[SOLVED] How to get the Java stream for ExpectIt to drive Telnet

How to get the Java stream for ExpectIt to drive Telnet

How do I get the Java stream for telnet to use with the ExpectIt? Instead of using a Java library, such as Apache Telnet as below, using the actual Telnet client on Linux.

This is in the context of the man page from expect:

Expect is a program that "talks" to other interactive programs according to a script.

followup question with a much more narrow scope to a previous, vague, overly broad question where the following comment was made:

The library, as all the other Java libraries, uses standard Java streams which can come from a Telnet client, a socket connection, or any other stream source. Here is a telnet example: github.com/Alexey1Gavrilov/ExpectIt/blob/master/expectit-core/… – Alexey Gavrilov

Here is the example code:

package net.sf.expectit;

/*
 * #%L
 * ExpectIt
 * %%
 * Copyright (C) 2016 Alexey Gavrilov and contributors
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import static net.sf.expectit.matcher.Matchers.contains;

import java.io.IOException;
import org.apache.commons.net.telnet.TelnetClient;

/**
 * A telnet client example showing weather forecast for a city.
 */
public class TelnetExample {
    public static void main(String[] args) throws IOException {
        TelnetClient telnet = new TelnetClient();
        telnet.connect("rainmaker.wunderground.com");


        StringBuilder wholeBuffer = new StringBuilder();
        Expect expect = new ExpectBuilder()
                .withOutput(telnet.getOutputStream())
                .withInputs(telnet.getInputStream())
                .withEchoOutput(wholeBuffer)
                .withEchoInput(wholeBuffer)
                .withExceptionOnFailure()
                .build();

        expect.expect(contains("Press Return to continue"));
        expect.sendLine();
        expect.expect(contains("forecast city code--"));
        expect.sendLine("SAN");
        expect.expect(contains("X to exit:"));
        expect.sendLine();

        String response = wholeBuffer.toString();
        System.out.println(response);

        expect.close();
    }
}

Solution

You can spawn a telnet client process and connect to the process's input and output streams. Something like:

        Process process = Runtime.getRuntime().exec("telnet rainmaker.wunderground.com");
        StringBuilder wholeBuffer = new StringBuilder();
        Expect expect = new ExpectBuilder()
                .withOutput(process.getOutputStream())
                .withInputs(process.getInputStream())
                .withEchoOutput(wholeBuffer)
                .withEchoInput(wholeBuffer)
                .withExceptionOnFailure()
                .build();

Here is a link to the complete example.