java - 使用 Runtime.exec() 启动 Websphere 的 wsadmin.bat - 从进程的 InputStream 读取时挂起

Question

直接贴代码示例:

        Runtime rt = Runtime.getRuntime();
        path = "c:\IBM\WebSphere\AppServer\profiles\STSCDmgrProfile\bin\";
        cmd = path + "wsadmin";
        String cmdString = cmd
                + " -host "
                + host
                + " -port "
                + port
                + " -username "
                + username
                + " -password "
                + password
                + " "
                + "-f" + "c:/IBM/WebSphere/AppServer/profiles/STSCDMgrProfile/temp/mergedScripts.jy"
                + " -lang "
                + lang
                + " -tracefile logs/ssc_wsadmin_trace.txt -appendtrace true";
        _logger.finer(cmdString.replaceAll(" " + password, " <password>"));
        Process proc = rt.exec(cmdString);
        _logger.finer("Launched process");

        stdInput = new BufferedReader(new InputStreamReader(proc
                .getInputStream()));
        stdError = new BufferedReader(new InputStreamReader(proc
                .getErrorStream()));

        // read the output from the command
        String sIn = "";
        **while ((sIn = stdInput.readLine()) != null) {**
            _logger.log(Level.FINE, "runJCommand stin ==>", sIn);
        }

但是它在从 stdInput 执行 readLine() 时挂起。上面突出显示。以下是我在跟踪日志中看到的内容:

[7/30/13 23:48:04:937 GMT-12:00] 000000a6 ThreadMonitor W   WSVR0605W: Thread "WebContainer : 1" (00000175) has been active for 664085 milliseconds and may be hung.  There is/are 1 thread(s) in total in the server that may be hung.
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:223)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:267)
at java.io.BufferedInputStream.read(BufferedInputStream.java:328)
at sun.nio.cs.StreamDecoder$CharsetSD.readBytes(StreamDecoder.java:464)
at sun.nio.cs.StreamDecoder$CharsetSD.implRead(StreamDecoder.java:506)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:234)
at java.io.InputStreamReader.read(InputStreamReader.java:188)
at java.io.BufferedReader.fill(BufferedReader.java:147)
at java.io.BufferedReader.readLine(BufferedReader.java:310)
**at java.io.BufferedReader.readLine(BufferedReader.java:373)**
at com.ibm.sametime.console.admin.plugins.wsadmin.SSCWsAdmin.runJCommand(SSCWsAdmin.java:924)

如果我通过命令行手动运行相同的 mergedScripts.jy(我在上面的 java 代码中调用)，那么它会成功执行并在几分钟内完成。然而，通过 Java 代码，它永远运行。

可能的原因是什么？在上述情况下，STDIN 究竟是什么？

Answer 1

在您的示例代码中，您正在从 InputStream 读取，但根本不是从 ErrorStream 读取，您的问题可能是 ErrorStream 的缓冲区已满，这导致进程阻塞或死锁。请参阅“为什么 Runtime.exec() 挂起”部分 in this article .文章继续描述如何避免这种情况，但您可以使用 ProcessBuilder 来简化过程。而不是 Runtime.exec() 然后重定向 ErrorStream。

ProcessBuilder pb = new ProcessBuilder("wsadmin", "-host", host, "-port", port, "-username", username, ... );
Process proc = pb.redirectErrorStream(true).start();
//Read from the InputStread as you were...

What actually is STDIN in the above case ?

proc.getInputStream() 将包含从命令行运行 wsadmin 命令时产生的任何输出。