java中用Process执行外部命令挂起问题的解决办法
我要在Java中调一个外部命令，于是写了以下代码Process p = Runtime.getRuntime().exec("my command ...");int c = p.waitFor();if (c != 0){ System.out.prinln("处理失败"); BufferedReader br = new BufferedReader(new InputStreamReader(p.getErrorStream())); for (String line = br.readLine(); line != null; line = br.readLine()) { System.out.println(line); } }
当执行的外部命令没有任何输出的时候，这段代码运行正常，但如果执行的外部命令有输出的时候，这段程序就会挂起，估计是因为流没有被读取导致了堵塞，于是把代码改为
public void test() throws IOException, InterruptedException { Process p = Runtime.getRuntime().exec("command..."); String errorMsg = readInputStream(p.getErrorStream()); String outputMsg = readInputStream(p.getInputStream()); int c = p.waitFor(); if (c != 0) { System.out.println("处理失败：" + errorMsg); }else {//print command output System.out.println(outputMsg); } } privateString readInputStream(InputStream is) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(is)); StringBuffer lines = new StringBuffer(); for (String line = br.readLine(); line != null; line = br.readLine()) { lines.append(line); } return lines.toString(); }
一切正常。
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