Question

java代码访问telnet,并受到返回值

各位大神好， 我想通过java代码访问telnet服务器，传送命令后受到返回值（注意：我需要telnet的返回值信息，不是cmd的返回值信息。我在网上找了好多都是返回的cmd的信息好像）





Answer 1

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

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

public class Shell {
private TelnetClient telnet = new TelnetClient();

private InputStream in;

private PrintStream out;

private char prompt = '$';// 普通用户结束

public Shell(String ip, int port, String user, String password) {
try {
telnet.connect(ip, port);
in = telnet.getInputStream();
out = new PrintStream(telnet.getOutputStream());
// 根据root用户设置结束符
this.prompt = user.equals("root") ? '#' : '>';
login(user, password);
} catch (Exception e) {
e.printStackTrace();
}
}

/**
* 登录
*
* @param user
* @param password
*/
public void login(String user, String password) {
// read()Until("login:");
readUntil("login:");
write(user);
readUntil("Password:");
write(password);
readUntil(prompt + "");
}

/**
* 读取分析结果
*
* @param pattern
* @return
*/
public String readUntil(String pattern) {
try {
char lastChar = pattern.charAt(pattern.length() - 1);
StringBuffer sb = new StringBuffer();
char ch = (char) in.read();
while (true) {
sb.append(ch);
if (ch == lastChar) {
if (sb.toString().endsWith(pattern)) {
return sb.toString();
}
}
ch = (char) in.read();
System.out.print(ch);
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

/**
* 写操作
*
* @param value
*/
public void write(String value) {
try {
out.println(value);
out.flush();
} catch (Exception e) {
e.printStackTrace();
}
}

/**
* 向目标发送命令字符串
*
* @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 disconnect() {
try {
telnet.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
// TelnetClient telnet = new TelnetClient();
try {
Shell she = new Shell("192.168.1.10", 23, "root", "123456");
System.out.println(she);
//执行的命令
System.out.println(she.sendCommand("ll"));
she.disconnect();

} catch (Exception e) {
// TODO: handle exception
}

}
}