Java调用批处理文件(.bat)

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原文点这里
java在执行.bat文件时,经常会出现卡住不动的情况,我们称之为阻塞.
发生阻塞的原因是,在使用Runtime.getRuntime.exec(“xx:/xxxx.bat”)时,会有outputStream,ErrStream,InputStream三个IO流,如果这三个IO流都有数据的传输操作,那么必须对每一个IO流进行处理,如果有一个IO流漏处理了,那么程序将无限期的等待该IO流被处理,继而程序阻塞.
下面,已java打开安装apache2.2的.bat文件为例,说明一下如何处理阻塞.

public class TestApache {      public static void main(String[] args) {          try {              final CountDownLatch threadSignal = new CountDownLatch(2);//初始化countDown              System.out.println("Start ......");              final Process pro = Runtime.getRuntime().exec("cmd /c \"c:\\start.bat\"");              pro.getOutputStream().close();              Runnable errThread = new Runnable() {                  @Override                  public void run() {                      try {                          InputStream is = pro.getErrorStream();                          InputStreamReader isr = new InputStreamReader(is);                          BufferedReader br = new BufferedReader(isr);                          String line = "";                          StringBuilder sb = new StringBuilder();                          while((line = br.readLine()) != null) {                              sb.append(line);                          }                          System.out.println("error : " + sb.toString());                      } catch (IOException e) {                          e.printStackTrace();                      }                      threadSignal.countDown();//线程结束时计数器减1                   }              };              new Thread(errThread).start();              Runnable inputThread = new Runnable() {                  @Override                  public void run() {                      try {                          InputStream is = pro.getInputStream();                          InputStreamReader isr = new InputStreamReader(is);                          BufferedReader br = new BufferedReader(isr);                          String line = "";                          StringBuilder sb = new StringBuilder();                          while((line = br.readLine()) != null) {                              sb.append(line);                          }                          System.out.println("input : " + sb.toString());                          is.close();                          isr.close();                          br.close();                      } catch (IOException e) {                          e.printStackTrace();                      }                      threadSignal.countDown();//线程结束时计数器减1                   }              };              new Thread(inputThread).start();              try {                  threadSignal.await();              } catch (InterruptedException e) {                  e.printStackTrace();              }              System.out.println("=========================");              Runtime.getRuntime().exec("cmd /c net start apache2.2");              System.out.println("cmd /c net start apache2.2");          } catch (IOException e) {              e.printStackTrace();          }      }  }

关于OutputStream,程序用不到,直接在开始的时候就应该close掉.对于errStream & inputStream应该分别用一个线程来读取出IO流中的内容.
注意:必须使用线程,否则依然会阻塞.

final CountDownLatch threadSignal = new CountDownLatch(2);//初始化countDown
这一个栏位是用来让主线程等待两个子线程执行完毕用的.

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