java - Runtime.exec() 不会正确完成

Question

我创建了一个 WebApp，它依赖于外部脚本来收集用户(内部软件)的查询请求。我已经成功地测试了 netbeans 提供的 glassfish 服务器上的 WebApp，但是每当我尝试将我的应用程序上传到第三方服务器(Apache Tomcat)时，我都会遇到 process.getRuntime exitValue 从未被写入的问题，并且WebApp 永远不会进入结果页面....

这是我迄今为止实现的代码:

更新 --> 读取 stderr 和 stdin 后，代码现在可以工作:

        pd = new ProcessBuilder("runscript.bat");
        pd.redirectErrorStream(true);
        process = pd.start();


        StreamGobbler inputGobbler = new StreamGobbler(process.getInputStream(), "Input");
        StreamGobbler errorGobbler = new StreamGobbler(process.getErrorStream(),"Error");

        errorGobbler.start();
        inputGobbler.start();

        int exitVal = -1;

        try {
            exitVal = process.waitFor();
        } catch (InterruptedException ex) {
            //log Error
        }

class StreamGobbler extends Thread {
     OutputWriterReader outWR = new OutputWriterReader();
     BufferedWriter deadWriter;
     InputStream is;

// reads everything from is until empty. 
StreamGobbler(InputStream is, String type) {
    this.is = is;
    createWatch(type);
}
// depending on if Error stream or Input Stream
private void createWatch(String type){
    try {

        if(type.equals("Error"))
            deadWriter = new BufferedWriter(new FileWriter("StdError.txt"));
        else if(type.equals("Input"))
            deadWriter = new BufferedWriter(new FileWriter("StdInput.txt"));

    } catch (IOException ex) {
        //log Error
    }
}

@Override
public void run() {
    try {            
        InputStreamReader isr = new InputStreamReader(this.is);
        BufferedReader br = new BufferedReader(isr);
        String line=null;

        while ( (line = br.readLine()) != null)
            deadWriter.append(line);

        deadWriter.flush();
        deadWriter.close();

    } catch (IOException ioe) {
        //log Error
    }
}

}

任何建议？在此先感谢您的帮助

Answer 1

当您对其调用 exitValue() 时，该过程可能未完成。

在 process.exitValue() 调用之前添加:
process.waitFor();