关于telnet协议的研究以及用java进行封装实现自己的telnet客户端
最近在做一个远程控制的模块，其中用到了telnet协议，开始用的是apache-net包的telnetclient，但发现问题不少，比较慢，还有就是判断是否read完毕的问题。后来经过讨论打算实现自己的telnet，于是网址打罗了一番，找了一个，但是bug也不少，就开始封装。具体的telnet我已经发过2篇文章了，这里再发布一个深化封装的telnet实现。
仅供参考，可以在windows和linux上运行。
package baby.net.base;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.ArrayList;
import org.apache.log4j.Logger;
/**
* telnet 基本连接类
*
* @description
* @author weichaofan
* @date 2013年10月25日
*/
public class TelnetBase {
private static final byte SB = (byte) 250;// 子选项开始
private static final byte SE = (byte) 240;// 子选项结束
private static final byte WILL = (byte) 251;// 选项协商
private static final byte WONT = (byte) 252;// 选项协商
private static final byte DO = (byte) 253;// 选项协商
private static final byte DONT = (byte) 254;// 选项协商
private static final byte IAC = (byte) 255;// 数据字节255
private static final byte ECHO = (byte) 1;// 回显
private static final byte IS = (byte) 0;// 是
private static final byte SUPPRESS = (byte) 3;// 抑制继续进行
private static final byte TT = (byte) 24;// 终端类型
private InputStream is;
private OutputStream os;
private Socket client;
private byte[] readBuffer = new byte[20 * 1024];
private int miniReadIntervalMillSec = 3000;// 最短read阻塞间隔时间-毫秒
private int connectTimeout = 1000;// 连接超时时间
private int maxReadTimeout = 5000;
public static String[] failTags = { "Failed", "fail", "incorrect" };
public static String[] loginTags = { "$", "#", ">", "ogin", "@" };
public static String[] commondEndTags= { "$", "#", ">"};
public static String[] allTags = { "Failed", "fail", "incorrect", "$", "#",
">", "ogin", "@" };
private String ip;
private int port = 23;
Logger logger = Logger.getLogger(getClass());
/**
*
* 打开telnet连接
*
* @param ip
* @param port
* 23
*
* @return
*
* @throws CmdException
*/
public TelnetBase(String ip) {
this(ip, 23);
}
/**
*
* 打开telnet连接
*
* @param ip
* @param port
* @return
* @throws CmdException
*/
public TelnetBase(String ip, int port) {
this.ip = ip;
this.port = port;
}
/**
* 连接
*
* @return
* @throws Exception
*/
public String connect() throws Exception {
try {
client = new Socket();
client.connect(new InetSocketAddress(ip, port), connectTimeout);
client.setSoTimeout(miniReadIntervalMillSec);// 设置is的read方法阻塞时间
is = client.getInputStream();
os = client.getOutputStream();
} catch (Exception e) {
this.close();
throw new Exception(e);
}
return readKeyWords("ogin:");
}
/**
*
* 读取回显，并进行telnet协商
*
* @return
*
* @throws IOException
*/
public String recieveEcho() throws IOException {
int len = is.read(this.readBuffer);
ArrayList<Byte> bsList = new ArrayList<Byte>();
ArrayList<Byte> cmdList = new ArrayList<Byte>();
for (int i = 0; i < len; i++) {
int b = this.readBuffer[i] & 0xff;// &0xff是为了防止byte的255溢出,java中byte的取值是-128~127
if (b != 255) {
if (b == '\n' || b == '\0') {// NVT中行结束符以'\r\n'表示，回车以'\r\0表示'
continue;
}
bsList.add((byte) b);
continue;
}
cmdList.add(IAC);
switch (this.readBuffer[++i] & 0xff) {
case 251:// 服务器想激活某选项
if ((readBuffer[++i] & 0xff) == 1) {// 同意回显
cmdList.add(DO);
cmdList.add(ECHO);
} else if ((readBuffer[i] & 0xff) == 3) {// 同意抑制继续执行
cmdList.add(DO);
cmdList.add(SUPPRESS);
// cmdList.add(GA);
} else {// 不同意其他类型协商
cmdList.add(DONT);
cmdList.add(readBuffer[i]);
}
break;
case 253:// 服务器想让客户端发起激活某选项
if ((readBuffer[++i] & 0xff) == 24) {// 终端类型
cmdList.add(WONT);// 同意激活终端类型协商
cmdList.add(TT);
} else if ((readBuffer[i] & 0xff) == 1) {
cmdList.add(WILL);
cmdList.add(ECHO);
} else {
cmdList.add(WONT);// 不同意其他类型协商
