Mockito:How to mock method called inside another method

Question

I am new to mockito and I am using mockito to test method which is calling another method and called method returns string. I tried but I am unable write test. Please help

public class MyClass {
  protected String processIncominData(String input) {
    String request = ...;
    ...
    String response = forwardRequest(request);
    ...
    return response;
  }

  public String forwardRequest(String requestToSocket) {
   String hostname = socketServerName;
    int port = socketServerPort;
    String responseLine=null;
    Socket clientSocket = null;  
    PrintStream outs=null;

    BufferedReader is = null;
    BufferedWriter bwriter=null;

    try {
        clientSocket = new Socket(hostname, port);
        outs=new PrintStream(clientSocket.getOutputStream());
        is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
        bwriter = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));

    } catch (UnknownHostException e) {
        LOGGER.error("Don't know about host: " + hostname + e.getMessage());
    } catch (IOException e) {
        LOGGER.error("Couldn't get I/O for the connection to: " + hostname + e.getMessage());
    }

    if (clientSocket == null || outs == null || is == null) {
        LOGGER.error("Something is wrong. One variable is null.");
    }
    try {
        while ( true ) {
            StringBuilder sb = new StringBuilder();
            sb.append(requestToSocket);

            String  request = sb.toString().trim();
            bwriter.write(request);
            bwriter.write("\r\n");
            bwriter.flush();
            responseLine = is.readLine();
            LOGGER.info("Socket returns : " + responseLine);
            //outs.println(responseLine);
            bwriter.close();
        }
    } catch (UnknownHostException e) {
        LOGGER.error("Trying to connect to unknown host: "+ e.getMessage());
    } catch (IOException e) {
        LOGGER.error("IOException:  "+ e.getMessage());
    }
    finally{
        try {
            outs.close();
            is.close();
            clientSocket.close(); 
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
    return responseLine;
  }
}

I want to mock xml response here to test processIncomingData method..This response is coming from socket server and I am sending request by socket client. I think socket will not matter if I can mock xmlResponse from socket. Please give any helpful answer

Show how `xmlResponse` is being generated. You need to use a mock at the line `String xmlResponse = ...;`. If this is an instance method call, use `Mockito` to mock the bean (read socket client). If this is a static call, use `JMockit` to mock the static call. — John B, Nov 25 '14 at 12:42
I am reading xml response from socket server. It is in string format like "123" etc — Lakshya, Nov 25 '14 at 13:17
Your unit test should not depend on a socket server. You should be mocking the client. — John B, Nov 25 '14 at 13:28
Post more code. Specifically, 1) the full line of code that retrieves `xmlResponse` 2) how `MyClass` gets the instance of the client it is using. — John B, Nov 25 '14 at 13:33

score 2 · Answer 1 · edited Jul 12 '18 at 12:17

2

You can try the spy method:

MyClass myClass = spy(new MyClass());
when(myClass.forwardRequest("foo")).thenReturn("bar");

then when you call

myClass.processIncominData("baz");

the response will be "bar" (if request is "foo")

PS: When you need to mock class under test it shows some problem with your design.

edited Jul 12 '18 at 12:17

AntoineB

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answered Nov 25 '14 at 12:35

talex

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4

But better refactor this to have thous methods in different classes. – talex Nov 25 '14 at 12:36
4

Generally considered bad practice to mock the class under test. – John B Nov 25 '14 at 12:41
@JohnB Yes. It is wy I'm added comment to separate class. – talex Nov 25 '14 at 12:42
Didn't realize that was a comment on your own post. Might have been better to edit your post to put the expansion in the body. – John B Nov 25 '14 at 12:44
@JohnB It was not part of answer, just general hint. But I edited my answer. – talex Nov 25 '14 at 12:50
Yes I agree It should be in different class but I have some limitations...@talex but code you have given is not working – Lakshya Nov 25 '14 at 13:18
OR please Let me know how to do it when second method is in different class? – Lakshya Nov 25 '14 at 13:28
@Lakshya not working? Real method is executed? Check parameter or replace it to `anyString()` – talex Nov 25 '14 at 14:58
no not working with anyString too..it breaks at when().thenReturn – Lakshya Nov 27 '14 at 07:13
I got it it was because of input steam..I mocket it and its working now..thank you – Lakshya Nov 28 '14 at 05:26

score 2 · Accepted Answer · edited May 23 '17 at 10:32

2

Now that you have posted it, the answer to how to mock it is here.

testing-java-sockets

edited May 23 '17 at 10:32

Community

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answered Nov 25 '14 at 13:49

John B

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but I am not using socket in my first method? – Lakshya Nov 27 '14 at 06:49

Mockito:How to mock method called inside another method

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