在网上常见的用Java调用外部命令返回结果的方法是: process =runtime.exec(cmd) is = process.getInputStream(); isr=new InputStreamReader(is); br =new BufferedReader(isr); while( (line = br.readLine()) != null ) { out.println(line); out.flush(); } 这种方法在遇到像cvs checkout modules这样不能马上返回结果的命令来说是无效的,不仅得不到返回结果,进程也会终止。其原因是,process在没有来得及gegtInputStream是,调用了BufferedReader.readLine其返回结果是null,也就是说循环一开始就会停止。因此想要正常运行只能直接读取process.getInputStream(),如下: import java.io.*; /** * * @author tyrone * */ public class CMDExecute { /** * @param cmd * @return * @throws IOException */ public synchronized String run(String[] cmd,String workdirectory) throws IOException{ String line=null; String result=""; try { ProcessBuilder builder = new ProcessBuilder(cmd); //set working directory if (workdirectory!=null) builder.directory(new File(workdirectory)); builder.redirectErrorStream(true); Process process = builder.start(); InputStream in=process.getInputStream(); byte[] re=new byte[1024]; while (in.read(re)!= -1) { System.out.println(new String(re)); result = result + new String(re); } in.close(); } catch (Exception ex) { ex.printStackTrace(); } return result; } /** * @param args=cvs log */ public static void main(String[] args){ String result=null; CMDExecute cmdexe=new CMDExecute(); try { result= cmdexe.run(args,"D:\\MyProject\\colimas\\axis_c"); System.out.println(result); }catch ( IOException ex ){ ex.printStackTrace(); } } } 经过测试,本方法可以运行返回大量结果的应用程序。 |