cmdList.add(readBuffer[i]);
}
break;
case 250:// 子选项开始
cmdList.add(SB);
if ((readBuffer[++i] & 0xff) == 24
&& (readBuffer[++i] & 0xff) == 1) {// 发送你的终端类型
cmdList.add(TT);
cmdList.add(IS);// 我的终端类型是
cmdList.add((byte) 'V');
cmdList.add((byte) 'T');
cmdList.add((byte) '1');
cmdList.add((byte) '0');
cmdList.add((byte) '0');
}
break;
case 240:// 子选项结束
cmdList.add(SE);
break;
case 252:// 必须同意
cmdList.add(DONT);
cmdList.add(readBuffer[++i]);
break;
case 254:// 必须同意
cmdList.add(WONT);
cmdList.add(readBuffer[++i]);
break;
}
}
// 如果有协商则向服务端发送协商选项
if (cmdList.size() > 0) {
byte[] writeBuffer = new byte[cmdList.size()];
for (int i = 0; i < cmdList.size(); i++) {
writeBuffer[i] = cmdList.get(i);
}
os.write(writeBuffer);
}
// 组织回显字符
int size = bsList.size();
String str = "";
if (size > 0) {
byte[] bs = new byte[size];
for (int i = 0; i < size; i++) {
bs[i] = bsList.get(i).byteValue();
}
str = new String(bs, "gbk");
} else {
// 如果是协商，则回传协商信息
if (cmdList.size() > 0) {
str = recieveEcho();
}
}
// log(len, cmdList);
return str;
}
private void log(int len, ArrayList<Byte> cmdList) {
logger.debug("read===== ");
for (int i = 0; i < len; i++) {
logger.debug(readBuffer[i] & 0xff);
logger.debug(" ");
}
if (cmdList.size() > 0) {
logger.debug("write==== ");
for (int i = 0; i < cmdList.size(); i++) {
logger.debug(cmdList.get(i) & 0xff);
logger.debug(" ");
}
}
}
/**
* 用户名 命令中不要包括回车、换行
*
* @param cmd
* @param keyWords
* @return
*/
public String sendUserName(String name) throws Exception {
name += "\r\n";
os.write(name.getBytes());
return readKeyWords("assword");
}
/**
* 密码 命令中不要包括回车、换行
*
* @param cmd
* @param keyWords
* @return
*/
public String sendUserPwd(String pwd) throws Exception {
pwd += "\r\n";
os.write(pwd.getBytes());
return readKeyWords(allTags);
}
/**
* 命令中不要包括回车、换行
*
* @param cmd
* @param keyWords
* @return
*/
public String sendCmd(String cmd, String... keyWords) throws Exception {
return sendCmd(cmd,false,keyWords);
}
/**
* 命令中不要包括回车、换行
*
* @param cmd
* @param keyWords
* @return
*/
public String sendCmd(String cmd,boolean excludeCommandCheck, String... keyWords) throws Exception {
os.write((cmd + "\r\n").getBytes());
if(!excludeCommandCheck){
return readKeyWords(cmd,maxReadTimeout,keyWords);
}else{
return readKeyWords(keyWords);
}
}
/**
* 命令中不要包括回车、换行 默认搜索条件为$、#、>
* 不包含执行命令中的关键字
* @param cmd
* @param keyWords
* @return
*/
public String sendCommand(String cmd) throws Exception {
return sendCommand(cmd,false);
}
/**
* 命令中不要包括回车、换行 默认搜索条件为$、#、>
* 是否包含执行命令中的关键字
* @param cmd
* @param keyWords
* @return
*/
public String sendCommand(String cmd,boolean excludeCommandCheck) throws Exception {
os.write((cmd + "\r\n").getBytes());
if(!excludeCommandCheck){
return readKeyWords(cmd,maxReadTimeout,commondEndTags);
}else{
return readKeyWords(commondEndTags);
}
}
/**
* 命令中不要包括回车、换行 默认搜索条件为$、#、>
* 不包含执行命令中的关键字
* @param cmd
* @param timeOut
* @param keyWords
* @return
*/
public String sendCommand(String cmd, long timeOut) throws Exception {
return sendCommand(cmd,timeOut, false);
}
/**
* 命令中不要包括回车、换行 默认搜索条件为$、#、>
* 是否包含执行命令中的关键字
* @param cmd
* @param timeOut
* @param keyWords
* @return
*/
public String sendCommand(String cmd, long timeOut,boolean excludeCommandCheck) throws Exception {
os.write((cmd + "\r\n").getBytes());
if(!excludeCommandCheck){
return readKeyWords(cmd,timeOut, commondEndTags);
}else{
return readKeyWords(timeOut, commondEndTags);
}
}
/**
* 命令中不要包括回车、换行
*
* @param cmd
* @param timeOut
