从Java运行Echo(running Echo from Java)

 我正在尝试Runtime.exec（）方法来运行命令行进程。 
 
 我编写了这个示例代码，它运行时没有问题，但不会在c：\ tmp.txt中生成文件。 
 
String cmdLine = "echo foo > c:\\tmp.txt";
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(cmdLine);

BufferedReader input = new BufferedReader(
                           new InputStreamReader(pr.getInputStream()));
String line;

StringBuilder output = new StringBuilder();
while ((line = input.readLine()) != null) {
    output.append(line);
}

int exitVal = pr.waitFor();

logger.info(String.format("Ran command '%s', got exit code %d, output:\n%s", cmdLine, exitVal, output));
 
 输出是 
 
 
 
 INFO 21-04 20：02：03,024 - Ran命令'echo foo> c：\ tmp.txt'，退出代码0，输出：foo> c：\ tmp.txt 
 

I'm trying out the Runtime.exec() method to run a command line process.
 
I wrote this sample code, which runs without problems but doesn't produce a file at c:\tmp.txt.
 
String cmdLine = "echo foo > c:\\tmp.txt";
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(cmdLine);

BufferedReader input = new BufferedReader(
                           new InputStreamReader(pr.getInputStream()));
String line;

StringBuilder output = new StringBuilder();
while ((line = input.readLine()) != null) {
    output.append(line);
}

int exitVal = pr.waitFor();

logger.info(String.format("Ran command '%s', got exit code %d, output:\n%s", cmdLine, exitVal, output));
 
The output is 
 
 
 
INFO 21-04 20:02:03,024 - Ran command 'echo foo > c:\tmp.txt', got exit code 0, output: foo > c:\tmp.txt
 

原文：https://stackoverflow.com/questions/2684985