等待进程类的方法没有返回

时间:2015-06-26 06:20:19

标签: java process bufferedreader runtime.exec

我的代码中有Process Class,当我尝试从inputbuffer读取大量数据并且waitfor方法的进程类永远不会返回任何内容时,它无法读取inputbufferreader数据

  • 此问题发生在实时服务器
  • 但是代码运行正常,并从本地服务器的inputbuffer中读取所有数据

    private static JSONObject ExecJniApp(String inputJsonString) throws JniException
    {
    int exitStatus = 0;
    String workingDirectory = JniSettings.getJniAppDirectory();
    String command = workingDirectory + binaryName;
    System.out.println("ExecJniApp: inputJsonString: " + inputJsonString);
    String outputString = "";
    try
    {
        Process p = Runtime.getRuntime().exec(command, null, new File(workingDirectory));
        // send input vi stdin
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
        writer.write("\n>>>>>>>>>>");
        writer.write(inputJsonString);
        writer.write("<<<<<<<<<<\n");
        writer.flush();
        if (JniSettings.isLinux())
        {
            p.waitFor();
        }
        else
        {
            // System.out.println("ExecJniApp: windows wait for");
        }
        BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
        for (;;)
        {
            String line = reader.readLine();
            if (line == null)
            {
                break;
            }
            // System.out.println(line);
            outputString += line + "\n";
        }
        // exit code of command and log error detail
        // exit status = 0 -> Success
        exitStatus = p.exitValue();
        if (exitStatus != 0)
        {
            System.out.println("ExecJniApp: inputJsonString: " + inputJsonString);
            System.out.println("ExecJniApp: outputString:\n" + outputString);
            throw new Exception("Exit status other than zero :- " + exitStatus + "\noutput: ");
        }
    }
    catch (Exception e)
    {
        // System.out.println("ExecJniApp failed");
        e.printStackTrace();
        throw new JniException("JniInterface failed");
    }
    System.out.println("ExecJniApp: outputString:\n" + outputString);
    int index1 = outputString.indexOf(">>>>>>>>>>");
    if (index1 == -1)
    {
        // System.out.println("ExecJniApp failed, Invalid output format");
        throw new JniException("ExecJniApp failed, Invalid output format");
    }
    index1 += 10;
    int index2 = outputString.indexOf("<<<<<<<<<<");
    if (index2 == -1 || index2 <= index1)
    {
        // System.out.println("ExecJniApp failed, Invalid output format");
        throw new JniException("ExecJniApp failed, Invalid output format");
    }
    String outputJsonString = outputString.substring(index1, index2);
    // System.out.println("ExecJniApp: outputJsonString: " + outputJsonString);
    JSONParser parser = new JSONParser();
    JSONObject obj = null;
    try
    {
        obj = (JSONObject) parser.parse(outputJsonString);
    }
    catch (ParseException e)
    {
        // System.out.println("ExecJniApp failed, Json parse failed");
        e.printStackTrace();
        throw new JniException("JniInterface failed, Json parse failed");
    }
    Object errorObject = obj.get("error");
    if (errorObject != null)
    {
        String errorString = errorObject.toString();
        // System.out.println("ExecJniApp failed, " + errorString);
        throw new JniException("ExecJniApp failed, " + errorString);
    }
    return obj;
    }
    

1 个答案:

答案 0 :(得分:1)

只需使用以下代码替换您的代码即可 必须关闭InputStream连接。

 Process p = Runtime.getRuntime().exec(command, null, new File(workingDirectory));
// send input vi stdin
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
writer.write("\n>>>>>>>>>>");
writer.write(inputJsonString);
writer.write("<<<<<<<<<<\n");
writer.flush();

try{ 
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
for (;;)
{
    String line = reader.readLine();
    if (line == null)
    {
        break;
    }
    // System.out.println(line);
    outputString += line + "\n";
}
 p.getOutputStream().close();
 p.getInputStream().close();
}
catch(Exception e)
{
   e.printStackTrace();
}
if (JniSettings.isLinux())
{
    p.waitFor();
}
else
{
    // System.out.println("ExecJniApp: windows wait for");
}
// exit code of command and log error detail
// exit status = 0 -> Success
exitStatus = p.exitValue();
if (exitStatus != 0)
{
    System.out.println("ExecJniApp: inputJsonString: " + inputJsonString);
    System.out.println("ExecJniApp: outputString:\n" + outputString);
    throw new Exception("Exit status other than zero :- " + exitStatus + "\noutput: ");
}