java - 尝试使用 apache commons-exec jar 打开 cmd 时出错

Question

我正在尝试从 apache commons-exec 进行 mysql 转储，但出现以下错误

Exception in thread "main" java.io.IOException: Cannot run program "cmd.exe \c" (in directory "."): CreateProcess error=2, The system cannot find the file specified at java.lang.ProcessBuilder.start(ProcessBuilder.java:470) at java.lang.Runtime.exec(Runtime.java:593) at org.apache.commons.exec.launcher.Java13CommandLauncher.exec(Java13CommandLauncher.java:61) at org.apache.commons.exec.DefaultExecutor.launch(DefaultExecutor.java:279) at org.apache.commons.exec.DefaultExecutor.executeInternal(DefaultExecutor.java:336) at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:166) at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:153) at com.etq.e2mc.platform.windows.WindowsProcess.execCommons(WindowsProcess.java:87) at com.etq.e2mc.platform.windows.WindowsProcess.main(WindowsProcess.java:79) Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified at java.lang.ProcessImpl.create(Native Method) at java.lang.ProcessImpl.(ProcessImpl.java:177) at java.lang.ProcessImpl.start(ProcessImpl.java:28) at java.lang.ProcessBuilder.start(ProcessBuilder.java:452) ... 8 more

这是我正在使用的代码，它非常简单和直接，但我无法弄清楚为什么它不调用cmd(注意:尝试在没有cmd的情况下直接调用mysql转储，并且我得到相同类型的错误)，希望得到任何帮助

    public static void main(String[] args) throws Exception {
        execCommons();
    }

    public static void execCommons() throws ExecuteException, IOException {
        CommandLine cmd = new CommandLine("cmd.exe /c");
        cmd.addArguments("mysqldump");
        cmd.addArguments(new String[] { "-u", "root", " -P", "3316", " -h", "localhost", " -A", ">"});
        cmd.addArguments("\"G:\\test.sql \"" , false);
        new DefaultExecutor().execute(cmd);

    }

Answer 1

出于某种原因，commons-exec 似乎不喜欢在问题中使用命令措辞(使用 "cmd.exe/c" 初始化 CommandLine )，将其改写为以下内容后，一切似乎都正常工作

    public static void main(String[] args) throws Exception {
        execCommons();
    }

    public static void execCommons() throws ExecuteException, IOException {
        CommandLine cmd = new CommandLine("cmd.exe ");
        cmd.addArgument("/c");
        String command = "mysqldump " + "-u" + "root" + " -P" + "3316" + " -h" + "localhost" + " -A >" + "\"G:\\test.sql \"";
        cmd.addArgument(command,false);
        new DefaultExecutor().execute(cmd);    
    }

我不知道为什么它会这样工作，因为文档中没有说明，但我将其留在这里，以防它对某人有帮助。但如果有人有任何想法请告诉