使用apache的TelnetClient实现java向telnet服务器发送命令并显示数据（解决乱码问题）

package cn.keyidea.telnet;

import java.io.InputStream;
import java.io.PrintStream;

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

public class TelnetUtil {
private TelnetClient telnet = new TelnetClient("VT220");// telnet有VT100 VT52
// VT220 VTNT
// ANSI等协议。
private InputStream in;
private PrintStream out;
private static final String DEFAULT_AIX_PROMPT = "C:\\Users\\Administrator>";
// telnet 端口
private String port;
// 用户名
private String user;
// 密码
private String password;
// IP 地址
private String ip;
// 缺省端口
private static final int DEFAULT_TELNET_PORT = 23;

public TelnetUtil(String ip, String user, String password) {
this.ip = ip;
this.port = String.valueOf(TelnetUtil.DEFAULT_TELNET_PORT);
this.user = user;
this.password = password;
}

public TelnetUtil(String ip, String port, String user, String password) {
this.ip = ip;
this.port = port;
this.user = user;
this.password = password;
}

/**
* @return boolean 连接成功返回true，否则返回false
*/
private boolean connect() {
boolean isConnect = true;
try {
telnet.connect(ip, Integer.parseInt(port));
in = telnet.getInputStream();
out = new PrintStream(telnet.getOutputStream());
/** Log the user on* */
readUntil("login: ");
write(user);
readUntil("password: ");
write(password);
/** Advance to a prompt */
readUntil(DEFAULT_AIX_PROMPT);
} catch (Exception e) {
isConnect = false;
e.printStackTrace();
return isConnect;
}
return isConnect;
}

public void su(String user, String password) {
try {
write("su" + " - " + user);
readUntil("Password:");
write(password);
readUntil(DEFAULT_AIX_PROMPT);
} catch (Exception e) {
e.printStackTrace();
}
}

public String readUntil(String pattern) {
try {
char lastChar = pattern.charAt(pattern.length() - 1);
StringBuffer sb = new StringBuffer();
char ch = (char) in.read();
while (true) {
// System.out.print(ch);// ---需要注释掉
sb.append(ch);
if (ch == lastChar) {
if (sb.toString().endsWith(pattern)) {
// 处理编码，界面显示乱码问题
byte[] temp = sb.toString().getBytes("iso8859-1");
return new String(temp, "GBK");
}
}
ch = (char) in.read();
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

public void write(String value) {
try {
out.println(value);
out.flush();
// System.out.println(value);// ---需要注释掉
} catch (Exception e) {
e.printStackTrace();
}
}

public String sendCommand(String command) {
try {
write(command);
return readUntil(DEFAULT_AIX_PROMPT);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

private void disconnect() {
try {
telnet.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}

private String getIPConfig() {
this.connect();
String result = this.sendCommand("ipconfig");
this.disconnect();
// 去除命令提示符
return result.substring(0, result.indexOf(DEFAULT_AIX_PROMPT));
}

private String getDir() {
this.connect();
String result = this.sendCommand("dir");
this.disconnect();
// 去除命令提示符
return result.substring(0, result.indexOf(DEFAULT_AIX_PROMPT));
}

public static void main(String[] args) {
TelnetUtil telnet = new TelnetUtil("127.0.0.1", "administrator", "1");
System.out.println(telnet.getDir());
System.out.println(telnet.getIPConfig());
}

}