Java Telnet Socket: BufferedReader/BufferedWriter Java中的Telnet Socket：BufferedReader / BufferedWriter

Question

Java Telnet Socket: BufferedReader/BufferedWriter Java中的Telnet Socket：BufferedReader / BufferedWriter

5

我的服务器在23999端口上打开了一个telnet端口，当我输入telnet localhost 23999时，它会显示以下内容:

< BP-SAS ==> bplin19 !>telnet 0 23999
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
Please enter password to authenticate:
(here i give password for example abc123)   
Enter 'help' at any point to get a listing of all registered commands...
BAS> log set-info 1 ( commad i have entered and it does somthing )

现在，我不再像这样直接打开文件，而是必须编写Java代码来完成此操作。

连接到23999端口的主机
输入密码
输入命令

Socket soc=new Socket("192.168.9.7",23999);
  while(true){
  //create buffered writer
  BufferedReader bwin = new BufferedReader(new InputStreamReader(soc.getInputStream()));
  BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(soc.getOutputStream()));
  BufferedWriter bw1 = new BufferedWriter(new OutputStreamWriter(soc.getOutputStream()));
  String readFir = bwin.readLine();
  System.out.println(readFir);
        if(readFir.startsWith("Please")){
            System.out.println("Password Entered");
            bw.write("abc123");
            bw.flush();
            bw.close();  //close buffered Reader 
        }

        readFir = bwin.readLine();
        if(readFir.startsWith("Enter")){
            System.out.println("Enter command");
            bw1.write("log set-info 1");
            bw1.flush();
            bw1.close();  //close buffered Reader 
        }
        //readFir = bwin.readLine();
    }

这不起作用。实际上，我有点困惑应该采取什么方法。在读者/写者之间非常困惑。

请帮忙。

- VJS

你尝试过使用单个OutputStreamWriter吗？当你关闭第一个BufferedWriter（bw）时，你也会关闭套接字输出流。另外，当你执行这个操作时，stdout上会输出什么？ - CodeMonkey

@Jason - 在readFir = bwin.readLine();行出现了SocketClosed异常。 - VJS

1个回答

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- CodeMonkey · Accepted Answer

只需要一次获取socket的输入流和输出流(在while循环之外进行)。尝试像这样：

Socket soc = new Socket("192.168.9.7",23999);
//create buffered writer
BufferedReader bwin = new BufferedReader(new InputStreamReader(soc.getInputStream()));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(soc.getOutputStream()));
while (true) {
        String readFir = bwin.readLine();
        if (readFir == nul) break;
        System.out.println(readFir);
        if(readFir.startsWith("Please")){
            System.out.println("Password Entered");
            bw.write("abc123");
            bw.newLine();
            // instead might have to explicitly write "\r\n"
            // depending platform you're connecting from.
            bw.flush();
        }
        else if(readFir.startsWith("Enter")){
            System.out.println("Enter command");
            bw.write("log set-info 1");
            bw.newLine();
            bw.flush();
            bw.close();  //close buffered Writer
            break;
        } else System.out.println("Skip: " + readFir);
  }

如果您需要访问Telnet协议，最好使用像Apache Commons Net这样的库，而不是自己动手。