java - 在 JNA 中重定向输出并静默生成子进程(无弹出命令窗口)

Question

我已经编写了一个 java 程序来生成子 java 进程。当它产生子进程时，它会打开一个命令提示符窗口，并将输出重定向到命令提示符。你能告诉我如何在没有额外命令窗口的情况下生成/创建子进程并将这个进程的输出重定向到一个文件。我正在使用 Java 6 和 JNA 3.5.2

下面是创建进程的命令

cmd = "c:\\jdk1.6.0_30\\bin\\java.exe -Xmx256m -Xss1024k  -cp <classpath jars>; 
-Dorg.omg.CORBA.ORBClass=org.jacorb.orb.ORB com.xyz.test.MainProgram <program arguments>

带有弹出命令提示符的工作代码

private boolean createChildProcess(ProcessData processData,String cmd,String appName){
HANDLEByReference childStdInRead = new HANDLEByReference();
HANDLEByReference childStdOutWrite = new HANDLEByReference();

    int STARTF_USESTDHANDLES = 0x00000100;

    WinBase.PROCESS_INFORMATION.ByReference processInformation = new WinBase.PROCESS_INFORMATION.ByReference();
    STARTUPINFO startupInfo = new STARTUPINFO();

    // Create the child process. 
    if (!Kernel32.INSTANCE.CreateProcess(
            null, 
            cmd, 
            null, 
            null, 
            true, 
            new DWORD(0x00000020), //new DWORD(0x00000001)
            null, 
            null, 
            startupInfo, 
            processInformation)){
        System.err.println(Kernel32Util.formatMessageFromLastErrorCode(Kernel32.INSTANCE.GetLastError()));
        return false;

    }else {
        System.out.println("Created Process :"+processInformation.dwProcessId.intValue());
        processData.setProcessId(processInformation.dwProcessId.intValue());
        //processData.sethProcess(processInformation.hProcess);
        //com.sun.jna.platform.win32.Kernel32.INSTANCE.WaitForSingleObject(processInformation.hProcess, 0xFFFFFFFF);
        com.sun.jna.platform.win32.Kernel32.INSTANCE.CloseHandle(processInformation.hProcess);
        com.sun.jna.platform.win32.Kernel32.INSTANCE.CloseHandle(processInformation.hThread);
        return true;
    }
} </pre>

我尝试了以下代码，但没有用

private boolean createChildProcess(ProcessData processData,String cmd,String appName){

    //Tried with Output to file
    HANDLEByReference childStdInRead = new HANDLEByReference();
    HANDLEByReference childStdInWrite = new HANDLEByReference();
    HANDLEByReference childStdOutRead = new HANDLEByReference();
    HANDLEByReference childStdOutWrite = new HANDLEByReference();

    int STARTF_USESTDHANDLES = 0x00000100;

    WinBase.PROCESS_INFORMATION.ByReference processInformation = new WinBase.PROCESS_INFORMATION.ByReference();
    STARTUPINFO startupInfo = new STARTUPINFO();
    startupInfo.cb = new DWORD(processInformation.size());
    startupInfo.hStdError = childStdOutWrite.getValue();
    startupInfo.hStdOutput = childStdOutWrite.getValue();
    startupInfo.hStdInput = childStdInRead.getValue();
    startupInfo.dwFlags |= STARTF_USESTDHANDLES;

    SECURITY_ATTRIBUTES saAttr = new SECURITY_ATTRIBUTES();
    saAttr.dwLength = new DWORD(saAttr.size());
    saAttr.bInheritHandle = true;
    saAttr.lpSecurityDescriptor = null;

    // Create a pipe for the child process's STDOUT. 
    if (!com.sun.jna.platform.win32.Kernel32.INSTANCE.CreatePipe(childStdOutRead, childStdOutWrite, saAttr, 0)){
        System.err.println(Kernel32.INSTANCE.GetLastError());
    }

    // Ensure the read handle to the pipe for STDOUT is not inherited.
    if (!com.sun.jna.platform.win32.Kernel32.INSTANCE.SetHandleInformation(childStdOutRead.getValue(), HANDLE_FLAG_INHERIT, 0)){
        System.err.println(Kernel32.INSTANCE.GetLastError());;
    }

    // Create the child process. 
    if (!Kernel32.INSTANCE.CreateProcess(
            null, 
            cmd, 
            null, 
            null, 
            true, 
            new DWORD(0x00000020), //new DWORD(0x00000001)
            null, 
            null, 
            startupInfo, 
            processInformation)){
        System.err.println(Kernel32Util.formatMessageFromLastErrorCode(Kernel32.INSTANCE.GetLastError()));
        return false;

    }else {
        System.out.println("Created Process :"+processInformation.dwProcessId.intValue());
        processData.setProcessId(processInformation.dwProcessId.intValue());
        //processData.sethProcess(processInformation.hProcess);
        //com.sun.jna.platform.win32.Kernel32.INSTANCE.WaitForSingleObject(processInformation.hProcess, 0xFFFFFFFF);

        HANDLE inputFile = com.sun.jna.platform.win32.Kernel32.INSTANCE.CreateFile(
                "c:\\"+processInformation.dwProcessId.intValue()+".txt", 
                GENERIC_READ, 
                0, 
                null, 
                OPEN_EXISTING, 
                FILE_ATTRIBUTE_READONLY, 
                null);
        //ReadFromPipe(childStdOutRead,childStdOutWrite);
        com.sun.jna.platform.win32.Kernel32.INSTANCE.CloseHandle(processInformation.hProcess);
        com.sun.jna.platform.win32.Kernel32.INSTANCE.CloseHandle(processInformation.hThread);
        return true;
    }
}

Answer 1

在 Windows 上，调用 javaw.exe而不是 java.exe .这将避免“控制台”窗口。

至于重定向到文件，最简单的方法可能是将参数传递给 Java 子进程以指示所需的文件，然后重定向 System.out和 System.err写入该文件。
System.out和 System.err是 PrintStream s，因此在启动时，您可以简单地创建自己的(映射到 FileOutputStream )以重定向所有控制台输出。见 this question on SO详情。