Java调用Telnet示例

import java.io.IOException;

import java.io.InputStream;

import java.io.PrintStream;

import java.io.UnsupportedEncodingException;



import org.apache.commons.net.telnet.TelnetClient;



/**

 * Telnet操作器,基于commons-net-2.2.jar

 * @author JiangKunpeng

 *

 */

public class TelnetOperator {

	

	private String prompt = ">";	//结束标识字符串,Windows中是>,Linux中是#

	private char promptChar = '>';	//结束标识字符

	private TelnetClient telnet;

	private InputStream in;		// 输入流,接收返回信息

	private PrintStream out;	// 向服务器写入 命令

	

	/**

	 * @param termtype	协议类型：VT100、VT52、VT220、VTNT、ANSI

	 * @param prompt	结果结束标识

	 */

	public TelnetOperator(String termtype,String prompt){

		telnet = new TelnetClient(termtype);

		setPrompt(prompt);

	}

	

	public TelnetOperator(String termtype){

		telnet = new TelnetClient(termtype);

	}

	

	public TelnetOperator(){

		telnet = new TelnetClient();

	}

	

	/**

	 * 登录到目标主机

	 * @param ip

	 * @param port

	 * @param username

	 * @param password

	 */

	public void login(String ip, int port, String username, String password){

		try {

			telnet.connect(ip, port);

			in = telnet.getInputStream();

			out = new PrintStream(telnet.getOutputStream());

			readUntil("login:");

			write(username);

			readUntil("password:");

			write(password);

			String rs = readUntil(null);

			if(rs!=null&&rs.contains("Login Failed")){

				throw new RuntimeException("登录失败");

			}

		} catch (Exception e) {

			throw new RuntimeException(e);

		}

	}

	

	/**

	 * 读取分析结果

	 * 

	 * @param pattern	匹配到该字符串时返回结果

	 * @return

	 */

	public String readUntil(String pattern) {

		StringBuffer sb = new StringBuffer();

		try {

			char lastChar = (char)-1;

			boolean flag = pattern!=null&&pattern.length()>0;

			if(flag)

				lastChar = pattern.charAt(pattern.length() - 1);

			char ch;

			int code = -1;

			while ((code = in.read()) != -1) {

				ch = (char)code;

				sb.append(ch);

				

				//匹配到结束标识时返回结果

				if (flag) {

					if (ch == lastChar && sb.toString().endsWith(pattern)) {

						return sb.toString();

					}

				}else{

					//如果没指定结束标识,匹配到默认结束标识字符时返回结果

					if(ch == promptChar)

						return sb.toString();

				}

				//登录失败时返回结果

				if(sb.toString().contains("Login Failed")){

					return sb.toString();

				}

			}

		} catch (Exception e) {

			e.printStackTrace();

		}

		return sb.toString();

	}

	

	/**

	 * 发送命令

	 * 

	 * @param value

	 */

	public void write(String value) {

		try {

			out.println(value);

			out.flush();

		} catch (Exception e) {

			e.printStackTrace();

		}

	}

	

	/**

	 * 发送命令,返回执行结果

	 * 

	 * @param command

	 * @return

	 */

	public String sendCommand(String command) {

		try {

			write(command);

			return readUntil(prompt);

		} catch (Exception e) {

			e.printStackTrace();

		}

		return null;

	}

	

	/**

	 * 关闭连接

	 */

	public void distinct(){

		try {

			if(telnet!=null&&!telnet.isConnected())

				telnet.disconnect();

		} catch (IOException e) {

			e.printStackTrace();

		}

	}



	public void setPrompt(String prompt) {

		if(prompt!=null){

			this.prompt = prompt;

			this.promptChar = prompt.charAt(prompt.length()-1);

		}

	}

	

	public static void main(String[] args) {

		TelnetOperator telnet = new TelnetOperator("VT220",">");	//Windows,用VT220,否则会乱码

		telnet.login("192.168.2.19", 23, "administrator", "123456");

		String rs = telnet.sendCommand("ipconfig");

		try {

			rs = new String(rs.getBytes("ISO-8859-1"),"GBK");	//转一下编码

		} catch (UnsupportedEncodingException e) {

			e.printStackTrace();

		}

		System.out.println(rs);

	}

	

}