如何将字符串参数传递给使用Apache Commons Exec启动的可执行文件？ [英] How to pipe a string argument to an executable launched with Apache Commons Exec?

问题描述

我需要将一个文本参数传递给使用Apache Commons Exec启动的命令的stdin（对于好奇，命令是gpg，参数是密钥库的密码; gpg没有提供密码的参数明确地，只从stdin接受它。）

I need to pipe a text argument to the stdin of a command launched with Apache Commons Exec (for the curious, the command is gpg and the argument is the passphrase to the keystore; gpg does not have an argument to provide the passphrase explicitly, only to accept it from stdin).

此外，我需要它来支持Linux和Windows。

In addition, I need this to support both Linux and Windows.

在shell脚本中我会做

In a shell script I'd do

cat mypassphrase|gpg --passphrase-fd

或

type mypassphrase|gpg --passphrase-fd

但是类型在Windows上不起作用，因为它不是可执行文件但是命令中内置的命令（cmd.exe）。

but type doesn't work on Windows as it's not an executable but a command built into the command interpreted (cmd.exe).

代码无效（由于上述原因）如下所示。为此产生一个完整的外壳太难看了，我一直在寻找更优雅的解决方案。不幸的是，BouncyCastle库和PGP之间存在一些不兼容问题，因此我无法在（非常短的）时间内使用完全编程的解决方案。

The code not working (for the above reason) is below. To spawn an entire shell for this is too ugly, I was looking for a more elegant solution. Unfortunately, there are some incompatibility problems between the BouncyCastle library and PGP so I cannot use a fully programmatic solution in the (very short) time I have.

提前致谢。

CommandLine cmdLine = new CommandLine("type");
cmdLine.addArgument(passphrase);
cmdLine.addArgument("|");
cmdLine.addArgument("gpg");
cmdLine.addArgument("--passphrase-fd");
cmdLine.addArgument("0");
cmdLine.addArgument("--no-default-keyring");
cmdLine.addArgument("--keyring");
cmdLine.addArgument("${publicRingPath}");
cmdLine.addArgument("--secret-keyring");
cmdLine.addArgument("${secretRingPath}");
cmdLine.addArgument("--sign");
cmdLine.addArgument("--encrypt");
cmdLine.addArgument("-r");
cmdLine.addArgument("recipientName");
cmdLine.setSubstitutionMap(map);
DefaultExecutor executor = new DefaultExecutor();
int exitValue = executor.execute(cmdLine);

推荐答案

您无法添加管道参数（ | ）因为 gpg 命令不会接受。它是shell（例如 bash ）解释管道并在你将命令行输入shell时进行特殊处理。

You cannot add a pipe argument (|) because the gpg command won't accept that. It's the shell (e.g. bash) that interprets the pipe and does special processing when you type that commandline into the shell.

您可以使用 ByteArrayInputStream 手动将数据发送到命令的标准输入（很像 bash 当它执行时看到 | ）。

You can use ByteArrayInputStream to manually send data to the standard input of a command (much like bash does when it sees the |).

    Executor exec = new DefaultExecutor();

    CommandLine cl = new CommandLine("sed");
            cl.addArgument("s/hello/goodbye/");

    String text = "hello";
    ByteArrayInputStream input =
        new ByteArrayInputStream(text.getBytes("ISO-8859-1"));
    ByteArrayOutputStream output = new ByteArrayOutputStream();

    exec.setStreamHandler(new PumpStreamHandler(output, null, input));
    exec.execute(cl);

    System.out.println("result: " + output.toString("ISO-8859-1"));

这应该相当于输入 echohello| sed s / hello / goodbye / 进入（ bash ）shell（尽管UTF-8可能是更合适的编码）。

This should be the equivalent of typing echo "hello" | sed s/hello/goodbye/ into a (bash) shell (though UTF-8 may be a more appropriate encoding).

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