java中执行cmd

如何在java中执行cmd命令呢，下面是示例代码：

 

	private void executeCmdText(String cmdText) {
		try {
			
			Runtime rt = Runtime.getRuntime();
			Process process = rt.exec(cmdText);
			
			readInputStream(process.getErrorStream());
			readInputStream(process.getInputStream());
			
			int exitVal = process.waitFor();
			System.out.println("Process exitValue: " + exitVal);
			
		} catch(Exception ex) {
			ex.printStackTrace();
		}
	}
	
	private void readInputStream(InputStream is) throws IOException {
		
		InputStreamReader isr = new InputStreamReader(is);
		BufferedReader br = new BufferedReader(isr);
		
		String line = null;
		while((line = br.readLine()) != null) {
			System.out.println(line);
		}
	}

 

这里要注意的是：

      永远要在调用waitFor方法之前读取数据流。

      永远要先从标准错误流读取，再从标准输出流读取。（cmd的标准输出流就是java的标准输入流process.getInputStream()）