Java调用shell脚本阻塞

  Java在调用Shell时，要不断读取进程中标准输出和错误输出流的信息，否则缓冲区被写满就会造成子进程阻塞而无法继续运行下去，可起两个线程不断读取标准输出、错误流信息而不被阻塞，如下代码所示

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
 
import org.apache.commons.io.IOUtils;
 
import ch.ethz.ssh2.ChannelCondition;
import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
 
 
public class RmtShellExecutor {
 
     
    private Connection conn;
    private String ip;
    private String usr;
    private String psword;
    private String charset = Charset.defaultCharset().toString();
 
    private static final int TIME_OUT = 1000 * 5 * 60;
 
    public RmtShellExecutor(String ip, String usr, String ps) {
        this.ip = ip;
        this.usr = usr;
        this.psword = ps;
    }
 
    private boolean login() throws IOException {
        conn = new Connection(ip);
        conn.connect();
        return conn.authenticateWithPassword(usr, psword);
    }
 
    //本地执行方法
    public static void execLocal(String cmd) {
           try {
                Process proc = Runtime.getRuntime().exec(cmd);
                StreamGobbler errorGobbler = new StreamGobbler(proc.getErrorStream(), "ERROR");
                StreamGobbler outputGobbler = new StreamGobbler(proc.getInputStream(), "OUTPUT");
                errorGobbler.start();
                outputGobbler.start();
                int exitVal = proc.waitFor();
                System.out.println("ExitValue: " + exitVal);
             } catch (Exception e) {
                  e.printStackTrace();
             } 
             
        }
         
    //远程执行方法
    public int execRemote(String cmds){
        InputStream stdOut = null;
        InputStream stdErr = null;
        int ret = -1;
        try {
            if (login()) {
                // Open a new {@link Session} on this connection
                Session session = conn.openSession();
                // Execute a command on the remote machine.
                session.execCommand(cmds);
 
                GobblerThread gtOut = new GobblerThread(session.getStdout(),"STD_OUT");
                GobblerThread gtErr = new GobblerThread(session.getStderr(),"STD_ERR");
                gtOut.start();
                gtErr.start();
 
                session.waitForCondition(ChannelCondition.EXIT_STATUS, TIME_OUT);
                ret = session.getExitStatus();
            } else {
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        finally {
            if (conn != null) {
                conn.close();
            }
            IOUtils.closeQuietly(stdOut);
            IOUtils.closeQuietly(stdErr);
        }
        return ret;
    }
 
    public static void main(String args[]) throws Exception {
        RmtShellExecutor exe = new RmtShellExecutor("192.168.3.5", "test",
                "123456");
        System.out.println(exe.execRemote("sh /home/test/cmd.sh company=32"));
    }
}
 
class GobblerThread extends Thread
{
    InputStream is;
    String type;
     
    GobblerThread(InputStream is, String type)
    {
        this.is = is;
        this.type = type;
    }
     
    public void run()
    {
        try
        {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line=null;
            while ( (line = br.readLine()) != null)
                System.out.println(line);    
            } catch (IOException e)
              {
                e.printStackTrace();  
              }
    }
}

其中execLocal 为本地调用cmd的方法

  exeRemote 可利用ssh登录远程机器调用cmd的方法