1);
}
}
public void waitFor(long millis)
{
try
{
this.join(millis);
process.destroy();
} catch (Exception e)
{
logger.error("Error while interupting command: " + command + e.getMessage(), e);
}
}
private void ExecCommand(String command) throws IOException
{
//run command
Runtime rt = Runtime.getRuntime();
process = rt.exec(new String[]{shellName,shellOption, command}, null, null);
//get stderr buffered reader
StreamGobbler errGobbler = new StreamGobbler(process.getErrorStream());
StreamGobbler outGobbler = new StreamGobbler(process.getInputStream());
ErrBufferedReader = new BufferedReader(new InputStreamReader(errGobbler));
OutBufferedReader = new BufferedReader(new InputStreamReader(outGobbler));
}
private BufferedReader ErrBufferedReader;
public BufferedReader getOutBufferedReader()
{
return OutBufferedReader;
}
private BufferedReader OutBufferedReader;
private Process process;
private String command;
private int exitVal=-1;
public BufferedReader getErrBufferedReader()
{
return ErrBufferedReader;
}
public Process getProcess()
{
return process;
}
public String getCommand()
{
return command;
}
public int getExitVal()
{
return exitVal;
}
}