* @param keyWords
* @return
*/
public String sendCmd(String cmd, long timeOut, String... keyWords)
throws Exception {
return sendCmd(cmd,false,timeOut, keyWords);
}
/**
* 命令中不要包括回车、换行
*
* @param cmd
* @param timeOut
* @param keyWords
* @return
*/
public String sendCmd(String cmd, boolean excludeCommandCheck,long timeOut, String... keyWords)
throws Exception {
os.write((cmd + "\r\n").getBytes());
if(!excludeCommandCheck){
return readKeyWords(cmd,timeOut, keyWords);
}else{
return readKeyWords(timeOut, keyWords);
}
}
/**
*
* 关闭telnet连接
*/
public void close() {
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (os != null) {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (client != null) {
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
*
* 读取期望值，使用默认超时时间5秒
*
* @param keyWords
*
* @return
*/
public String readKeyWords(String... keyWords) {
return this.readKeyWords(maxReadTimeout, keyWords);
}
/**
*
* 读取期望值
*
* @param timeOut
* 超时时间
*
* @param keyWords
*
* @return
*
* @throws CmdException
*/
public String readKeyWords(long timeOut, String... keyWords) {
String rv = "";
long nextTime = 0;
long endTime = System.currentTimeMillis() + timeOut;
do {
try {
String _rv = this.recieveEcho();
rv += _rv;
} catch (IOException e) {
nextTime = endTime - System.currentTimeMillis();
}
} while (!this.findKeyWord(keyWords, rv) && nextTime >= 0);
if (nextTime < 0)
System.err.println("Read TimeOut...Echo:\n" + rv);
return rv;
}
/**
*
* 读取期望值 排除command中含有的关键字
*
* @param timeOut
* 超时时间
*
* @param keyWords
*
* @return
*
* @throws CmdException
*/
public String readKeyWords(String command,long timeOut, String... keyWords) {
String rv = "";
long nextTime = 0;
long endTime = System.currentTimeMillis() + timeOut;
do {
try {
String _rv = this.recieveEcho();
rv += _rv;
} catch (IOException e) {
nextTime = endTime - System.currentTimeMillis();
}
} while (!this.findKeyWord(command,keyWords, rv) && nextTime >= 0);
if (nextTime < 0)
System.err.println("Read TimeOut...Echo:\n" + rv);
return rv;
}
/**
*
* 查找关键字
*
* @param keyWords
*
* @param str
*
* @return
*/
public boolean findKeyWord(String[] keyWords, String str) {
if (str == null || "".equals(str))
return false;
if (keyWords == null || keyWords.length == 0)
return true;
for (int i = 0; i < keyWords.length; i++) {
if (str.indexOf(keyWords[i]) != -1)
return true;
}
return false;
}
/**
*
* 查找关键字 排除command中含有的关键字
*
* @param keyWords
*
* @param str
*
* @return
*/
public boolean findKeyWord(String command,String[] keyWords, String str) {
if (str == null || "".equals(str))
return false;
if (keyWords == null || keyWords.length == 0)
return true;
System.out.println(str);
if(-1 != str.indexOf(command)){
str=str.substring(str.indexOf(command)+command.length());
for (int i = 0; i < keyWords.length; i++) {
if (str.indexOf(keyWords[i]) != -1)
return true;
}
}
return false;
}
/**
* 最短读阻塞时间
*
* @return
*/
public int getMiniReadIntervalMillSec() {
return miniReadIntervalMillSec;
}
public void setMiniReadIntervalMillSec(int miniReadIntervalMillSec) {
this.miniReadIntervalMillSec = miniReadIntervalMillSec;
}
/**
* 连接超时时间
*
* @return
*/
public int getConnectTimeout() {
return connectTimeout;
}
public void setConnectTimeout(int connectTimeout) {
this.connectTimeout = connectTimeout;
}
/**
* 最大读阻塞时间
*
* @return
*/
public int getMaxReadTimeout() {
return maxReadTimeout;
}
public void setMaxReadTimeout(int maxReadTimeout) {
this.maxReadTimeout = maxReadTimeout;
}
}