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java执行bat命令碰到的阻塞问题的解决方法
来源: 互联网 发布时间:2014-11-01
本文导语: 使用Java来执行bat命令,如果bat操作时间过长,有可能导致阻塞问题,而且不会执行bat直到关闭服务器。如: 代码如下:Runtime r=Runtime.getRuntime(); Process p=null; try{ String path = "D:/test.bat"; ...
使用Java来执行bat命令,如果bat操作时间过长,有可能导致阻塞问题,而且不会执行bat直到关闭服务器。
如:
代码如下:
Runtime r=Runtime.getRuntime();
Process p=null;
try{
String path = "D:/test.bat";
p = r.exec("cmd.exe /c "+path);
p.waitFor();
}catch(Exception e){
System.out.println("运行错误:"+e.getMessage());
e.printStackTrace();
}
一般java的exec是没有帮你处理线程阻塞问题的,需要手动处理。
处理后:
代码如下:
Runtime r=Runtime.getRuntime();
Process p=null;
try{
String path = "D:/test.bat";
p = r.exec("cmd.exe /c "+path);
StreamGobbler errorGobbler = new StreamGobbler(p.getErrorStream(), "ERROR");
errorGobbler.start();
StreamGobbler outGobbler = new StreamGobbler(p.getInputStream(), "STDOUT");
outGobbler.start();
p.waitFor();
}catch(Exception e){
System.out.println("运行错误:"+e.getMessage());
e.printStackTrace();
}
StreamGobbler 类如下:
代码如下:
package com.test.tool;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
/**
* 用于处理Runtime.getRuntime().exec产生的错误流及输出流
*/
public class StreamGobbler extends Thread {
InputStream is;
String type;
OutputStream os;
StreamGobbler(InputStream is, String type) {
this(is, type, null);
}
StreamGobbler(InputStream is, String type, OutputStream redirect) {
this.is = is;
this.type = type;
this.os = redirect;
}
public void run() {
InputStreamReader isr = null;
BufferedReader br = null;
PrintWriter pw = null;
try {
if (os != null)
pw = new PrintWriter(os);
isr = new InputStreamReader(is);
br = new BufferedReader(isr);
String line=null;
while ( (line = br.readLine()) != null) {
if (pw != null)
pw.println(line);
System.out.println(type + ">" + line);
}
if (pw != null)
pw.flush();
} catch (IOException ioe) {
ioe.printStackTrace();
} finally{
try {
pw.close();
br.close();
isr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
运行bat,就不会阻塞了。